VOLUME 20 , No.3, August 1986 . PRICE $ 5 . 0 0 Australia Post — publications No. NBP4724

JOURNAL OF

THE CLEAN AIR SOCIETY OF AUSTRALIA AND NEW ZEALAND

President: Dr. K. M. Sullivan AM

Secretary: R. W. Manuell

Treasurer: Dr. K. S. Basden

Postal Address:

Box 191, Eastwood, N.S.W. 2122.

BRANCH PRESIDENTS

ACT: T. O'Brien

NSW: J. D. Court

NZ: D. E. J. Ward

Old: J. S. McFarlane

SA: K. A. Webb

Vic/Tas: Dr. J. B. Robinson

WA: D. G. Saunders

EDITORIAL K. M. Sullivan 66

TECHNICAL PAPERS Werner Strauss Memorial Lecture and Congress Keynote Address. Trace Gas Trends in the Southern Hemisphere- G. B. Tucker 73 Congress Keynote Address. Reducing Air Pollution: An Economically Sound Investment -I. M. Torrens 77 Chemical Composition of Rainwater at New Plymouth, N.Z.

in 1981-82. - G. P. Ayers, R W. Gillett, V. Cernot 89

Soiling of Building Materials about Melbourne - An Exposure Study. - K. G. Martin, A. N. Souprounovich. 95

FEATURES Branch News

New Books

Clean Air Medal Award

Book Reviews

The International Union of Air Pollution Prevention Association (IUAPPA)

The Clean Air Society of Australia and New Zealand- 19th Annual Report and Statement of Accounts.

New Products

66

68,70, 108

68

69,70

71

86

87, 93, 94, 107

Victoria and Tasmania Branch Symposium: High Temperature Incineration of Hazardous Waste. 101

BRANCH CORRESPONDENTS

ACT: Dr. A. J. Jakeman

NSW: Steve Stanley

NZ: Ron Pilgrim

Qld: Dr. N. Bofinger

SA: J. Tucker

Vic/Tas: Jack Chiodo

WA: D. B. Sykes

The opinions expressed by authors and contributors are their own and do not necessarily represent the view of the Society.

EDITOR Hanns F. Hartmann, 22 Anderson Road, East Hawthorn, Vic. 31 23 Tel. 20 4671

ASSOCIATE EDITOR Sylvia J. Mainwaring

EDITORIAL BOARD H. F. Hartmann R. G. Gillis Sylvia J. Mainwaring J. O'Heare P. G. Williams

ADVERTISING Enquiries should be directed to Miss Ann Sykes, C/- Appita, 191 Royal Parade, Parkville, Victoria 3052. Phone: (03) 347 2377

PRINTER J. G. Holmes Pty. Ltd. (03) 51 6961

SUBSCRIPTIONS Enquiries about subscriptions, payment of invoices, and requests for back numbers should be directed to the Circulation Manager, Mr. A. Crapp, Box 191 Eastwood, N.S.W. 2122 Australia ' Phone: (02) 266 0661

Publication is quarterly in February, May, August and November.

Annual Subscription rates (Inc. postage) for non-members and libraries:

Australia and New Zealand $A16.00

Elsewhere $A20.00 Single copies $A5.00

CLEAN AIR is listed in Current Contents

EDITORIAL

The 7 th World Clean Air Congress and Exhibition of The International Union of Air Pollution Prevention Associations is with us. This Congress which is being hosted by your own Society, represents the culmination of an enormous effort that has been put into its organisation, by a large number of Members of the Society, whose reward will be the hold­ing of a successful Congress.

The work of all those who have con­tributed to the Congress should be recog­nised and applauded since it represents a considerable personal input in terms of effort and time, to enable the staging of the Congress. To all of those volun­teers, I express my heartfelt thanks and I am sure that I echo the thanks of all delegates to the Congress.

The success of the Congress now rests largely with the participants, who by their discussion, exchange of views and sharing of different experiences, will return to their respective countries with a better understanding of the needs and requirements for cleaner air throug-hout the world.

The occasion of the Congress is the time when I personally shall move on from the Presidency of The Inter­national Union, a position I assumed at the time of the last Congress in May 1983. The past 3 years have been re­warding and have afforded me the op­portunity to visit many of the member bodies of IUAPPA and also to attend, address and partake in many of the Clean Air Meetings and Conferences that have been held by various Mem­bers of the IUAPPA during that time. However, most significantly, the achievments which have occurred within IUAPPA during the past 3 years have been IUAPPA gaining Membership of the Union of Inter­national Technical Associations thus

providing IUAPPA with consultancy status to the United Nations. IUAPPA decided to take positive initiatives to assist developing countries to come to grips with air pollution control. With the prime objective of assisting third world countries IUAPPA propose to publish a Compendium which in addi­tion will be of interest to all persons concerned with air pollution and its control. Positive action has been taken to attract new members to IUAPPA and to alter the membership requirements so that membership can come from Countries of the World which were previously precluded, due to their inability to satisfy membership requirements. One of the more signifi­cant achievments has been the gaining of United Nations support to the extent of US $25,000.00 to provide assis­tance in bringing persons from develop­ing countries to attend the 7 th Congress. This in a very tangible way will assist IUAPPA to ensure that the requirements for and means of achiev­ing cleaner air within third world coun­tries is passed on to persons who are best able to effect its achievment.

At the end of August I will hand over the IUAPPA Presidency to my suc­cessor Dr. Louis Clarenburg of the Netherlands, with those normal feelings of regret, but knowing that Louis will continue to advance IUAPPA and also knowing that whilst I am able to con­tinue as a Member of the Executive, I shall have the opportunity of continu­ing an input, with the ultimate object of providing the World with a little cleaner

K. M. SULLIVAN

SOCIETY NEWS

During his overseas trip in June our President visited Drs Schwarz and Grefen of VPI, Federal Republic of Germany and attended the opening of the Air Pollution Control Association Annual Meeting in Minneapolis, U. S. A He had the opportunity to have dis­cussions with Mr. Steve Hart, Execu­tive Vice President of APCA Professor Joe Soporowski and Mr. Dick Scherr the immediate past and incumbent Pre­sidents of A P C A Whilst at the APCA Meeting Dr. Sullivan, in his capacity as President of IUAPPA addressed the Opening Session of the Meeting, draw­ing their attention to the forthcoming 7th World Clean Air Congress and wishing all attendees at the APCA gathering a successful meeting on behalf of both IUAPPA and CASANZ.

BRANCH NEWS

Victoria and Tasmania

Environment Protection Authority Staff Movements.

In December of last year, Doug Munro was appointed to the position of Manager, Assessments and Research within the Air Quality Branch of the E. P. A. Doug has diplomas in both chemistry and chemical engineering. He spent some nine years in the gas supply industry and the oil industry before joining E. P. A in 1973.

More recently, Brian Robinson, pre­sident of the local Branch of the Society, was appointed to the position of Deputy Chairman of E.P. A. Since completing his Ph.D. in chemistry in 1968, Brian has spent several years in industry and in universities, before joining E. P. A. in 1975. Since then he has held a number of positions in E.P.A. and also spent some three years in the Department of Premier and Cabinet

Jeff Wright has recently resigned as Chairman of E.P.A. to take up the appointment of Chief General Manager of the Department of Agriculture. Dur­ing his three years with E.P.A. Jeff instituted a number of important changes, including a complete revision of the Environment Protection Act which gave E.P.A. significant new powers.

Queensland

In order to improve communication with country members in Queensland, the Queensland Branch Committee has instituted the practice of videotaping Branch meetings addressed by an ex­ternal speaker. These tapes will be made available to non-metropolitan members on a loan basis.

Recently, a joint meeting was held with the Institution of Engineers (Chemi­cal Branch) and the Institution of Chemi­cal Engineers and was addressed by Dr. David Slater on the topic of Risk Analysis.

Dr. Slater is the chairman of Technica Ltd, London. He obtained his B. Sc. and Ph.D. in Physical Chemistry and spent 9 years in academia with par­ticular emphasis on combustion pro­cesses. He has spent 10 years in the risk assessment field A former partner with Cremer and Warner specialising in en­vironmental and hazards work, Dr. Slater founded Technica Ltd, a group

66 Clean Air/August 1986 Vol. 20/3

of professionals providing an inter­national consultancy service in the area of hazard indentification and risk as­sessment Dr. Slater is in Australia as Visiting Professor at the Warren Cen­tre for Advanced Engineering at the University of Sydney.

The recent toxic and fire disasters in India and in Mexico have highlighted the potential dangers associated with the chemical process industry. More stringent controls covering fire, explo­sion and toxic emissions from chemical facilities must soon be anticipated in Australia Such controls have recently been instituted in the UK and more generally in the EEC nations.

The technology of hazard assess­ment has grown out of the nuclear in­dustry and with substantial modification is now applied to the chemical and related industries. Dr. Slater discussed the general strategy of risk assessment particularly in relation to the Aus­tralian environment.

Mr. Josef Franz, recently retired from the position of Chief Engineer with Lurgi (Aust) has addressed a Branch meeting on July 8, the topic being ' Precipitators'.

New South Wales

INDOOR AIR POLLUTION

On April 1, David Johnson, 0IC Air Assessments ©if the SPCC of NSW presented to the NSW Branch members and friends, a background to the recent de-velopments in oradoor air pollu-tion. This was in response to a survey we conducted last year which indicated that a topic high on members' list of interest was indoor air pollution,

Historically we have tended to classify our living and working environments into outdoor (ambient) and workplace (occupational) categories. Significant gains in obtaining and maintaining ac­ceptable environments for these classi­fications have been made by means of improved technology, control pro-

May Journal wrongly marked The May issue of the Journal was erroneously marked " February 1986" on the cover.

An adhesive label is included so you can correct this mistake. With apologies

The Editor

grammes and regulatory authority. Non-occupational indoor air pollu­

tion is a third and significant environ­mental classification which has been part of our living since the days of our cave dwelling predecessors. Depend­ing on a person's age and lifestyle, individuals can spend from 33 to 100 per cent of their time indoors.

For a number of years there has been a growing amount of work overseas on the measurement of air quality inside buildings of a residential or public building nature. Although standards have not been set for" non occupational" air quality, one would expect, however, that levels of concern would be well below occupational exposure stan­dards because the general community population includes those who would be less healthy and more sensitive to pollution effects.

With the increasing cost of fossil fuel and subsequent increase in the cost of heating or cooling there has been a ten­dency to improve insulation in homes, reduce air changes and use alternative combustion fuels in the home or in public places. One possible conse­quence of energy conserving initiatives such as these could be the creation of increased indoor air pollution.

The State Pollution Control Com­mission was awarded a National Energy Research, Development and Demon­stration Council (NERDDC) grant to investigate indoor air pollution and its interplay with energy conservation. The programme of studs will include the monitoring of the indoor environ­ment of a range of houses, particularly those which used gas or woodburning appliances and that have a relatively high level of occupancy.

The research into household pollu­tion will be carried out by the Commis­sion and Dr. Frank Cattell from the Centre for Environmental and Urban Studies at Macquarie University. A range of parameters will be measured both indoors and outdoors and will include nitrogen oxides, carbon mon­oxide, particles, radon, temperature andhumidity. These parameters will be measured continuosly while batch measurements will be made of for­maldehyde, polycyclic aromatic hyd­rocarbons-and ventilation flow rate. Ventilation flow rate, and of course appliance type, are the two most impor­tant factors which can influence indoor air pollution levels.

Early indications are that levels of nitrogen dioxide in rooms using certain types of gas appliances can be up to 3 and 4 times higher than the National Health and Medical Research Coun­

cils' ambient goal of I6pphm (1 hour average).

The Commission is looking for mem­bers of the general public living in the Sydney metropolitan area who would be prepared to offer their houses for testing purposes. The tests will be car­ried out with the minimum of disruption to the household, in most cases involv­ing only the temporary installation (3 day) of monitoring equipment In ap­proximately 15 houses, however, equip­ment may be installed from 1 to 2 weeks.

Public response has so far been dis­appointing and any offers of homes by our New South Wales Society mem­bers would be most welcome.

If any member wishes to discuss the possibility of offering their house for the study (the first of its kind in Australia) couid you kindly phone Maria Kovacs on 265 8015 or David Johnson on 265 8011.

If you prefer, you could drop a line to the Secretary, State Pollution Control Commission, GPO Box 4036, Sydney, 2001, providing details of your heating and cooking facilities, types of insula­tion or other details which you consider could make your house a candidate for "elevated" indoor air pollution.

J O H N COURT, N S W Branch President

Jerry Wesolowski, an overseas visitor, w i l l be present ing a paper on indoor air pol lut ion on April 30 1S87 at a Specialist Group Meeting which is one of the features of RACI's Ninth Australian Symposium on Ana-lytical Chemistry to be held in Sydney from ApriI 27 to May 1, 1937.

Jerry Wesolowski is Chief of the Air' and Industrial Hygiene Laboratory of the California Department of Health Services and a lecturer in the Civil Engineering Department of the Uni­versity of California, Berkeley, where he teaches a course in indoor and out­door measurement methods. He received his Ph.D. in nuclear physics and his early research interests were in the area of nuclear reactions. His research on the use of nuclear techniques, par­ticularly neutron activation analysis, to measure trace elements in ambient air led to his present career in environmen­tal science. He is on a number of com­mittees, including the Clean Air Scien­tific Advisory Committee to the Science Advisory Board of the U. S. environ­mental Protection Agency. The com-

Clean Air/August 1986 Vol. 20 /3

67

mittee advises on the scientific and technical aspects determining criteria for Federal air quality standards, related research needs, pollution sources, and strategies to maintain air quality stan­dards. He is the founder of California's Indoor Air Quality Program.

Mr. Wesolowski will also be travell-ing to most of the state branches to talk on indoor air pollution and perhaps other local matters of importance.

NEW BOOKS

IUAPPA COMPENDIUM

The International Union has decided to produce a textbook on clean air objec­tives, legislation and administrative practices throughout the world. Due for publication at the end of 1987, the IUAPPA Compendium will rely prin­cipally on contributions from IUAPPA member associations. The book is in­tended to help countries which are in the process of developing their legisla­tive codes and systems for air pollution control, and it will also be of interest to legislators and pollution control ad­ministrators in the major industrialised nations.

VDI-Bericht 475 Fibrous Dusts-Measurement, effects, prevention From October 4 to 8 1982, the VDI-KOMMISSION REINHALTUNG DER LUFT, Dusseldorf, organised-in co-operation APPA and CITEPA, Paris - an international interdis­ciplinary conference on fibrous dusts, which was held in Strasbourg/France.

TheVDI-Bericht 475 comprises the complete lectures and selected state­ments of the above-mentioned conference according to the following topics: — Techniques for fibre measurement — Results of ambient air measure­

ments — Epidemiological findings — Effect-related experimental results — Risk assessment — Emission sources — Emission Control — Substitution of potentially noxious

fibres. The report presents a comprehen­

sive survey of the medical and technical progress made in solving the problems involved with human exposure to fibres in the workplace atmosphere and in the environment

The VDI-Bericht 475 (5655 pp., 404 fig., 138 tab.; DM 298. ---- ) is available from: VDI-Verlag GmbH, P.O. Box 1139, D-4000 Dusseldorf 1.

68

Rear Admiral Philip Graham Sharp was born in Yorkshire, England on 23 rd November, 1913. He was educated at Northhampton School and Tynemouth High School and entered the Royal

The Clean Air Society's Medal was de­signed and executed by noted Melbourne sculptor Michael Meszaros. It was previously awarded io:

Alderman F. Purdue. C8F New South Wales

Louis Layton. Victoria Dr. Werner Strauss, Victoria R T. Douglas. New Zealand

Naval Volunteer Reserve in 1937 and served throughout the i 939-45 War in destroyers, in command from 1943 onwards. He was awarded the Dis­tinguished Service Cross in 1942 and was mentioned in despatches the fol­lowing year. In 1947 he transferred to the Royal Navy, in which he served until his retirement in November, 1967. He was appointed to the rank of Rear Admiral in 1965 and his final appoint­ment was Flag Officer Sea Training. He was appointed ADC to the Queen in 1965 and was made a Commander of the Order of the Bath in 1967. From 1968-1980 he was Director (later Sec­retary Genera!) of the National Society for Clean Air. He was a member of the United Kingdom Clean Air Council-a Statutory Body - from 1968 until its dissolution in 1979. He was Chairman of" that Council's Steering Committee from 1974-1979. In 1978, Admiral Sharp was appointed Director General of the International Union of Air Pollu­tion Prevention Associations. Among other honours he was made a Freeman of the City of London in 1978, a Fellow of the Royal Society of Arts and a Com­panion of the Institution of Chemical Engineers. In 1983 he was awarded the Silver Medal of the City of Paris in recognition of his services to clean air.

In this, his second career in air pollu­tion control he established a worldwide reputation as an expert on the technol­ogy of air pollution control as well as the backing legislation.

Philip Sharp visited Australia twice, on the occasions of the Clean Air

Clean Air/August 1986 Vol. 20/3

REAR ADMIRAL PHILIP SHARP AWARDED CLEAN AIR MEDAL

The Council of the Clean Air Society of Australia and New Zealand has awar­ded the Society's Clean Air Medal to Rear Admiral Philip Sharp. CB. DSO, lUAPPA's Director General, for ser­vices to International Control of Air Pollution.

The medal which has been awarded only four times previously was to be handed to Philip Sharp at a special ceremony during the Opening Session of the Seventh World Clean Air Con­gress. Unfortunately, ill-health has pre­vented Philip Sharp from visiting Australia at this time much to the regret of his many friends in this country. Instead the medal was handed to him by our President, Dr. K. Sullivan dur­ing his recent visit to England.

The award was made at a small ceremony witnessed by Air Com­modore John Langston, Secretary General of the National Society for Clean Air, and his wife Marylin, Mr. Max Beaumont immediate past Presi­dent of the National Society of Clean Air, Dr. Joop van Ham, Secretary of CLAN the Netherlands clean air society and Mrs. van Ham and by Mrs. Sharp. In his response to the award Rear Admiral Sharp expressed his thanks to the Society and his disappointment that he was unable to be present at the 7 th World Congress and to receive the award then, as had originally been planned. He conveyed best wishes to the Society for the Congress and also to his many friends within our Society.

Society's 1978 Conference in Brisbane and the 1981 Conference in Adelaide. He addressed both meetings on the sub­ject of the work of the International Union.

We regret that Philip Sharp is pre­vented from being with us this time and wish him many years of good health to pursue his hobbies of golf, fishing and mode! making

CALL FOR PAPERS

NINTH AUSTRALIAN SYMPOSIUM ON ANALYTICAL CHEMISTRY

Sydney, Australia, 27 April -1 May, 1987 .

The organising committee invites the submission of high standard, original papers on any aspect of analytical chemistry for either verbal or poster presentation.

Intending contributors of both papers and posters must submit a title and 200 word abstract BEFORE OCTOBER 1st, 1986 to:-

MR. J. EAMES, 9 AC SECRETARY, P.O. BOX 137, NORTH RYDE, N.S.W.,2113, Australia. 9 AC Symposium will present recent

advances in technique specialisations including GLC, HPLC, ICP, MS, IC, FIA, AAS, FTIR. The range of dis­ciplines covered will include agricultur­al, clinical and biological, computers and laboratory automation, environ­mental, food and carbohydrates, pharma­ceutical, occupational hygiene, electro­chemical and mineral.

The excellent location, dis­tinguished invited speakers, and a wide ranging scientific and social pro­gramme make 9 AC an outstanding destination for 1987.

BOOK REVIEWS

AIR POLLUTION MEASUREMENT

A Practical Guide to Sampling and Analysis Second Edition

Edited by: L M Ferrari, D C Johnson, H B Wortham Sponsored by: The Clean Air Society of Australia and New Zealand P O Box 161, Eastwood, New South Wales, 2122

This book comprises 59 papers and 15

Australian Standards compiled for the intensive training course - Air Pollu­tion Measurement A Practical Guide to Sampling and Analysis- sponsored and organised by The Clean Air Society of Australia and New Zealand The course " is aimed at assisting engineers, chemists and technical officers to a bet­ter working knowledge of air monitor­ing sampling and analysis." Accordingly, the papers are by people with expertise in air pollution measurement Of note is the significant number of contributions by members of the State Pollution Con­trol Commission of New South Wales.

The papers and Standards are divided into 9 sections. These are listed here to show the topics dealth with: (1) Monitoring in the Environment (2) Measurement of Atmospheric

Pollutants: Particles (3) Measurement of Atmospheric

Pollutants: Gases (4) Characterising Conditions in Stacks (5) Source Sampling and Analysis of

Particles (6) Specific Industrial Pollutants (7) Source Instrumental Analysis (8) Samples and Laboratory Analysis (9) Compendium of Standards

This book would serve as a good reference for people engaged in the operation and maintenance of instru­ments and equipment used for monitor­ing pollutant emissions and ambient air quality. Measurement methods, instru­ments and equipment likely to be en­countered in practice are described and discussed. The quality and perfor­mance of instrument types, specific instruments and other equipment related to air pollution measurements are com­mented upon. Recommendations and operating suggestions, based on the experiences of the authors, are also included

R. Oleszcyk

AIR POLLUTION MEASUREMENT. A PRACTICAL GUIDE TO SAMPLING AND ANALYSIS.

2nd Edition. Edited by L. M. Ferrari, D. C. Johnson and H.B. Wortham.

The Clean Air Society of Australia and New Zealand who sponsored this manual aimed the book at "assisting engineers, chemists and technical officers to give them a better working knowledge of air monitoring, sampling and analy­sis".

The present trend for pollution mon­itoring is for industry to oversee their

emission levels and state pollution agencies only becoming involved to enforce standards where necessary. As more and more responsibility falls upon industry to control emissions, so increases the necessity for engineers and chemists to understand the theoretical and prac­tical side of air pollution measurement

This book is truly a practical guide to air pollution sampling and analysis. Little theory is quoted but it is not com­pletely overlooked, for if the reader needs to follow up on any points then reference material listed at the end of each chapter makes this an easy task.

The Second Edition of "A Practical Guide to Sampling and Analysis" con­sists of nine sections. Each section has several chapters which are written by authors from the NSW SPCC, tertiary institutions or industry.

Section one sets out the background of environmental monitoring but the main emphasis is on correct sampling, sampling errors, pitfalls and preventa­tive maintenance. Sections two through to eight cover specific tests and pro­cedures for measuring particulate and gaseous pollutants. Sections seven and eight cover more specifically laboratory and in-situ analysis. Section nine is a compendium of Australian Standards covering monitoring of ambient air.

Even though the book is about the tests state pollution authorities carry out it still proves to be an excellent reference for air pollution sampling and analysis for industry. It provides indus­try with an understanding of the type of tests state pollution control authorities carry out when monitoring ambient air. Some particular monitoring pro­cedures are covered, e.g isokinetic sampling, and in each case potential pitfalls and equipment maintenance checks are highlighted

G. Palmer

John McCormick-ACID EARTH: THE GLOBAL THREAT OF ACID POLLUTION

187 pages. Publisher Earthscan Lon­don, UK 1985. Price in England £3.95

This well researched (168 references) journalistically written book is com­prehensible to both scientists and in­terested lay-people. It focusses on the need for global co-operative govern­mental action in order to make much greater reductions in SOx and N O x

emissions than are currently planned if "acid rain" is to be effectively controlled

The author accepts that "acid rain" is a misnomer for acidic deposition, but

Clean Air/August 1986 Vol. 20/3

69

apparently also accepts the term "acid rain" is here to stay. He was a little con­fused over some aspects of smog- the London smog scene was overcome fay cessation of burning soft coal in domes­tic grates, and later he ignores the role of hydrocarbons in the photochemical smog process. There are no references to Australia, but then the acid rain scene here is insignificant compared with the scale of the problem in the northern hemisphere.

Overall, however, this is a useful book for those commencing a study of the topic, including teachers, students and legislators. The list of collaborators includes many famous names just as the contents include some famous emit­ters, such as the INCO plant at Sud­bury which has managed to halve its S0 2 emissions from 1980 levels.

R. W. Manueli

Mobile Source Emissions including Poiycyclac Organic Species

Edited by: D. Rbndia, M. Cooke & R. K. Haroz. Published by; D. Reidel. Distributed by: D. A. Book (Aust) Pty. Ltd. Price: A$49.40

This volume constitutes the published proceedings of a NATO workshop held in Belgium in late 1982. According to the editors in their summary chapter the NATO workshops are convened to bring together a limited number of experts from member countries who have expertise in different fields and represent all sections of the scientific community to achieve one or more of the following objectives:

(a) exchange of thought at the fron­tiers of knowledge or at the fron­tiers of the different fields;

(b) review and critical assessment of the state of the art;

(c) formulation of recommendations for future research directions;

(d) formulation of plans for large inter­national scientific experiments.

This meeting very creditably attempted the first three objectives but found that any overall consensus was not possible because the lack of standardisation of test and measurement procedures pre­vented any valid comparisons being made. The meeting was able to do little more in this regard than recognise the need for such standardisation before formulation of large scale international experiments could be a reality.

The book itself is a fine and diverse collection of papers ranging from ex­

tensive reviews to reporting of recent research results all dealing directly with automobile emissions. Topics covered include: the relationship bet­ween the fuel and engine operating characteristics and emissions; the as­sociation between receptor emissions and effects; techniques and problems associated with analysis and trends in fuel usage. Included is the 1980 Oil Companies International Study Group for Conservation of Clean Air and Water (CONCAWE). This is the extrapolation of an earlier 1978 CON­CAWE report on the national use of fuels in private transport to the un­leaded case.

The book represents a fine body of technical data but more importantly it seeks out and highlights the unresolved pollution issues associated with the present and future use of the private automobile.

S. J. Maiowaring

Destruction and Disposal of FCBs by Thermal and Non Ther­mal Means By: D. G. Ackerman et al Published by: Noyes Data Corpora­tion, Park Ridge, New Jersey Price: USS 48.00 This book has been compiled from guideline documents prepared for the USEPA by T.RW.Inc., California. It contains the present state of the art recommendations for evaluating facilities for dealing with PCBs and therefore has value to regulatory agencies and facility operators. It should be emphasised that the book is not an official EPA publica-tioa Because it has been printed cheaply and from two existing reports, a certain amount of material in duplicated. How­ever, this disadvantage is outweighed by the advantage of having available such detailed and up to date informa­tion at an acceptable price.

The disposal of PCBs is a problem facing all governments as more and more equipment particularly electrical capacitators and transformers, con­taining these materials is taken out of service. The first half of the book deals with combustion methods and includes as an Appendix the US Federal Regis­ter containing the Rules and Regulations concerning PCBs. The second portion of the book describes and evaluates alternative technologies for clean up and disposal including adsorption, catalysis, plasma destruction and bac­terial activated sludge techniques.

S. J. Mainwaring

NEW BOOK

VD3-Bericht 494 Safe handling of f lammable dusts FromOctober26 to28, 1983, the VDI-Commission on Air Pollution Preven­tion in the Association of German Engineers( VDI-KOMMISSION REIN-HALTUNG DER LUFT), Dusseldorf, organized an interntional comference on safe handling of flammable dusts, which was held in Nurnberg.

In spite of constant endeavours to improve safety techniques, dust fires and dust explosions are still imminent; they may cause extensive damage and cause loss of lives. The VDI-Commission of Air Pollution Prevention organized conferences on this subject already in 1970 and 1977. The above-mentioned conference was based on new experience meanwhile gained in research and de­velopment especially in simulated field tests on a laboratory scale as well as on a large scale. It has been organized in order to present the technical progress to & large number of experts by ack­nowledged speakers from home and abroad.

The VDI-Report comprises the lec­tures of this conference submitted by the authors: parts of them are much more detailed than the spoken lectures. The topics are as follows: - Safety aspects with regard to fire

and explosion hazards caused bv flammable dusts

- Safety regulations and their appli­cation in practice

- Investigations into the course of dust explosions

- Prevention of dust fires and dust explosions

- Inerting - Ingnition sources - Explosion protection by construc­

tional measures - Practical application of protective

measures. It is true, that the avoidance of dust

explosions will not entirely be possible in the near future, but further reduction of such events can be achieved by con­tinuous research, improvement of inter­communication, and application of adequate measures.

The VDI-Bericht 494(323 pp., 421 fig., 47 tab.: DM 180.--- ---) is available from: VDI-Verlag GmbH, P.O. Box 1139, D-4000 Dusseldorf 1, FRG.

70 Clean Air/August 1986 Vol. 20/3

THE INTERNATIONAL UNION OF AIR POLLUTION PREVENTION

ASSOCIATION

By the end of the meeting a draft of the proposed' Constitution of the Inter­national Union of Air Pollution Pre­vention Associations' had been com­pleted and was signed by all the rep­resentatives present It identified the following specific objectives of the International Union:

The Union owes its existence to initi­atives taken by the Air Pollution Con­trol Association( APCA) of the United States which go back as far as 1957. A Committee consisting of past pre­sidents of the Association proposed statutes for an 'International Commis­sion on Air Pollution' to its Board of Directors who accepted the proposal in 1958.

A grant to APCA by the Division of Air Pollution of the United States Public Health Service enabled that organisa­tion to invite the representatives of five other national organisations to a meet­ing in Washington, D. C. on 18-19 June 1964. The following assembled for that meeting.

Asociacion Argentina Contra la Contaminacion del Aire, Dr. Jose A. Rispoli, Presidente. Association pour la Prevention de la Pollution Atmospherique, France, M. le Professeur Andre Roussel Kommission Reinhaltung der Luft, Germany, Ministerialdirektor a.D. Dipl. Ing. Hans Stephany. National Society for Clean Air, Great Britain, Mr. Arnold Marsh, Director. Kanto- Shin-Etsu Heat Control Society, Japan, Mr. Takahide Taga, Chief Director and Executive Secretary. Air Pollution Control Association, United States of America, Dr. C. E. Barthel, Jr., Chairman, Internation Affairs Committee. The meeting was chaired by Dr. C. E. Barthel Jr. The purposes of the meet ing were defined as:

1. To develop mechanisms for the exchange of information between the six national air pollution pre­vention associations.

2. To consider the desirability of an international union of air pollution prevention associations.

3. If desirable andfeasible, to prepare a draft of a proposed constitution for an appropriate body.

The discussion established that the total objectives of each of the national associations were strikingly similar but that organisational structure and mem­bership varied widely. It was agreed that an international body would be desirable but that it would need an ex­tremely loose organisation.

Clean Air/August 1986 Vol. 20/3

71

(a) To promote a uniform nomenclature of scientific and technical terms relating to air pollution and its con­trol, and to facilitate progress in the uniform interpretation and under­standing among nations of specific words or phrases.

(b) To promote uniform methods of measurement of air pollution.

(c) To interchange information related to air pollution and its control and to provide channels to accomplish this purpose.

(d) To improve and expand training in scientific and technical fundamen­tals of air pollution and its control

(e) To promote public understanding throughout the world, of the dangers, causes, and means of prevention of air pollution.

(f) To promote scientific and techni­cal research and development in air pollution and its control and develop and publish international scientific and technical recommen­dations for air pollution control.

(g) To encourage participation in and support of air pollution research, development, and application by government, industry, commerce, research laboratories, technical societies, and other qualified organ­isations.

(h) To develop appropriate liaison with other national and inter­national scientific and technical organisations concerned with activi­ties related to air pollution.

(i) To recommend the adoption of in­ternational scientific and technical air pollution standards, and periodi­cally review such standards,

(j) To stimulate the establishment of national air pollution programmes and associations.

(k) To sponsor international conferen­ces on air pollution.

It was further decided that the chair­man should continue to serve as head of the Committee of representatives and should endeavour to stimulate com­munication, adoption of the constitu­tion and take the necessary steps to activate the Constitution in accordance with the draft Constitutioa After each association had had the opportunity to examine the draft, the chairman was able to announce unanimous ratifica­tion on 8 January, 1965.

An Executive Committee with a rep­resentative of each association was established on 2 July, 1965. The Executive Committc then selected London as the venue for the first General International Congress to be held in October 1966 and to be hosted by the National Society for Clean Air

DipLIng. H. Stephany Mr. Stephany died before the Congress and Dr. Schachmann took his place.

Dr. J. A. Rispoli

of Great Britain. Consistently with the intent of the constitution, Sir Alan Wilson and Mr. Arnold Marsh, both associated with the above Society were elected first President and Secretary of the International Union. The principle that the President should always be from the organisation hosting the next World

Congress has been followed since. Executive Committee meetings have since been held on numerous occasions, the first in Buenos Aires in November, 1965.

Six Congresses have so far been held 1. London, 1966 -

President Sir Alan Wilson 2. Washington, 1 9 7 0 -

President: Dr. D.E. Barthcl Jr. 3. Duesseldorf 1973-

President; Dr. Schachmann 4. Tokyo 1977-

President Mr. Buzacmon Shindo 5. Buenos Aires 1 9 8 0 -

President Dr. Jose A. Rispoli 6. Paris 1 9 8 3 -

Prcsident Dr. Michel Sommer the International Secretariat was es­tablished at the office of the National Society for Clean Air of Great Britain in Brighton and Rear Admiral P. G. Sharp, D.S.C. was appointed Director General.

Since its foundation other national organisations have joined the Union which now has the national organisations from the following Countries as full members:

Argentina Australia and New Zealand Belgium Brazil Federal Republic of Germany Finland France Italy Japan The Netherlands Norway Republic of China (Taiwan) Singapore South Africa Switzerland United Kingdom United States of America

and Canada Yugoslavia In addition, Saudi Arabia became a

contributing Associate and the follow­ing were admitted as observers:

Greece Peru India Spain Israel Uruguay Mexico A meeting of the Executive will be

held during the Seventh World Con­gress in Sydney when the present Presi­dent, Dr. K.M. Sullivan, A.M. will hand over to his successor. Dr. L.A. Clarenburg of The Netherlands whose organisation will host the next World Congress in the Hague in 1989.

As air pollution tends to increase with industrialisation, the need for and the activities of the International Union will tend to increase as time goes on.

72 Clean Air/August 1986 Vol. 20 /3

Werner Strauss Memorial Lecture and

Congress Keynote Address

TRACE GAS TRENDS IN THE SOUTHERN HEMISPHERE

Dr, G.B. Tucker

Dr. Tucker is Chief of the CSIRO Divi­sion of Atmospheric Research in Aspen-dale, Victoria Previously he was Assistant Director (Research and Development) in the Bureau of Meteor­ology and foundation Officer-in-Charge of the Commonwealth Meteorology Research Centre.

SUMMARY

Increasing concentrations in the South­ern Hemisphere of four of the more important 'green-house' trace gases and one associated trace gas are des­cribed— on the basis of measurements at Cape Grim, Tasmania Current yearly rates of increase and the average levels attained in 1986 are: carbon dioxide, 0.4 percent, 345 ppmv, methane, +1.3 percent, 1600 ppbv; nitrous oxide, +0.3 percent, 313 ppbv; Freon-11, +5 per­cent, 225 pptv; and methyl chloroform, +6 percent, 115 pptv. Recently repor­ted analyses of air bubbles in Antarctic ice cores confirm that from fairly cons­tant levels in the 17th and 18th cen­turies, nearly all of the increases for carbon dioxide, methane and nitrous oxide have occurred since about 1850.

INTRODUCTION

Over the past 25 years, scientific in­terest in atmospheric chemistry has increased considerably. The main reason has been the observed steady rise in some of the trace gas concentrations, particularly those that have absorption bands in the infra-red region and thus affect out-going terrestrial radiation. Indeed, in the last ten years research in this area has grown enormously. A great deal of attention has been paid to the so-called 'green-house' effect of carbon dioxide and possible consequential climate changes over the next50 to 100 years (1).

Recently, however, three develop­ments have occurred that substantially

increase both the certainty and the proximity of substantia! climatic change (2). First, there has been a significant improvement in understanding both the causes of observed trace gas increases and their effects on the atmosphere's heat balance and climate. Second, it has been shown conclusively that the combined effect of trace gases other than carbon dioxide, previously thought to have been of only minor conse­quence to the thermal balance of the atmosphere, will cumulatively double the radiative effect of carbon dioxide during the next century. Third, a signal has now been detected above the noise level of fluctuating near-surface global temperatures that is consistent with the calculated warming effect of the carbon dioxide increase since the mid-nine­teenth century. And there is some sug­gestion that an associated rise in sea level can also be detected (3).

Research objectives can be con­sidered in several parts:

to understand the reasons why these trace gas concentrations in the atmosphere are increasing; and to do this sufficiently well to be able to pre­dict future levels with confidence;

to calculate the primary radia­tive effects of both observed and predic­ted future increases on atmospheric temperatures; and, in the case of carbon dioxide, to calculate the effect of higher concentrations on the biosphere;

to include these primary effects and more complex feed-back processes in a quantitative synthesis of the overall climate response to these changes, in both the atmosphere and the oceans; and to calculate the net environmental change with minimum uncertainty;

and, most difficult of all, to begin to assess the socio-economic effects of these changes.

Progress has been made in the first three of these parts. The general level of uncertainty associated with them has now been reduced to levels where it is

becoming expedient to begin to think of the way in which society might be able to adapt to these changes, particularly on a regional basis. Significant change is inevitable, and the time scale is one of decades.

In this review I shall focus on only a small part of the problem but one which may be of particular interest to scien­tists and engineers concerned with local air quality. My aim will be to draw attention to the observed trends in some of the more important trace gases and to say something about the measurement techniques, the accuracy and precision involved, and the present understand­ing of sources and sinks for the atmos­pheric distributioa

DISCUSSION

Radiatively Important Trace Gases Dickinson and Cicerone(4) have shown the way in which the relative con­tributions of various trace gases to the thermal balance of the atmosphere can be assessed. This is done by calculating the partial trapping of outgoing (ther­mal) radiation by radiatively absorbing molecules. This trapping helps to in­crease near-surface temperatures by several tens of degrees Celsius above what they would be if those molecules were not present Taking a reasonable prediction scenario for the likely levels of trace gases in the year 2030, Ram-anathan et al (5) have calculated the relative contribution to the total near-surface temperature increase of 2.1 degrees C. of each of the significant trace gases (Figure 1).

Fig. 1. Cumulative near-surface air warming for an adopted trace gas scenario (From ref. 5). Period: 50 years from 1980 levels. Note: These results are based on a one-dimensional radiative-convective modeL. Full general cir­culation models of the atmosphere which are approximately double these but with lower values at low latitudes and higher values at high latitudes.

Clean Air/August 1986 Vol. 20/3 73

In this review I shall discuss only five of the more important of these 'green­house' gases : carbon dioxide (C0 2) , methane (CH4), Freon-11 (CC13F) and the closely associated Freon-12 (CC12F2), and nitrous oxide (N 20); and also, because of its special role, methyl chloroform (CH3CC13).

The Global Observing Network

In the early 1970's the United Nations Environment Program and the world Meteorological Organization encouraged the establishment of a global network of background air pollution stations. This was in clear recognition of the possible long term consequences of changes in the composition of the atmosphere. For many years the five principal stations in the network were: Barrow (Alaska), Mauna Loa (Hawaii), Samoa, Cape Grim (Tasmania) and the South Pole. More recently, however, other stations have been set up which complete the global coverage (Figure 2).

With one notable exception, all the following trend diagrams are based on data obtained from the Cape Grim sta­tion or from, aircraft derived samples over S.E. Australia. It has been clearly shown that the Cape Grim concen­trations are representative of the Southern Hemisphere- as one might expect since these trace gas lifetimes are generally in excess of 10 years and Cape Grim is well away from the major Northern Hemisphere sources (6, 7). Also, the Cape Grim trends are very similar to those observed throughout the global network.

QMLY C02

CONCENTRATES

Fig. 3. Daily C02 concentrations measured at Mauna Loa, Hawaii Units: ppmv (parts per 108 by volume). DataofC.D. Keeling, available at the C02 Information Center, Oak Ridge, Tennessee, USA.

Carbon Dioxide

So much has been written about this atmospheric trace gas that only the briefest of summaries is included here.

C0 2 is the major'green-house' gas, and a doubling of the 1970 concen­trations has been calculated to increase global near-surface temperatures by about 3 degrees C.

The standard technique of measure­ment is by means of a non-dispersive infra-red gas analyser but this is, in

Fig. 2. The global network of Baseline Stations measuring trace gas concentrations.

principle, only a relative measurement which requires careful calibration with well-defined standard gases (8). A pre­cision of aboutO. 1 ppmv and an accuracy of about 0.3 ppmv is obtained. Another technique is by means of gas chroma­tography and flame ionisation detec­tion but, while this enables much smaller samples of air to be analysed, its preci­sion is not as good as that of the infra­red gas analyser.

The trend curve based on daily sur face measurements at Mauna Loa sta­tion (Figure 3) is reproduced here because it can be regarded as represent­ing the classic set of C 0 2 data It shows, with beautiful precision, not only the secular trend but also the detail of the asymmetric saw-tooth annual cycle with its subtle variation of amplitude.

The measurements shown in Figure 4 are from flask samples from aircraft in the middle troposphere over S. E. Aus­tralia. The distance from the primary annual biospheric exchange in the Nor­thern Hemisphere and the modulations imposed by the Southern Hemispheric biospheric and oceanic exchanges remove much of the annual regularity. But, as with data from all other stations in the global network, a steady increase of about0.4% per year(or approximately 1.3 ppmv/year) can be seen, with levels in 1986 reaching about 345 ppmv(10 -6). This increase has been shown fairly conclusively (9,10) to be due almost entirely to the burning of fossil fuels, currently at the rate of 5 xlO12 kg/year, approximately half of which remains in the atmosphere.

Methane

Methane (CH4) is measured using gas

chromatography and flame ionization detection. The gases in an air sample are separated on a gas chromatographic column and the effluent is fed into a hydrogen flame; ions are produced which are then detected. The precision of this technique is about 1 ppbv with an accuracy of better than 10 ppbv.

Fig. 4. Average monthly values of carbon diox­ide measured in flask samples from aircraft flying at mid-tropospheric levels over S.E. Australia. Units: ppmv(parts per l06 by volume). An updated version of Pearman and Beards-more (Ref. 20).

The concentrations at Cape Grim (Figure 5) are rising by about 1.3% per year, with 1986 levels reaching 1600 ppbv( 10—9). These increases have been attributed(7) to a growth in the amount of CH4 released into the atmosphere.

Fig. 5. Average monthly near-surface values measured at Cape Grim, Tasmania ol; a) methane (CH4)and b) nitrous oxide (N20). Units: ppbv (parts per 109 by volume. Updated ver­sions of Fraser et al (Refs. 7 and 12).1

74 Clean Air/August 1986 Vol. 20/3

Most of this increase is due to a growth in agriculture, particularly rice paddies and ruminant animals, although some is the result also of an increase in min­ing, fossil fuel burning and biomass burning. Contrary to earlier views, ter­mites are thought to be only a minor source (11); natural sources are largely confined to the wet lands (tropical swamps and tundra).

CH4 is not only a significant,'green­house' gas, it is also important in wider aspects of atmospheric chemistry be­cause it is a major sink for the radical OH in the troposphere, which in turn is vital to many chemical reactions. CH4 and CH3 CCI3 observations (see below) at Cape Grim, together with current global release estimates for CH4, have been used by Fraser et al(7) to deduce the levels and seasonal variation of OH in the Southern Hemisphere.

Nitrous Oxide

Another biogenic gas measured at Cape Grim is nitrous oxide(N20). Again the measurement technique uses a gas chromatograph to separate the gases in an air sample but this time the effluent air is fed into an electron field and the resulting ions are measured using an electron capture detector. The preci­sion is about 1 ppbv and the accuracy about 5 ppbv.

These N 2 0 concentrations (Figure 5) are also rising but slowly, at the rate of aboutO.3% per year, with 1986 levels reaching313 ppbv(10 - 9) . It is difficult to determine which of the variations superimposed upon the overall trend are due to instrumental errors and which are real (12).

N 2 0 is derived from soils by de-nitrification processes, and its major sink is in the stratosphere where it is photolysed and reacts with atomic oxy­gen. The current growth in concentra­tion is due to the increased use of nitrogen fertilizers in agriculture and to fossil fuel burning. Currently about 2xl01° kg/year is released into the atmosphere.

N 2 0 is another'green-house' gas but it is important also because it is the major source of stratospheric nitrogen species involved in the catalytic control of ozone levels.

The remaining gases discussed here have no significant natural source: they are man-made.

Freon-11

As with N 2 0 , the Freon-11 (CCI3F) measurement technique involves gas

chromatography with electron capture detection. The precision is about 1 pptv and the accuracy 5 pptv. The Cape Grim concentrations (Figure 6) show an increase of 5 percent per year, with 1986 levels reaching 225 pptv(lO-1 2) . The effect of improved instrumentation in 1978 in reducing the noise level can be seen clearly.

Freon-1 1 and the closely related Freon-12 are used in industry as aerosol propellants, refrigerants, solvents and foam plastic blowing agents. Up to 1984 the rate of increase at Cape Grim, as elsewhere, had slowed down significan­tly since the late 1970's following the legislation in the United States which eliminated Freon-11 as a propellant there. However, increased releases from non-propellant uses have halted this declining rate of increase in global con­centrations. Current release rates are about 3 xl0 8 kg/year for Freon-11 and 4xlQ8 kg/year for Freon-12. The at­mospheric lifetimes for these gases are approximately 70 years and 120 years respectively (13, 14). Both are very efficient'green-house' gases. The major sink for both is by stratospheric photolysis, releasing reactive chlorine which is calculated to significantly decrease stratospheric ozone.

Methyl Chloroform

Methyl chloroform( CH3 CCI 3) is not a strong'green-house' gas but it is inter­esting both for its rapid rate of increase and its role in atmospheric chemistry generally. Again the measurement technique involves gas chromatography with electron capture detection, with a precision of 1 pptv and an absolute accuracy of 10 pptv.

The Cape Grim concentrations of CH3 CCI3 (Figure6) show an increase of 80% since measurements began in 1978; 1986 levels reaching 115 pptv (1012).

This gas is widely used in industry as a solvent (for degreasing, paints, etc.) and, as with Freon-11 and Freon-12, the rapid growth in release rates had ceased; rates in the early 1980's being fairly constant at 5xl0 8 kg/year(7).

While making some contribution to stratospheric chlorine levels, CH3 CCI3 is interesting because, unlike the Freons, its major sink is in the troposphere, involving reaction with the OH radical. The clear annual cycle in Figure 6 has been attributed by Fraser et al (7) to variations in seasonal OH concen­trations (summer maxima, winter min­ima) but as yet no direct, precise method has been devised to measure OH and so to confirm these deductions.

Air Bubbles In See Cores

Past levels of CO2 detected in air trapped in ice were first published last year(15, 16). But more recently, improved tech niques have enabled evidence to be ob tained of changing concentrations o C0 2 , N 2 0 , and CH4 from air bubbles in Antarctic ice cores (17). These new techniques involve dry extraction of air trapped between ice crystals. This is preferable to wet extraction because two uncertainties are associated with melting the ice: first, C 0 2 is soluble in water, and second, the polar nature of the C 0 2 molecule means it preferen­tially attaches to ice crystals and is collected via melting in addition to C 0 2 present in trapped air.

° CHjCCI, pptv

TOO - J * ^

80 V - / * * 6 0 . . •

1976 1978 1980 1S82 1984 191

Fig. 6. Average monthly near surface valu< measured at Cape Grim, Tasmania of: t Freon-U (CC13F) andb) methyl chlorofon (CH3CCI3). Units: pptv (parts per 10" I volume). An updated version of Fraser et ; (Ref. 12).

These latest results (Figure 7) con firm the earlier estimates of fairly cons tant COz levels in the 17th and 18th centuries of around 280 ppmv, and a large release of about5xl01 3 kg of car-bon into the atmosphere since 1850 Other evidence(9, 10) shows this to b almost entirely due to fossil fuel burr ing, with little if any contribution du to deforestation.

Unfortunately CH4 measurements of early samples using dry extractio require correction because metal to metal grinding was found to release spuriou CH4 After correction, however, the CH4 concentrations also show fairly constant levels in the 17th and 18th centuries, around 800 ppbv, with most of the increase having occurred since 1850. (Note that in Figure 7 the earlier values need correction downward- see Legend). Further samples extracted over the last month or so without metal to metal grinding confirm these result.

Clean Air/August 1986 Vol. 20/3

Most of this increase is due to a growth in agriculture, particularly rice paddies and ruminant animals, although some is the result also of an increase in min­ing, fossil fuel burning and biomass burning. Contrary to earlier views, ter­mites are thought to be only a minor source(11); natural sources are largely confined to the wet lands (tropical swamps and tundra).

CH4 is not only a significant,'green­house' gas, it is also important in wider aspects of atmospheric chemistry be­cause it is a major sink for the radical OH in the troposphere, which in turn is vital to many chemical reactions. CH4

and CH3 CCI3 observations (see below) at Cape Grim, together with current global release estimates forCH4, have been used by Fraser et al(7) to deduce the levels and seasonal variation of OH in the Southern Hemisphere.

Nitrous Oxide

Another biogenic gas measured at Cape Grim is nitrous oxide (N 2 0) . Again the measurement technique uses a gas chromatograph to separate the gases in an air sample but this time the effluent air is fed into an electron field and the resulting ions are measured using an electron capture detector. The preci­sion is about 1 ppbv and the accuracy about 5 ppbv.

These N 2 0 concentrations (Figure 5) are also rising but slowly, at the rate of aboutO.3% per year, with 1986 levels reaching313 ppbv( 10 - 9) . It is difficult to determine which of the variations superimposed upon the overall trend are due to instrumental errors and which are real (12).

N 2 0 is derived from soils by de-nitrification processes, and its major sink is in the stratosphere where it is photolysed and reacts with atomic oxy­gen. The current growth in concentra­tion is due to the increased use of nitrogen fertilizers in agriculture and to fossil fuel burning. Currently about 2xl0 1 0 kg/year is released into the atmosphere.

N 2 0 is another 'green-house, gas but it is important also because it is the major source of stratospheric nitrogen species involved in the catalytic control of ozone levels.

The remaining gases discussed here have no significant natural source: they are man-made.

Freon-11

As with N 2 0 , the Freon-11 (CCI3F) measurement technique involves gas

chromatography with electron capture detection. The precision is about 1 pptv and the accuracy 5 pptv. The Cape Grim concentrations (Figure 6) show an increase of 5 percent per year, with 1986 levels reaching225 pptv(I0—12). The effect of improved instrumentation in 1978 in reducing the noise level can be seen clearly.

Freon-11 and the closely related Freon-12 are used in industry as aerosol propellants, refrigerants, solvents and foam plastic blowing agents. Up to 1984 the rate of increase at Cape Grim, as elsewhere, had slowed down significan­tly since the late 1970's following the legislation in the United States which eliminated Freon-11 as a propellant there. However, increased releases from non-propellant uses have halted this declining rate of increase in global con­centrations. Current release rates are about 3xl08 kg/year for Freon-11 and 4x108 kg/year for Freon-12. The at­mospheric lifetimes for these gases are approximately 70 years and 120 years respectively (13, 14). Both are very efficient 'green-house' gases. The major sink for both is by stratospheric photolysis, releasing reactive chlorine which is calculated to significantly decrease stratospheric ozone.

Methyl Chloroform

Methyl chloroform(CH3 CCI3) is not a strong 'green-house' gas but it is inter­esting both for its rapid rate of increase and its role in atmospheric chemistry generally. Again the measurement technique involves gas chromatography with electron capture detection, with a precision of 1 pptv and an absolute accuracy of 10 pptv.

The Cape Grim concentrations of CH3 CCI3 (Figure6) show an increase of 80% since measurements began in 1978; 1986 levels reaching 115 pptv (1012).

This gas is widely used in industry as a solvent (for degreasing, paints, etc.) and, as with Freon-11 and Freon-12, the rapid growth in release rates had ceased; rates in the early 1980's being fairly constant at 5x108 kg/ year (7).

While making some contribution to stratospheric chlorine levels, CH3 CCI3 is interesting because, unlike the Freons, its major sink is in the troposphere, involving reaction with the OH radical. The clear annual cycle in Figure 6 has been attributed by Fraser et a.l(7) to variations in seasonal OH concen­trations (summer maxima, winter min­ima) but as yet no direct, precise method has been devised to measure OH and so to confirm these deductions.

Air Bubbles In Ice Cores

Past levels of C0 2 detected in air trapped in ice were first published last year(15, 16). But more recently, improved tech­niques have enabled evidence to be ob­tained of changing concentrations of C0 2 , N 2 0 , and CH4 from air bubbles in Antarctic ice cores (17). These new techniques involve dry extraction of air trapped between ice crystals. This is preferable to wet extraction because two uncertainties are associated with melting the ice: first, C 0 2 is soluble in water; and second, the polar nature of the C 0 2 molecule means it preferen­tially attaches to ice crystals and is collected via melting in addition to C 0 2 present in trapped air.

Fig. 6. Average monthly near-surface values measured at Cape Grim, Tasmania of: a) Freon-11 (CC13F) and b) methyl chloroform (CH3CCI3). Units: pptv (parts per 1012 by volume). An updated version of Fraser et al (Ref. 12).

These latest results (Figure 7) con­firm the earlier estimates of fairly cons­tant COz levels in the 17 th and 18 th centuries of around 280 ppmv, and a large release of about 5x1013 kg of car­bon into the atmosphere since 1850. Other evidence (9,10) shows this to be almost entirely due to fossil fuel burn­ing, with little if any contribution due to deforestatioa

Unfortunately CH4 measurements of early samples using dry extraction require correction because metal to metal grinding was found to release spurious CH4. After correction, however, the CH4 concentrations also show fairly constant levels in the 17 th and 18 th centuries, around 800 ppbv, with most of the increase having occurred since 1850. (Note that in Figure 7 the earlier values need correction downward - see Legend). Further samples extracted over the last month or so without meta! to metal grinding confirm these results.

Clean Air/August 1986 Vol. 20/3

75

The inference is that the recent increase has been due to expanding agriculture and .partly to the use of fossil fuels, but possibly also it has been due to a reduc­tion in tropospheric OK levels caused by the industrual release of carbon monoxide (18).

The really new results are, however, the clear evidence that only a smail increase in N2 O (about 8%) has occurred since 1600. Again the relatively recent occurrence of even this small rise is consistent with releases due to expand­ing anthropogenic combustion processes.

MEAN GAS AGE ( Year A.D. )

Fig. 7. Historical record of atmospheric N 2 0 , CH4 and C 0 2 concentrations based on measurements of air trapped in the BHD ice core from Law Dome, Ant-aitt\c&(Ref. / 7). Short solid lines rep­resent modern data. Open symbols represent data from other ice core studies, a) N 2 0 . Dashed line based on model results of Weiss (Ref. 21). b) CH4 . Asterisks denote measurements corrected for metal- metal friction. Solid dots require correction downwards by ~400 ppbv in 17 th and 18 th centuries decreasing to negligible amounts for modern samples. Dotted line based on model results of Khali) and Ras-mussen(7?e/ 18). c) C0 2 . Dashed line based on backward extrapolation from modern measurements by Pearman and Beardsmore (Ref.20).

CONCLUSION

It has become a cliche to say that we live in a changing world. But this ex­pression usually refers to changing human attitudes: mores and ambitions. Atmos­pheric scientists have now produced overwhelming evidence that relatively

rapid change is characteristic also of the global atmospheric environment. The background trace gas levels in our atmosphere are increasing; significan­tly and inevitably. There is little we can reasonably do to prevent this happen­ing. Our only recourse is the one that affects all life: adapt or suffer the conse­quences. It is an axiom of rational behaviour that planned adaption is pre­ferable to decisions made' on the run' in response to forced change. The results of changes discussed here are not necessarily mostly for the worse. Op­portunities for exploitation will undoubtedly arise. But for rational plann­ing to commence, even from the point of view of contingency exercises, the first thing required is the attainment of above a critical level of confidence in the pre­dictions. Recent reductions in some of the scientific uncertainties means that this level of confidence has already been achieved in estimates of the future levels of the more important trace gas con­stituents. The same is true for some of the elements of consequential climatic change — and vegetation response to higher levels of C0 2 (19). The time may have come to begin to plan for the socio-economic consequences.

R E F E R E N C E S

1. U.S. Department of Energy, "Detecting the climatic effects of increasing carbon dioxide", U.S. DepL of Energy, DOE/ER-0235, Washington, D. C, December 1985.

2. B R U C E , I P . , "Villach 1985": Con­ference Statement from the UNEP/WMO/ IC SU International Assessment of the Role of Carbon Dioxide and of other Green­house Gases in Climate Variations and Associated Impacts." IK CO^/Climate Report, Issue86-1, Climate Program Office, Atmospheric Environment Service, Ontario, Canada (1986).

3. U.S . Depar tment of Energy, "Direc t effects of increasing carbon dioxide on vegetation", U.S. DepL of Energy, DOE/ ER-0238, Washington, D.C., December 1985.

4. D I C K I N S O N , R E . and F.J. CICER­O N E , "Future global warming from at­mospheric trace gases". Nature, 319, 109-115. (1985).

5. RAMANATHAN, V., RJ . CICERONE, H.B. S I N G H and J.T. KIEHL, "Trace gas trends and their potential role in climatic change", J. Geophys Res. D, 90 5547-5566. (1985).

6. F R A S E R , P.J., G.I. PEARMAN and P. H Y S O N , "The global distribution of atmospheric carbon dioxide, II: A review of provisional background observations, 1978-1980" , / . Geophys. Res. C, 88, 3591-3598. (1983).

7 F R A S E R , P.J., P. HYSON, RA RAS-M U S S E N , A J . C R A W F O R D and M A . K . K H A L I L , "Methane, carbon monoxide and methyl chloroform in the Southern Hemisphere", /. Atmos Chem., 4, 3-42. (1986).

8. PEARMAN, G. I . , " Further studies of the comparibility of baseline atmospheric car­bon dioxide measurements", Tellus, 29, 171-181. (1977).

9. PEARMAN, G.I. and P. HYSON, "Global transport and inter-reservoir ex­change of carbon dioxide with particular reference to stable isotopic distributions", J. Atmos. Chem., 4, 81-124. (1986).

iO. FRANCEY, R.J., "Cape Grim isotope measurements - a preliminary assess­ment", J. Atmos. Chem, 3, 247-260. (1985).

11. FRASER, P.J., R.A RASMUSSEN, J .W.CREFFIELD,J .R . FRENCH, and M.A.K. KHALIL, "Termites and global methane •- another assessment", J. Atmos. Chem., 4, in press.

12. FRASER.P.J., N.DEREK, R O'BRIEN, R S H E P H E R D , R .A RASMUSSEN, A J . C R A W F O R D and L P . STEELE, "Intercomparison of halocarbon and nit­rous oxide measurements, 1976-1984", Baseline 1983-1984, Department of Science, Canberra in press.

13. C U N N O L D , D.M., R G . PRINN, RA RASMUSSEN, P.G. SIMMONDS, F.N. ALYEA C.A CARDELINO, AJ . CRAWFORD, P.J. FRASER and R D . ROSEN, "The Atmospheric Lifetime Ex­periment i. Lifetime methodology and aj> plication to three years o!'CCl3F data",/. Geophvs. Res. C 88, 8379-8400. (1983).

14. C U N N O L D , D.M., R G . PRINN, R.A RASMUSSEN, P.J. SIMMONDS, F.N. ALYEA C.A C A R D E L I N O and A J . CRAWFORD. "The Atmospheric Lifetime Experiment 4. Results for CC12F2 based on three years of data",/. Geophys Res. C, 88, 8401-8414. (1983).

15. N E F T E L A , E . M O O R , H . O E S C H G E R and B. STAUFFER," Evidence from polar ice cores for the increase in atmospheric COj in the past two centuries". Nature, 315, 45-47. (1985).

16. RAYNAUD, D. and J.M. BARNOLA " An Antarctic ice core reveals atmospheric C 0 2 variations over the past few cen­turies". Nature, 315, 309-311. (1985).

17. PEARMAN, G.I., D. ETHERIDGE,F . de SILVA and P.J. FRASER, "Evidence of changing concentrations of atmospheric C 0 2 , N 2 0 and CHU from air bubbles in Antarctic ice", Nature, 320, 248-250. (1986).

18. KHALIL, M.A.K. and RA RAS­MUSSEN, "Causes of increasing atmos­pheric methane: depletion of hydroxyl radicals and the rise of emissions", Atmos Environ., 19, 397-407. (1985).

19. U. S. Department of Energy, "The poten­tial climatic effects of increasing carbon dioxide", U. S. DepL of Energy, DOE/ER-0237, Washington, D.C., December 1985.

20. PEARMAN, G.I. and D.J. BEARDS-MORE, "Atmospheric carbon dioxide measurements in the Australian region: Ten years of aircraft data", Tellus, 36B, 1-24. (1984).

21. WEISS, R F . "The temporal and spatial distribution of tropospheric nitrous oxide", /. Geophys.Res. Q 86, 7185-7195. (1981).

This publication is available in microform from University Microfilms International. Call tuU-frei! 80fl-52i:iO44. Or mail inquiry I": University Microfilms International, 3tX) North Zed) Road. Ann Arlwr. MI 4B106.

76 Clean Air/August 1986 Vol. 20/3

Congress Keynote Address

REDUCING AIR POLLUTION: AN ECONOMICALLY SOUND

INVESTMENT?

Dr. I.M. Torrens

Dr. Torrens is currently Head of the Pollution Control Division of the OECD Environment Directorate, which is res­ponsible for OECD work in the areas of air and water pollution, energy and environment, and hazardous waste management. Prior to this, he worked in the International Energy Agency of the OECD on oil market and energy forecasting questions. He has a Ph.D. in physics from the University of Cambridge.

SUMMARY

The paper begins by a review of the current international policy debate on reducing air pollution, setting it in the historical perspective and explaining the positions of different countries and groups of countries. Since the cost of reducing air pollution is a major factor in the debate, the paper goes on to sum­marise what is known about the costs of reducing emissions of major air pollut­ants from both stationary and mobile sources. Finally, it examines the im­plications of these costs for the policy choices facing governments.

1 THE AIR AS A RESOURCE

Australia is a country rich in natural resources — solid, liquid, and gaseous. Participants to this Congress do not need to be reminded that air is a resource essential to human beings and to the rest of the living environment It is at once the least expensive, the most vital, and the least tangible of the world's natural resources. Title to it cannot be bestowed or claimed, and no person or country can control access to it The air as a free good, however, presents some

*The opinions expressed in this paper are those of the author and do not necessarily represent the views of the OECD or of the governments of its Member countries.

disadvantages. Because it has no listed price, neither does the deterioration in its quality occasioned by its use. Like all resources, its use can bring large economic benefits, but excessive use or abuse can be damaging, even though its absorptive capacity is great It has shown itself capable of absorbing a great deal of the gaseous wastes produced by our industrial society. But it has also demon­strated that it does not have unlimited capacity to absorb these gases and still perform its vital life-supporting role vis-a-vis human and other forms of liv­ing organism.

Much work has been addressed to the quality of the air we breathe and to what levels of pollutants are damaging to human health. Only recently have we begun to address the question of the air quality needed to maintain an environ­ment which is healthy for the ecosys­tem as a whole as well as for our own health and our future economic develop­ment (which is itself dependent on the health of the ecosystem). We are find­ing that some parts of this environment may be more sensitive than human beings are to current levels of man-made air pollution from human activ­ities. The man-made environment, also, can suffer accelerated deterioration through exposure to polluted air.

The OECD, as an international or­ganisation whose main concern is fo-cussed on the economic policies of its Member countries, naturally approaches the issue of air pollution from the ec­onomic perspective. Where, you may ask, does economics enter the picture, given that there is not, nor can there be, a price for pure air? Although we may not pay a direct user charge, there is a price to pay for polluting the air, just as there is one to pay to maintain its quality. The price we pay for polluting the air is the cost of the damage to the environ­ment, both the living and the man- made parts of it The price we pay to maintain air quality — a much more easily mon-etisable price, unfortunately — is the

cost of the air pollution control measures introduced for the most part by govern­ments. If we feel we cannot afford the latter, we shall in any event have to pay the former.

Though there are significant uncer­tainties in both the cost of environmen­tal damage and the cost of preventing it, the former may well turn out in the long run to be significantly larger than the latter. In particular, this paper will try to demonstrate that the cost of a signifi­cant reduction in air pollution is usually not economically crippling, and that in a number of instances, this reduction can even be achieved at a cost which is actually negative, because energy and economic benefits are achieved at the same time as environmental benefits.

But first, why all the recent intense international interest in air pollution? Australia's geographic isolation, not always an advantage, does have the benefit of reducing its transfrontier air pollution problems essentially to zero and making the air pollution fuss in the Northern Hemisphere seem rather re­mote. But since this is a World Con­gress, and since I have been asked to introduce an international perspective, I shall try to give you a brief explana­tion of why air pollution is on the agenda of international meetings of not only Environment Ministers of O E C D but recently Heads of State and Govern­ment of major industrialised countries.

The short explanation, which hides a great deal, is two words long — "Acid Rain".

II THE ACID RAIN STORY

"Acidity is caused almost entirely by sulfuric acid, which may come from coal or the oxidation of sulfur com­pounds from decomposition, but it may also be caused in manufacturing towns by other acids, and in country places to a small extent by nitric acid and by acids from combustion of wood, peat, turf, etc."

This quotation, taken from a book by R.A. Smith, General Inspector of Alkali Works for the British Government, published 1872 (1), shows that acid­ification of the environment is not a new concern. Smith observed that where nun contained more than 40 parts per million of sulfuric acid it prevented the growth of vegetation, damaged buildings, rusted metals, rotted blinds and faded colours in prints and dyed goods. Though he was concerned with local pollution and unaware of the long-range effects of acidic compounds transported by the atmosphere, his study is surprisingly topical given present day concerns in

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many countries about the effects of acid rain and air pollution generally.

Today, the sources of the air pollu-tion, and the proportions of different pollutants emitted, are somewhat dif­ferent taller chimneys have ensured that these pollutants travel greater dis­tances before returning to earth; dif­ferent living patterns and environmental protection measures taken to combat pollution have reduced some of the damage observed by Smith. But new concerns have arisen; new types of damage, especially through long-range transport of pollutants, have come to the fore; the ubiquitous motor vehicle has emerged as a major source of pollu­tion; and the problem has moved into the international arena

The term "acid rain" held little meaning outside the Scandinavian countries, until the past decade. Its political prominence grew over a rela­tively few years to a point where it is now an issue for the attention of the highest levels of government in many countries, particularly in Europe and North America

Why this sudden fame — or infamy? the explanation is quite complex but has to do principally with the fact that acid rain has important transfrontier effects, and therefore international pol­itical implications; and with the fairly recent discovery during the first half of the present decade of severe and ac­celerating damage to the forests of cen­tral Europe.

Acid rain and related air pollution problems now obtain regular news media coverage; they provide the cen­tral themes for many scientific and economic conferences and meetings and are an important component of innumer­able others. They are also on the politi­cal agenda whenever environment ministers come together in various in­ternational fora like the OECD in June last year. They received the attention of the heads of government of the Euro­pean Community and of the seven major industrialised countries' economic sum­mit meeting held in Bonn in May 1985.

There are indications that acid rain will continue to occupy a prominent position on the political agenda of the regions principally affected, and that it may well come to greater prominence in some countries and regions where awareness of the air pollution pro-blematique is still at an earlier stage in its evolution — among these the newly industrialising regions of the world

Acid rain is only one component of a wider set of environmental problems which owe their origin, in whole or in part, to the range of air pollutants emit­

ted by various industrial or other eco­nomic activities. The more correct term for acid rain is acid deposition, which includes both wet and dry forms. But in order to understand better the effects of acid deposition, and to take measures to remedy them, we need to widen our horizons still further to consider air pollution more generally, since some of the effects seem to be related to the quality of the airshed rather than to par­ticular substances which are deposited in a specific place.

The major air pollutants implicated in the types of phenomenon attributed in whole or in part to acid deposition are

sulfur oxides (SOx), mainly sulfur diox­ide (S02); nitrogen oxides (NOx); hyd­rocarbons (HC) or volatile organic compounds (VOC); and particulate matter (PM). These pollutants are emitted in various proportions from both stationary sources and vehicles.

The pollutants emitted are subject to interaction with each other and with other atmospheric substances. For example, atmospheric ozone — one of a range of photochemical oxidants — is formed by interaction of NOx and HC in the presence of sunlight, causes photo­chemical smog, and has been implicated in damage to plants and trees. Atmos-

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pheric pollutants can travel consider­able distances (up to and sometimes more than a thousand kilometres) de­pending on the conditions of their emis­sion and on ciimatic factors. Thus acid deposition in any one location may be the result of emissions over a very large area, especially if averaged over a lengthy time period.

More recently, another pollutant, ammonium (NH4), has been implicated by some scientists in the types of damage attributed to acid deposition, par­ticularly to vegetation. An important source of this is both animal husbandry and excessive use of fertilisers in inten­sive agriculture.

Because of the range of sources and the complexities of the atmospheric processes and the effects following deposition, any strategies to address the problems of air pollution need to be developed with the objective of cover­ing all sources of these multiple pollut­ants — both stationary and mobile.

I l l AIR POLLUTION TRENDS AND SOURCES

The OECD has recently issued a new report on the State of the Environment together with a C ompendium of E nv iron-mental Information for OECD coun­tries on a comparable basis (2). This Compendium contains in particular some detailed information on trends in emissions of sulfur and nitrogen oxides in OECD countries since 1970. Figure 1, extracted from the Compendium, illustrates the trends in sulfur and nit­rogen oxide emissions in two major European countries, the Federal Re­public of Germany and France, com­paring them with Japan, an OECD country which has taken severe regu­latory action to reduce air pollutant emissions over the past decade.

All major industrialised countries have achieved some degree of decoupl­ing of fossil fuel consumption from economic growth since the large increase of oil prices occurred in 1973. The cur­ves of Figure 1 show that some degree of further decoupling of emissions of sulfur oxides from total fossil fuel use took place in all three countries depic­ted here over the period since 1970, but that this decoupling was much more pronounced in Japan than in other countries, as a consequence of the very strict environmental standards prom­ulgated in Japan during the early 1970 s. The corresponding curves for nitrogen oxides show that for the two European countries (and a number of other indus­trialised countries) the emissions of

NOx have stayed in line with, or even grown somewhat relative to total fossil fuel requirements. In Japan, once again as a consequence of a vigorous control programme, nitrogen oxide emissions have been significantly reduced rela­tive to fossil fuel consumption.

These are of course total national emissions. In orderto develop strategies to reduce them it is necessary to have a breakdown among the principal sources. Energy production, conversion and use account for the bulk of emissions of SOx

and NOx. The principal sources — power plants, major industrial install­ations, residential/commercial buildings

and motor vehicles have already been mentioned Considerable variation exists in the relative contributions of the dif­ferent sources to total emissions in dif­ferent countries, as Figure 2 shows, taking SOx and NOx emissions in France, Sweden and the United Kingdom as an example. For example, the contribu­tion of power plants to total national SOx emissions ranges from 10 percent in Sweden to 63 percent in the United Kingdom As for NOx emissions, veh­icles are the principal contributors in most European countries, though not in the United Kingdom, again due to a substantial contribution by power

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7 9

plants. Clearly, the relative contributions of

different sectors to total national emis­sions must be an important factor to consider in deciding upon the most effective strategies to reduce overall emissions.

IV NATURE OF THE POLICY DEBATE

The international policy debate revolves around the implications of scientific uncertainty and the economic impacts of taking action or not doing so. The principal uncertainty lies in the quan­tification of the damage to the various parts of the environment which can be attributed to a given amount of acid deposition or a given exposure to air pollutants. This is the so-called "dose-response problem". The degree of un­certainty varies according to complexity of the phenomena involved, being greater in the case of forest damage than for •acidification of water bodies, for ex­ample.

And if there is uncertainty as to what has happened in the past or what is hap­pening at present in the form of damage, there is even greater uncertainty about the future. One of the most critical fac­tors is whether or not the damage is cumulative. Is what we observe now the true extent of the effects of past and pre­sent levels of air pollution on the en­vironment, or is latent damage ac­cumulating in other regions and to a greater extent than is presently recog­nised? For example, does the discovery of declines in growth of some tree species in Eastern North America foreshadow the same type of forest damage which has been found in extensive areas of Europe?

The policy debate in industrialised countries therefore centres on whether it would be wiser to take action prom­ptly by establishing stricter emission controls on acidic gases, or to wait until scientific research produces more evid­ence of actual or impending damage. The principal arguments of those who advocate delay in further policy action are: — taking action now requires substan­

tial expenditure which may later be demonstrated by research to have been unnecessary;

— less costly methods and technologies for emission control may be developed within the next decade. The principal argument for rapid

action, in addition of course to the actual damage already sustained, is the need to reduce present and future damage.

In particular, the danger that some of the ecosystem effects could prove to be accumulative and virtually irreversible is of particular concern. Also, pro­ponents of rapid action point out that even after passage of stricter control measures, the unavoidable delay in their implementation means that reduc­tions in emissions consequent on these measures will only begin to occur several years later— for example, it takes some three years to design and build a flue gas desulfurisation plant, and more than a decade to renew an automobile popula-tioa A third argument for rapid action comes from the time which scientific experts estimate may be necessary for research to provide answers to some of the most significant questions. In the United States this has been estimated to be several years for effects on aquatic ecosystems and a decade or longer for forest effects.

In theory, of course, it should be possible to base policy decisions on the best estimate of the costs versus the benefits of specific actions to reduce air pollution. But the scientific uncertainty mentioned at the beginning of this sec­tion makes cost-benefit analysis of limited value in determining appropriate levels of control of air pollutant emissions. An OECD study (3) on the costs and bene­fits of sulfur oxide control, published in 1981, concluded that while there seemed to be a broad balance between costs and benefits up to quite high levels of emission control, the range of uncer­tainty of the benefits(or environmental damage costs) in money terms was extremely large — much too great to permit policymakers to zero in on any particular level of control. The large amount of cost-benefit analysis which has followed this work, mainly in the United States and Europe, still runs up against the same problem (4,5).

Consequently, policymakers are faced with a three-way choice: can we afford to wait for the results of further research and assessment; should we on the other hand insist on substantial reductions in emissions using best available control technologies; or should we at least take out some type of insurance policy in the form of a carefully designed pro­gramme aimed at a point where the cost-effectiveness curve turns sharply upward?

To make such a policy decision re­quires at least some reliable informa­tion on the technological state of the art and on the costs of emission control (and on the trends of these costs). It also requires an objective look at what the acceptance of these costs may mean for the national economy.

What can be done to control the emissions leading to air pollution and acid deposition and what does it cost? The OECD has in recent years pro­duced a number of reports which pro­vide cost data(6-8), and we are currently engaged in a study of costs and cost-effectiveness of air pollution control for both stationary and mobile sources, with particular emphasis on nitrogen oxides and hydrocarbons.

This paper highlights some of the results of work by OECD and other organisations and individuals on the costs of controlling air pollution, and raises some questions regarding what these results might signify for policy­making in this field, in the context des­cribed above.

V THE COSTS OF REDUC­ING EMISSIONS

Any discussion of this must be prefaced by stressing the contribution which has been and can still be made by changing patterns of energy production, conver­sion and use. The large energy price increases of the past decade have stim­ulated measures to increase efficiency and reduce waste in all sectors of energy use. The recent declines in oil prices may affect this process, certainly at the margin, but technological advances are unlikely to be reversed, and more aggregate energy efficiency gains are still in the pipeline as, for example, the building stock is renewed over the decades to come. Less total energy per unit GDP means less air pollution, and the environmental benefits can and should be considered on a par with the energy and economic benefits of in­creased energy efficiency as a reason for maintaining an emphasis on this line of policy in the future. The inclusion of the environmental argument becomes especially relevant even in the event of a continued decline in the real price of energy.

VA Stationary Installations: Electricity Generation

The cost of reducing emissions of sulfur oxides (SOx) and nitrogen oxides (NOx) is usually an important compo­nent of debates within countries and internationally on how far to limit air pollution from power plants. This is not without reason: in Japan for example, which has exercised the most stringent emission requirements for utilities, the cost of air pollution controls can occupy up to 20 or 25 percent of the total capi­tal cost of a new coal-fired power plant, or about 15 to 20 percent of total elec-

80 Clean Air/August 1986 Vol. 20 /3

trie generating costs of the plant But, when we look more closely at SOx and NOx control cost estimates, par­ticularly making international com­parisons, we have found that estimates for seemingly similar systems can differ markedly between countries or organ­isations, sometimes by a factor of 2 to 3 or more. Obviously, this adds to the controversy that exists surrounding what are likely to be the costs of pro­posed regulations.

In this context, the OECD has re­cently undertaken work to explore more rigorously the reasons why cost estimates for air pollution abatement differ so much between countries and organis­ations, even for control equipment with similar capabi l i t ies^ . We examined specific estimates, provided with sub­stantial supporting data, by represen­tatives of the Umweldbundesamt( UBA) in Germany, the Electric Power De­velopment Company (EPDC) in Japan, and the Electric Power Research In­stitute (EPPJ) in the USA. Data were supplied for flue gas desulfurisation (FGD), selective catalytic reduction (SCR) of NOx, and electrostatic pre­cipitation of particulate matter, applied to hypothetical coal-fired power plants in these three countries. Without mak­ing any adjustments to the estimates submitted, the apparent costs differed markedly from country to country, as Table 1 including FGD and SCR shows.

A careful analysis of the different factors reveals that a part of the cost variation arises from different approaches to the configuration of the F G D sys­tems in the United States as compared to elsewhere. Early difficulties with FGD reliability combined with regu­latory requirements led the United States utilities to develop modular designs including spare capacity. Typi­cally, a 600 MW power generating unit would use 4 x 150 MW F G D units plus one spare unit(i.e. 20 percent redun­dancy). In Europe and Japan, on the other hand, the practice adopted has been to build one single FGD unit cap­able of handling the entire flue gas stream, with no or only a token amount of extra capacity. This leads to signifi­cant economies of scale and reductions in construction time (hence interest during construction).

For NOx control using SCR, physi­cal factors affecting the cost estimates include the assumptions for catalyst life, particularly important for annual generating cost estimates. Also, the integration of the three different types of pollution control into a single system produces cost savings in the Japanese

Notes: (1) These estimates are adapted from data from the Umweltbundesamt (UBA) in Germany, the

Electric Power Development Company (EPDC) in Japan; and the Electric Power Research Institute in the USA. These numbers are preliminary and subject to change. They are based on power plants of different sizes (gross capacity of 350 MW for UBA; 1000 MW x 2 for EPDC, and 545 MW for EPRI), with capacity factors varying between 60-70 percent, and fuel qualities of roughly comparable heat content, sulfur content, and nitrogen content, but large differences in ash content Reported costs converted to US currency using August 1985 exchange rates of 2.8 DM/$. Japanese costs reported in US dollars. Individual cost items are normalised on net plant capacity.

(2) (3) (4) Source: " Understanding Pollution Abatement Cost Estimates" OECD Environment Monograph

No. 1 (OECD 1986). This reference contains a complete description of the equipment and assumptions underlying these cost estimates.

case. Among the methodological factors

found to be most important are the assumed inflation rates used to calcu­late levelised annual costs. For exam­ple, an assumption of 8.5 percent inflation over a 30-year system lifetime pro­duces a levelised cost 1.5-2.5 times greater than the first-year cost Another large source of difference between the estimates may be that market currency exchange rates often do not accurately reflect the purchasing power of those currencies in their own countries. Also, differences in the handling of uncer­tainty in the cost estimates can explain a significant portion of the discrepan­cies between the figures.

This type of comparison illustrates the pitfalls facing those who would draw policy conclusions from such cost esti­mates, but at the same time, by making the reasons for differences among such estimates, clearer— introducing a higher degree of transparency into this field— it serves to remove an element of confu­sion from the policy debate. The objective of this OECD report was not to judge the relative merits of different pollution control systems or methods of cost estimation. Rather it was to indicate what are the critical parameters which cost estimators should make explicit if

the results of their work are to be under­standable, comparable with other esti­mates, and of value to policymakers.

Flue gas desulfurisation is relatively speaking the most costly of the pollu­tion control technologies normally applied. However, it is useful to dif­ferentiate low, medium, and high sulfur fuel, for which different methods of desulfurisation are most cost-effective. For a new low sulfur coal-fired power plant a dry desulfurisation process is the least expensive, achieving some 70 percent sulfur removal. If the coal is medium sulfur a spray-dry or "wet-dry" process may be more cost-effective. For high-sulfur coal the wet processes, throwaway or regenerative, are the most effective in terms of cost per tonne of sulfur removed, though by necessity they are more expensive per kilowatt hour of electricity generated because of the fuel sulfur content and because of additional technological requirements to ensure reliability.

V B Stationary Installations: Aggregate Pollution Control Costs

Overall estimates have been made for

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81

the costs of control strategies for SO, and NO, in Europe and the United States (4, 5, 9-13). These include the installation of pollution control equip­ment on both new and existing power plants and major industrial installations. Table 2 gives an order of magnitude. The numbers shown here are of course large— of the order of billions of dollars over a period of a decade or so. But we should try to get them into the perspec­tive of what they would mean for the electricity consumer. For example:

• In the German case, the emission reduction of SO, and NOx together, when blended into the power genera­tion and distribution system, are estimated to add about one pfennig per kilowatt/hour to the electricity price to consumers (or approx­imately 6 percent) (9).

® The United Kingdom Centra! Elec­tricity Generating Board has esti­mated that retrofitting FGD to existing coal-fired power plants to achieve a 50 percent reduction in SO, emissions might add, over a period of more than a decade, about 5-6 percent in total to the average cost of electricity generated in the United Kingdom, and considerably less than this to consumers' elec­tricity bills (10, 11);

« A recent report issued in the United States places the average electricity generating cost increase nationwide caused by a 10 million ton annual reduction in S0 2 emissions from power plants at about 3-4 percent (though some utilities might incur cost increases several times this high, since they have a large proportion of older more polluting plants) (5).

Increases of this magnitude are not negligible, but they are far from catas­trophic. Because of the time which would be required to realise a pro­gramme of emission reduction, the electricity price increase would be spread out over a decade or so.

VC Reduction of Vehicle Emissions

Mobile sources are major sources of NOx and VOC, and therefore must be an integral part of strategies aimed at reducing acid deposition or ozone. However, the problems associated with estimating the costs of pollution control applied to vehicles are generally even more complex than for stationary sour­ces. Annual operation and main­tenance costs (or savings) tend to be

(1) 1982 prices. (2) Includes retrofitting F G D on 70% of large coal and lignite boilers over 25 MW. (3) 1984 prices. (4) 1983 prices. Includes cost of replacement of output capacity lost through retrofitting of FGD. This

accounts for about 25% of total capital costs of £1990 million sterling.

TABLE 3 Indicative NO, and VOC control costs and effectiveness

for gasoline Automobiles (1982 US Dollars)

1. Assumes 3.1 g/km VOC and 2.8 g/km NO x as emission baseline, which is about equivalent to current European gasoline automobiles.

2. Assumes 5% real discount rate; catalysts amortized over 5 years, all other equipment over 10 years.

3. Savings in maintenance of $4 per year in all cases where unleaded gasoline is used 4. Includes $7 as extra annual cost of unleaded gasoline (high-side estimate), this approximately

equals .5 c/litre. In some countries unleaded gasoline is less expensive to consumers than the leaded varity due to tax incentives.

substantially greater than annualised capital amortisation costs. Plausible changes in the assumptions can cause large changes in the calculated cost-effectiveness numbers, in some cases

meaning the difference between net savings and net costs for the same emis­sion control technology. Table 3 con­tains a very approximative estimate of the costs and cost effectiveness of NOx

82 Clean Air/August 1986 Vol. 20/3

and VOC control for automobiles. Where emission reductions are achieved through specific add-on equipment, like the three-way catalytic converter to control NOx, HC and CO, the cost situation may at first glance seem re­latively clear. The equipment itself costs some $ 100-275 per car according to most current data. However, the three-way catalytic converter necessi­tates certain electronic controls to monitor and adjust fuel use. Once added, manufac urers use these electronics to optimise engine performance, fuel con­sumption, and emission control under a variety of driving conditions. The total cost, including these associated mod­ifications to the propulsion system, then rises to approximately $300-500 per car. It is difficult to assess how much additional cost to attribute to the gradual improvement in vehicle energy/environ­ment performance, and particularly how much of this cost should be allocated to pollution reduction It would probably be unfair to ascribe all the costs of elec­tronic controls to pollution abatement when they incur a range of other benefits as well.

Another complication in the analysis involves the switch to unleaded gas­oline required by catalytic converters. Lead is a poison and there is increasing consensus on the health hazards due to emissions from motor vehicles burning leaded gasoline, particularly in densely populated urban areas. But quite apart from the human health aspect, lead in gasoline can be corrosive and abrasive to engines. So there are substantial benefits in using only unleaded fuel. In fact, an important study prepared by the Australian Environment Council in 1980 reviewed previous research in North America and concluded that the maintenance savings to vehicles from fewer engine tune-ups, spark plug changes, oil changes, and exhaust sys­tem replacements could add up to hun­dreds of millions of Australian dollars per year (74). More recently, the US Environmental Protection Agency car­ried out a new cost/benefit study which confirmed that such savings in auto­mobile maintenance charges plus other quantifiable benefits exceed the costs of reducing lead emissions (15). This study was the basis of a decision by EPA to phase down lead in gasoline, and a complete ban is being considered

As an alternative to the catalytic converter, the "lean-burn" engine is now being developed in a number of countries primarily for its fuel economy advantages, but also as a promising way to meet stricter emission standards, especially for smaller cars. It reduces emissions of NOx but not of unburnt

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HC. Particular uncertainty accrues to cost estimates for the lean-burn engine, since it is a technology still under development The estimates in Table 3 indicate that a lean-burn engine would accrue net savings annually to its owner compared to a conventional engine as well as emitting less NOx. Though it may be misleading to say that there are monetary savings per tonne of NOx

reduction since that is not the principal objective of the new engine, it neverthe­less appears to be the most efficient means of achieving that 70-90 percent NOx emission reduction.

If the lean-burn engine is used in association with an oxidation catalyst (simpler than a 3-way one), significant reductions in both NOx and HC could be achieved However, Table 3 indicates that this combination is likely to be economically inferior to the 3-way cata­lyst when all factors are considered. Consequently, reliance on develop­ment of the lean-burn concept to meet pollution control requirements in the future may be a sound bet if only NOx

emissions are to be reduced, but less so if reductions in hydrocarbon emissions are required, as a measure to reduce ozone formation for instance. Research on engine configurations aimed at re­ducing the amount of hydrocarbons entering the exhaust system, if success­ful, would improve the lean-burn engine's competitiveness for overall emission reduction

This type of analysis concerning the true costs of pollution control raises dif­ficult and usually very controversial questions, fundamental for environ­mental policymaking. For example, what is the economically optimum level of emission reduction needed? How soon should such abatement be required? What is the role of environmental regulation in preventing or stimulating research and development of technol­ogies that work better or are more effi­cient while emitting less pollution? How can environmental and energy (or other economic) goals be best pursued in parallel? There is clearly consider­able scope for multi-faceted analyses aimed at throwing greater light on these issues.

VI IS IT REALLY TOO EXPENSIVE TO REDUCE AIR POLLUTION?

Economic considerations are fun­damental to the policy debate dis­cussed in Section IV. Those who argue for postponing action until further re­search is done to reduce uncertainty maintain that spending sums in the

billions of dollars with no assurance of reversing environmental damage does not make economic sense. Those who argue for action feel that they would be buying insurance against accelerating and perhaps irreversible damage, and that the cost of this insurance is not pro­hibitive. They note that some manufac­turing sectors of their economies may even benefit from a pollution control programme.

So where does the expenditure neces­sary to achieve significant reduction in major air pollutant emissions lie on the economically "bearable" scale? Sec­tion V B showed that in most countries a 30-50 percent reduction in sulfur and nitrogen oxide emissions from power plants might add a few percent to con­sumers' electricity bills (usually of the order of 5 percent, but up to 15 percent in the worst hit regions), and this in­crease would be spread out over the period of a decade or so which it would take to implement the programme. This can hardly be expected to have an im­portant impact on the competitiveness of industrial electricity users, or to impoverish private consumers. In fact, over the past decade in most indus­trialised countries, consumers have been faced with far greater annual increases in electricity prices for reasons which have nothing to do with the en­vironment, such as oil price increases or rising coal miners' wages.

Section V C drew attention to the dif­ficulties involved in assessing the cost impact of better pollution control in vehicles. Add-on equipment like a catalytic converter may increase the cost of an automobile by 5 percent or so, depending on its size and category — a percentage which is comparable to that of some other features like a talking dashboard whose benefits may not always be so evident At the same time, research aimed at producing more economical and less polluting vehicles is continually improving their fuel economy and thus reducing the total annual cost to consumers. There is evidence that with better pollution con­trol, maintenance costs for the vehicle over its lifetime are also reduced (es­pecially in the case where unleaded gasoline is used as a fuel). Thus the net cost/benefit picture to the car owner is unclear, and he or she could end up with net benefits, in the form of energy savings and lower maintenance, even when the possible benefits to the environment are not factored into the equatioa

VII DEALING WITH UNCERTAINTY IN POLICYMAKING: THE CASE OF FOREST DAMAGE

Section IV described the nature of the policy debate. Given that the driving force in this debate, in Central Europe at least, is forest damage, it is useful to consider what implications uncertainty in this field holds for policy making.

Research work on forest damage has resulted in a number of alternative ex­planations for observed damage, which may be enumerated as:

(1) Foliage damage by gaseous pollut­ants;

(2) Root damage by heavy metals mobilised by soil acidification;

(3) Drought;

(4) Air pollution-related increased sus­ceptibility to general stresses like climate, insects and diseases;

(5) Leaching of magnesium and calcium frpm forest soils and foliage through acid deposition;

(6) Excess nitrogen resulting from nit­rate deposition leading to unstable growth.

These theories are complex and sets of them are inter-related. Five out of six are connected with air pollution, direc­tly or indirectly. Those which involve soil impoverishment and toxicity (2) and (5) have the potential for perma­nent impairment of forest regenerative capacity (i.e. irreversibility).

Let us look now at the implications of the positions taken by different groups of countries in the light of these forest damage theories. First, the position of those countries who say that action to reduce air pollution further is prema­ture and more research is needed, has several implications:

— It assumes that more research could result in reducing the complexity and multiplicity of suspected causes of forest damage in a reasonable length of time;

— It gives a preponderant weighting to the "drought" theory compared to the other five air pollution-related ones, since only this theory would justify taking no action to reduce air pollution;

— It gives very little credence to — indeed, implicitly rejects — the potential irreversibility inherent in the soil acidification theories.

Looking now at the position of those countries who have taken action to

reduce emissions, whether in response to forest damage or other effects, it becomes clear that their political res­ponse to a situation involving scientific uncertainty is one of risk aversion. By their action they are taking out an in­surance policy which may not only reduce future damage but also the pos­sibility and danger of ecologically ir­reversible developments.

VIII THE POLICY CHOICES

The complexities of the policy choices must be evident from the previous sec­tions. They range from a decision not to take any specific action to reduce air pollution further than present policy dictates, to a decision to require the use of best available technology in both stationary and mobile sources. The policy conundrum is the reconciliation of knowledge, technology and economics, which is rather difficult because all three of these are moving targets. Technol­ogy improves continuously and the cost of pollution control tends to fall as technology develops. Knowledge link­ing pollutant emissions to environmen­tal impacts, though it rarely can provide unambiguous answers to the policy­maker's questions, still responds posi­tively to well-directed research.

The policymaker's instinctive reac­tion when faced with such a situation is usually to wait before taking action. After all, next year we may know more about the effects; or there could be a technological breakthrough in pollu­tion control, saving on aggregate a huge sum of money for the same emission reduction. To take action usually requires a compelling scientific reason, or com­pelling political pressure, or a combina­tion of the two.

But the argument to wait can be logically turned around It is quite con­ceivable that science, technology and economics will always be more in favour of action next year, ad eternuum. That being the case, it may be more pro­pitious — in the face of increasingly convincing scientific evidence (even if partly circumstantial), and given a set of pollution control technologies which are proven, reliable and not financially crippling — to opt for some form of action now, even if a limited and grad­uated form To a greater or lesser degree, a substantial number of OECD coun­tries are now adopting this philosophy and course of action. Investment in en­vironmental protection, whose poten­tial productivity is sometimes questioned a priori, has rarely been called into question a posteriori as providing an inadequate return. Our trees, our fish,

our historic and not-so-historic buildings may not be able to thank us for protec­tion of the quality of the air, but our children are likely to thank us for a more agreeable environment and— to end on a less altruistic note — they may also thank us for making possible a con­tinuation of sustainable economic de­velopment which, it is increasingly recognised, is catalysed by a clean and healthy environment, and limited sooner or later if environmental degradation is allowed to proceed

REFERENCES

1. "Air and Rain: the Beginnings of a Chemi­cal Climatology", A. A. Smith, (Long­man's Green, London 1872).

2. "The State of the Environment 1985" and "OECD Environmental Data: Compen­dium 1985 (OECD, Paris 1985).

3. "The Costs and Benefits of Sulfur Oxide Control'YOJSCA Paris 1981).

4. "AcidRain— A Review of the Phenomenon in the EEC and Europe", Environmental Resources Limited, for the Commission of the European Communities, (Graham and Trotman, Brussels 1983).

5. "An Analysis ofthe Issues Concerning'Acid Rain'", Report to the Congress by the Comptroller General, GAO/RCED-85-13 (1984).

6. "Costs of Coal Pollution Abatement" (OECD, Paris, 1983).

7. Coal and Environmental Protection: Costs and Costing Methods (OECD, Paris 1983).

8. " Understanding Pollution Abatement Cost Estimates", Environment Monograph No. 1, (OECD, Paris 1986).

9. "Ecological and Economic Aspects ofthe Ordinance on Large Firing Installations in the Federal Republic of Germany", paper submitted by the German Government to the OECD Conference on Environment and Economics, June 1984.

10. Royal Commission on Environmental Pol­lution, Tenth Report (HMSO, London 1984).

11. "Acid Rain", Fourth Report of the UK House of Commons Environment Com­mittee, Vol. 1 (HMSO, London 1984).

12. "Analysis ofthe Waxman-Sikorski Sulfur Dioxide Emission Reduction Bill (H. R 35400);" prepared for the US Environ­mental Protection Agency bylCFInc, April 1984.

13. "Acid Deposition Briefing", Electric Power Research Institute, June 16, 1983.

14. "Report on the Development of a Long-Term National Motor Vehicle Emissions Strategy", Committee on Motor Vehicle Emissions for the Australian Transport Advisory Council (Australian Govern­ment Publishing Service, Canberra 1982).

15. "Costs and Benefits of Reducing Lead in Gasoline: Final Regulatory Impact Analysis", USEPA Office of Policy Analysis Report EPA-230-05-85-006 (February 1985).

84 Clean Air/August 1986 Vol. 20 /3

REPORT A V A I L A B L E

25,000 Fabric Filter Installations Listed in New Report

Detailed information on each of 25,000 fabric filter installations in the United States is included in a new report from The Mcllvaine Co. entitled "Fabric Filter Installations in the U.S.". The extensive information is based on data compiled as part of the National Emis­sions Data System. This comprehen­sive report is being made available in easy to use binders and at less cost than available in a printout form from EPA through a special search.

Each fabric filter installation is listed in alphabetical order by State and then by Country. For each installation the company name and address, efficiency, amount of particulate emitted, as well as sulfur and nitrogen oxides and car­bon monoxide emissions are included. Also listed are primary collectors such as centrifugal collectors where they are acting in conjunction with the final fab­ric filter.

The temperature at the fabric filter is indentified as low, medium or high. The application is identified by standard industrial classification (SIC) number. The process and the specific emitting equipment such as grinder, furnace, kiln, etc. are also given. Important parameters such as raw material or fuel type are provided.

The 10 states with the largest num­ber of listed fabric filters are as follows:

State 1. New Jersey 2. Illinois 3. Tennessee 4. Iowa 5. Georgia 6. Ohio 7. Indiana 8. Minnesota 9. Wisconsin

10. Alabama

Number 3563 2744 2450 1876 1197 1176 1120 1043 980 847

Substantial numbers of installations are in the following industries: non-ferrous primary smelting, non-ferrous secondary smelting, iron foundries, steel mills, asphalt paving, concrete and cement Many chemical, mining and food installations are also identified.

The 3,700 page report is contained in 5 large 3 ring binders and is available for $395. Individual state sections are available for the first State and $25 for each additional State.

For more information on "Fabric Filter Installations in the U.S." contact The Mcllvaine Company, 2970 Maria Avenue, Northbrook, II60062 U.S.A. 312-272-0010.

Clean Air/August 1986 Vol. 20/3

85

Liabilities 1984

478 Australian Capital Territory 62570 Federal

677 Journal 1418 New South Wales 2750 New Zealand 4690 Queensland

321 South Australia

1985 395.29

74806.08 555.62

15601.97 5613.58 7566.01

628.49

1984

15000 36181

5000 12610

1008

Assets

Federal Deposits Esanda Debentures AGC Ltd. Compound Debentures Commonwealth Savings Bonds Westpac investment Account Westpac 7 th Internat. Congress A/c Westpac Bonus Deposit Account

1985

7828.20 5000.00

22089.38

38000.00 $72917.58 3834

772 2312

424 3815

(121) 2863

(50)

83 (14184)

(2876) (307) (322) 266

2301 (8081) 3815

South Australian Conference Victoria & Tasmania Victorian Conference Western Australia Federal Deposit- New Zealand Excess Income over Expenditure Journal New Zealand Western Australia Excess Expenditure over Income Australian Capital Territory New South Wales Queensland South Australia South Australian Conference Victoria & Tasmania Victorian & Tasmania Conference Federal New Zealand Federal Deposit

_ 506.34

11.74 373.67

_

175.34 2093.43

214.56

156.52 2477.20 4308.71

189.09 -

270.48 11.74

783.54 _

$106058.69

2483.33

(8197.28)

3000

--

357

7686 (2457)

395 5007

556 15602

385 4566

628 506

12 17

Queensland Branch Commonwealth Trading Bank IBD New South Wales Branch Esanda Ltd. Debenture Westpac Deposit Western Australian Branch Perth Building Society New Zealand Branch Westpac Bank I.B.D. Less Provision for Currency

Fluctuation Bank & Cash on Hand Australian Capital Territory Federal Journal New South Wales New Zealand Queensland South Australia Victoria & Tasmania Victorian & Tasmanian Conference Western Australia

1000.00 6086.87

8666.26 2457.40

238.77 1104.96 730.96

6037.90 1498.15 1257.30 439.40 235.86

206.55

2000.00

7086.87

381.68

6208.86

11749.85

106059 $100344.84 106059 $100344.84

19TH ANNUAL REPORT

FOR THE YEAR ENDED DECEMBER 3 1 , 1985

For most members of our Society the main change for the year 1985 was to receive a larger journal. The Council had decided that as the journal was the principal connection with the majority of our members it needed to become a stronger link. This was an expensive step, but as essentail one. Our untiring editor, Hanns Hartmann, introduced new aspects to the journal in response to your wishes expressed through sur­veys and also negotiated a new printing contract and a new printer. In addition to that demanding job Hanns has also been editing the Proceedings for the 7 th World Clean Air Congress, a formid­able task.

Len Ferrari and Alisdair Guthrie, assisted by an able band of enthusiastic and knowledgeable speakers continued to develop the air pollution courses on measurement and control. These cour­ses now appear set to become a perma­nent service offered by the Society.

Outside the limelight, a 50 strong team of society officers guided us through a year of meetings, lectures, plant visits, workshops and SAA representatioa Without their dedication the Society could not function. Thanks to all their efforts the Society is in a sound finan­cial position as reflected in the attached accounts.

Should we be satisfied with this situation?

I believe not I believe that if our Society does not continue to grow, to exert a dynamic influence in our com­munity it can lose the momentum which

has been developed over the past 20 years.

What should be done to maintain our momentum? Members should become more involved, should actively seek new members, should look for new view points, and ideas. We should seek new issues to argue and from those debates, forge new considered opinions to give to governments, industry and the public.

We need to continue to expand our interest in indoor air quality including the issue of smoking indoors, to sift the facts on acid rain and even nuclear winter.

What part will you play in ensuring the future of the Society as a construc­tive member of our Australian com­munity?

K M. SULLIVAN P R E S I D E N T

86 Clean Air/August 1986 Vol. 20 /3

CLEAN AIR SOCIETY OF AUSTRALIA & NEW ZEALAND CONSOLIDATED BALANCE SHEET

AS AT 31 st DECEMBER 1985,

1984 905 162 30

15250 80

15251 5383 (642) 3661

219 3435

512 1447 368

49615 20710

2063 21989

140438

Expenditure

Audit fees Bank Fees Insurance Journal Expenses Legal Fees Meeting & Conference Expenses Postages & Stationery Provision for Fluctuation of N. Z. Currency 7th International Congress Expenses Repairs & Renewals Secretarial Scholarships & Prizes Subscriptions Sundry Expenditure Society Ties Victorian & Tasmanian Conference Expenses Air Pollution Measurement Courses Air Pollution Training Courses Excess Income over Expenditure

1985

1295.00 122.24 420.54

16841.71 -

9393.75 3590.69

-. 18879.68

_ 4922.27

116.00 1140.57 616.75

2076.00 -

18184.91 2816.65

-

80416.76

1984

18725 8688 7680

395 10200

10 47027

9554

623 37536

140438

Income

Members' Subscriptions Interest Journal Income Sale of Proceedings Meeting & Conference Income Donations Victorian & Tasmanian Conference Victorian & Tasmanian Conference

Donations Sundry Income Air Pollution Measurement Course Excess Expenditure over Income

1985 20292.54 17415.91 6152.71

741.65 4302.00

---

378.00 25420.00

5713.95

80416.76

AUDIT REPORT

I have audited the Consolidated Balance Sheet of the Clean Air Society of Australia & New Zealand for the year ended 31 st December 1985. Subject to the audited and unaudited statements from the various branches the Balance Sheet represents a

true and fair view of the Society's affairs as at 31st December 1985.

K.S. Basden (Hon. Treasurer)

Dated 2nd May 1986

R H. Lound A.A.S.A., C.P.A., A.C.I.S.

Public Accountant Registered under the Public Accountants

Registration Act 1945 as amended

NEW PRODUCTS

New Australian System for Asbestos Safety:

An Australian-developed process for eliminating asbestos health risks from buildings has just been released.

The system was introduced by the N.S.W. Shadow Minister for Transport, Dr Terry Metherell, at a conference at the Institution of Engineers attended by a group of building owners, architects, and engineers. Its operation was ex­plained by the managing director of Ecologel Pty. Ltd., developer of the concept, which has formed a joint ven­ture with a marketing company Air Quality Control Pty. Ltd, to service the Australian market

Tradenamed "Fiberguard", the sys­

tem is a unique means of continuous removal of all dust contamination from the air content of a building. It consists of a special electronic air purifying unit which captures the dust in a fluid reser­voir instead of on conventional metal plates. This eliminates any re-emission of captured dust via impact, vibration, etc. In the case of asbestos particles, any risk of such re-emission is unac­ceptable.

Safe disposal of accumulated det­ritus is provided by accredited agents for the system in all States. On users' premises this involves only a quick exchange of Fiberguard cells for pre-cleaned units, with laden cells then removed under controlled safety con­ditions to a properly equipped work­shop.

The concept offers immediate com­plete safety for occupants of asbestos-insulated buildings, pending contracts

for actual removal of the asbestos con­taining material. All airborne particles are captured with a recycling effeciency over 98 per cent in properly-installed systems. There are additional health benefits in the removal of smoke and other contaminants also. The capture fluid also has a sterilising action against hazardous bio-cultures such as Legion­naires' Disease, and is free of dangerous ozone generatioa

The system was invented by civil ergineer Ron Hansen, 61, following the death of a close relative from lung disease some years ago. Mr Hansen's business associates in America will be launching the Fiberguard system there also.

Further information is available from: Ecologel Pty. Ltd, 4 Jonathon Place, Frenchs Forest, N.S. W. 2086 Telephone: (02) 452 2750. Telex AA27702 (and interstate distributors).

Clean Air/August 1986 Vol. 20/3

8 7

CLEAN AIR SOCIETY OF AUSTRALIA & NEW ZEALAND STATEMENT OF INCOME & EXPENDITURE FOR YEAR ENDED 31 st DECEMBER 1985.

88 Clean Air/August 1.986 Vol. 20/3

CHEMICAL COMPOSITION OF RAINWATER AT NEW PLYMOUTH,

N.Z., IN 1981-82.

G.P. Ayers, R.W. Gillett and U. Cernot

The authors are working in the C.S.I.R.O. Division of Atmospheric Research Dr. G.P. Ayers is a Prin­cipal Research Scientist, Mr. R Gillet is an Experimental Scientist and Mr. U. Cernot is a Technical Officer.

ABSTRACT

Rainwater from 38 individual pre­cipitation events was collected at the coastal site of New Plymouth, New Zealand, during the 12 month period from September 1981, for the purpose of establishing the acidity of rainwater at a relatively unpolluted site in the southern midlatitudes. pH values were mostly between 5 and 6, the volume weighted mean from all samples, measured approximately one week after collection, being 5.57. For 31 samples pH had also been measured at the collection site immediately after collection: it was found that the pH measured one week later, at the time of complete chemical analysis, averaged 0.2 pH units higher than those made at the time of collectioa This observation is consistent with suggestions made elsewhere that weak, biologically labile organic acids can make significant con­tributions to rainwater acidity.

Excess sulfate plus nitrate concen­trations were low, as anticipated, and exceeded ammonium concentration plus residual alkalinity from sea salt aerosol by about 10 μeq/L, on average. If nit­rate and sulfate entered the rainwater primarily as the respective acids then pH values close to 5 should have resulted unless there was an additional, balanc­ing source of alkalinity. Soil dust con­taining calcium carbonate apparently provided that source.

INTRODUCTION

The composition and chemistry of the atmosphere in places remote from urban/ industrial areas has received increasing attention in recent times as it has become clear that human activities are modify­ing atmospheric composition over all space scales, from local, to regional, to global. On the one hand studies of

remote areas contribute a valuable 'reference' perspective, on how the atmosphere behaves chemically in a more or less unperturbed state. On the other hand such studies also serve to define the global spread of anthropogenic influences on the distribution and chemistry of particular elements or chemical species.

Clouds and rain play a number of important roles in the overall scheme of atmospheric chemical processes. They modulate the solar radiation flux that drives atmospheric photochemistry; vigorous convective clouds can provide a unique transport mechanism by which species of surface origin may be rapidly transported high into the mid-troposphere; the liquid water phase provided by clouds acts as a chemical reactor for some soluble species enabling aqueous phase reactions to occur at many times the rate of comparable gas phase reactions

- it also promotes some reactions that do not occur in the gas phase; and most importantly, precipitation acts as the primary process by which a wide range of chemical species is finally removed from the atmosphere. Indeed it is the incorporation of sulfuric and nitric acids of anthropogenic origin into rainwater that consititutes a modern phenomenon of considerable concern in the more heavily industrialised regions of the world - the phenomenon of "acidic rain".

In the Australian region there is a distinct lack of data on rainwater acidity and composition in both urban/industrial regions and in relatively unpolluted regions. Only two studies on rainwater acidity in populated regions at Aus­tralia have been reported, one for the Sydney metropolitan area(1), the other for the region around Newcastle, N. S.W. (2). No studies using comparable "wet-only" rainwater collection methods have addressed the question as to the "natural" levels of rainwater acidity typical for similar southern latitudes. The few studies that have been per­formed generally were motivated by agricultural concerns and usually in­volved monthly sampling in which both rainwater and dustfall were collected. However, the results obtained must

have a bias towards soil dust, rather than rainwater composition, so a clear picture of rainwater composition may not have emerged in these cases. The work described in this paper was under­taken specifically to provide a set of data on the acidity of rain at a southern mid-latitude site in the absence of large anthropogenic sources of acidity.

SCOPE OF THE STUDY

Rainwater was collected on an event basis at the coastal site of New Plymouth, New Zealand (39°03'S, 174°04'W) for a 12 month period from September 1981. This site was favoured because it is at a latitude comparable with that of the Australian Baseline Air Pollution Station, at Cape Grim(40°41oS, 144° 41'E). The collector was physically located 2 m above ground level, 5 m from the Meteorological Office at New Plymouth airport, 10km northeast of the township. The Meteorological Office is situated about 500m inland from the coastline, the intervening land being almost flat, covered with grass and occasional patches of gorse. Local topography is dominated by Mt Egmont, a symmetrical volcanic cone of almost 300m, located 40km to the southeast The collector used was a polyethylene funnel of 20.3 cm maximum diameter, draining directly into a polyethylene collection bottle of 0.6 L capacity. The collector was triple-rinsed with dis­tilled, de-ionised water and exposed just prior to the onset of each rainwater event, and was retrieved within one hour after the event pH was measured immediately on one aliquot of sample, following which the sample on a second 100 ml aliquot of it was transferred to a polyethylene storage bottle and mailed to the Division's Sydney laboratory, where it was usually received within 5 days and was stored in the dark at 2C C until analysis.

At the Sydney laboratory the sam­ples were analysed for pH (Activon BJ 9210 combination electrode); conduc­tivity (PTI model 10), ammonia (3); sodium, potassium, magnesium and calcium (standard flame atomic ab­sorption methods); and chloride, nit­rate and sulfate (standard ion chro­matography methods) (4). Analysis of replicate samples indicated that, at 95 per cent confidence, analytical im­precision did not exceed ~ 10% for the ion concentrations and conductivity or ~ 0.03 pH units for pH. A total of 38 events was sampled during the 12 month period.

As an aid to interpretation of the chemical data three additional para­meters were recorded continuously

Clean Air/August 1986 Vol. 20/3

89

throughout the observational period. These were surface wind (direction and speed), Aitken nucleus concentration and radon concentration data supplied by E. K. Bigg). At a coastal site such as New Plymouth these parameters are usually very good indicators of the extent to which sampled air masses are principally maritime in character or have had recent contact with land (5). However in the present case attempts to use these parameters to classify the rain events sampled into maritime and continental categories were unsuccessful The radon data in particular suggested that while tending mostly towards maritime, the air masses sampled were noticably mixed in character. For reasons not worth developing here we suspect that to a large extent this mixed charac­ter resulted from the dominance of Mt Egmont over local topography, causing some recycling of air masses involved in upslope/downslope flows on a diur­nal cycle. Unfortunately this indication of somewhat confused local meteorol-

' ogy precludes us from further discus­sion of air mass origins, as had been our intention. Nevertheless we can report that during rainwater collection periods Aitken nucleus concentration was never high enough to indicate that the air mass sampled contained emissions from the city of New Plymouth

DATA QUALITY

Of the 38 samples 33 contained suffi­cient volume for the complete set of chemical analyses. The first step in checking data quality involved calcula­tion of the total cation and anion sums for the 33 samples. In three cases the cation- anion sums showed an imbalance of more than 20 per cent, indicating suspect data The second step involved calculating enrichment factors relative to seawater composition for the four metal ions, chloride and sulfate. En­richment factor E, of ion i, relative to reference ion j is defined as

where the subscript sw or sw and rain refers to seawater and rain composition respectively. Since sodium, magnesium and choloride are generally thought to undergo no enrichment at the air/sea interface during formation of sea-salt aerosol (6 ) enrichment factors for each of the six ions were calculated with sodium, magnesium and chloride refer­ences in turn. Seawater ratios were taken from the compilation of Millero

(7). Intercomparison of enrichment fac­

tors for each ion in each sample using

the three different reference ions and comparison of each enrichment factor with those from all other samples using the same reference ion revealed one anomalous calcium concentration (en­riched by a factor of 20), two anolmalous magnesium concentrations (enriched by factors of 0.1, and 0.3), and eleven samples in which potassium was anomalously enriched (factors ranging from 4.3 to 151) often in conjunction with a small chloride enrichment (in 8 of the 11 cases chloride was enriched by> 25%. While the one or two calcium and magnesium anomalies could be accepted as isolated analytical mis­haps, the more numerous and apparen­tly coupled potassium and chloride excesses suggest a more systematic contamination of samples. Our belief now is that the contaminated samples received at the Sydney laboratory were those aliquots that had been used for on-site pH determination, so receiving KC1 contamination from the elec­trode, rather than separate aliquots of the collected samples as specified in the site instructions.

In the cases of ammonium and nit­rate ions no anomalous values were evi­dent in the data records, since in neither case did any individual value fall out side the range of geometric mean ± 2 c calculated from all data for each ion.

The discussions that follow specifi­cally exclude from consideration all entries in the data record that have been identified as suspect This leaves 24 samples for which all ion concen­trations are specified and 14 samples for which some concentration data, mostly for potassium and chloride, are missing.

RESULTS AND DISCUSSION

1. Sea salt aerosol components

Volume-weighted and geometric mean ion concentrations derived from the 24

samples having complete data records are shown in Table 1. Both means are given since both are commonly used in the literature.

Also shown are calculated concen­trations for sodium, potassium, mag­nesium, calcium, chloride and sulfate, these being the major ionic constituents of seawater. The calculated values are to be compared with the geometric means and are based upon two as­sumptions that are generally accepted-the first is that the ionic composition of ocean surface waters (at least for major ionic constituents) is essentially cons­tant world-wide (7); the second is that in the processes of aerosol formation at the ocean surface there is little or no change in relative concentration (no fractionation, or enrichment) of the major ionic species, especially for sodium, chloride and magnesium (6). Thus the calculated values in Table 1 assume no enrichment for magnesium, which is fixed at the observed geomet­ric mean value while the remaining calculated values are based on the appropriate concentration ratios for each ion to magnesium.

Relative to the chosen magnesium reference both the sodium and chloride means shows only minor enrichments (< 10%), sulfate is somewhat more en­riched (~27%) while potassium and calcium show large enrichment (> 100%). Nevertheless it is clear from Table 1 that sea salt components make the dominant contribution to total ionic loading in the rainwater sampled. Furthermore mean ammonium and nit­rate levels of 2-3 μeq/ L and mean excess sulfate level of ~10 μeq/L are consis­tent with a predominantely maritime/ non-urban character at the New Plymouth site, since levels and order of magnitude larger than these values are usually observed at continental sites subject to atmospheric urban/ industrial emissions (8). A similar pattern is shown by data from Amsterdam Island(37° 47'S, 77° 31'E) and from Cape Grim, the only

Table 1: Volume-weighted and geometric means: ion concentrations in μeq/L. Rainfall in mm. The values calculated for comparison with the geometric means assume seawater ionic ratios and no magnesium enrichment H+N refers to pH measurements made in New Plymouth, H+s

to measurements made about 1 week later in Sydney.

90 Clean Air/August 1986 Vol. 20/3

comparable southern hemisphere sites for which we are aware of published data on "wet only" rainwater composi­tion (9,10).

2. Continental aerosol components

At a near-coastal site such as New Plymouth, somewhat removed from extensive urban/industrial areas, the major continental contribution to pre­cipitation composition is likely to be from the incorporation of soil-derived aerosols into clouds and raia As in seawater, the main cationic species to be found in soil dust and soil organic material (plant debris, etc) are sodium, potassium, magnesium and calcium. However compared with seawater, plant/soil material is apparently enriched in potassium and calcium relative to sodium and magnesium (7/,), the en­richments increasing with distance from the coast (12). This picture is consis­tent with the mean values shown in Table 1, where the major ionic enrich­ments relative to magnesium as the seawater reference ion are indeed shown by potassium and calcium.

The picture with regard to anions is not so clear, although chloride, car­bonate or bicarbonate ions are com­monly found in the soluble component of soils. In fact a small chloride enrich­ment is apparent in Table 1, and in a later section a soi'i-derived carbonate/ bicarbonate component is identified.

3. Trace gas and associated aerosoi components

A third component identified elsewhere in precipitation is that from soluble atmospheric trace gases or gas-derived aerosol^13). Major soluble species are gaseous ammonia, nitric acid and sul­fur dioxide, the latter subject in solution to relatively rapid oxidation to sulfate (14). These nitrogen species and sul­fate are ubiquitous components of the "background" aerosol: much of the material is incorporated into cloud at the earliest stage since it is these aerosol particles that provide the necessary pre-existent surface upon which water vapour nucleates to form cloud droplets at small water vapour supersaturations

(13). Although there is very little informa­

tion available on the trace gas and aerosol composition of the atmosphere at coastal or maritime sites in the southern hemisphere, relevant trace gas concen-trations(NH3, S 0 2 a n d H N 0 3 ) of the orderO. 1 ppbv(parts of 109 by volume) appear reasonable, as do aerosol mass

concentrations of 0.5 ptg/m3 (STP) for sulfate andO. 1 jug/m3 (STP) for nitrate (13). In conjunction with typical liquid water contents of precipitating clouds (0.1 —1 g/m3, STP) and a simplified microphysical description of the cloud nucleation and in-cloud scavenging processes these figures lead to predic­ted cloudwater/rainwater concen­trations of the order of a few micro-equivalents per litre for each of ammonia, nitrate and non-sea salt sulfate (13). Reference to Table 1 again indicates that the observed ammonium and nit­rate concentrations and the apparent sulfate enrichment are of this magnitude, as indeed they are in the comparable data from Amsterdam Island (9), and Cape Grim(lO).

4. Observed pH

Until a few years ago the pH of rain­water at relatively unpolluted sites such as New Plymouth often had been dis­cussed in terms of a somewhat mythical pH of 5.6 for "natural" or unpolluted rain, this figure being the value predic­ted for pure water in equilibrium with atmosphere CGfe at 3 30 ppmv and 280 K. Clearly such a simplified picture of acidity in unpolluted rain is unrealistic, since all cloud droplets nucleate on, and thus ingest, soluble aerosol com­ponents while trace gases such as ammonia, nitric acid, sulfur dioxide, formic acid etc, are ubiquitous in the atmosphere, even if at low levels. A more realistic concept is that rainwater acidity at any particular site and any particular time is controlled by the local concentrations and variability of acidic and basic components of the atmospheric aerosol and traces gases. To illustrate this concept Charlson and Rodhc(15) carried out calculations in which only variations in the atmosphere sulfur cycle were considered: predicted pH ranged from4.5 to5.4 depending upon assumed parameter values, but the general con­clusion was that pH values below 5.6 should not be seen as "unnatural", and indeed may be the rule rather than the exception. Recent observations from a number of carefully chosen " unpolluted" locations world-wide lend support to this view (16).

Despite the foregoing discussion Table 1 indicates that the mean pH measured in the laboratory for the New Plymouth samples was in fact close to 5.6 Furthermore the pH frequency dis­tribution shown in Fig. 1 reveals that only 2 of 38 samples had a pH < 5.0. Yet from the values in Table 1 it is apparent that mean excess sulfate plus nitrate exceeds mean ammonia by about

10 jii.eq/L, which would imply a mean pH of 5.0 if sulfate and nitrate entered rainwater as the respective acids neut­ralized only by gaseous ammonia. We must conclude that an added source of alkalinity was present the most likely is soil dust containing calcium carbonate, as evidenced by the calculated calcium excess of ~20 /ieq/L.

5. Statistical Analysis

The foregoing discussions suggest the pH in the rainwater sampled at New Plymouth is controlled by a balance between low levels of nitric and sulfuric acids("background" trace gases/aerosol) and alkalinity derived from low levels of calcium carbonate (continental soil dust). The seasalt aerosol also con­tributes a small amount of alkalinity to the rainwater, however on average this is a minor contribution (~2 jueq/L) compared with the concentration of soil-derived calcium (~20 ju.eq/L). Atmospheric C 0 2 also has a minor buf­fering effect on the acid-base equili­brium.

A simple statistical test of this pic­ture involves calculation of correlation coefficients between the total concen­tration of nitrate plus excess sulfate and, in turn, hydrogen ion, hydrogen ion plus ammonium ion, and hydrogen ion plus ammonium ion plus excess calcium ioa Results are given in Table 2. The suggestion that nitrate and sul­fate acidity is neutralised by atmospheric ammonia and calcium carbonate aerosol is supported by the increase in the magnitude of the correlation coefficient when each of ammonium and excess calcium is included.

Also listed in Table 2 are coef­ficients derived from a least squares fit in which excess calcium concentration is regressed simultaneously against nit­rate, excess chloride, excess sulfate and bicarbonate as independent variables.

1 0 i — i — i — i — i — i — i — i — i — i — i — i

8 -

14

o 1 fc •> L _ , •D

-z. - I—I -0 I — I — i — i — > — i — i — i — I — I — 1 —

4-6 50 54 5-8 62 6-6 pH

Fig. l:pH distribution obtained from New Plymouth rainwater samples, analyses carried out in Sydney.

Clean Air/August 1986 Vol. 20/3

91

Table 2: Results of statistical analyses, concentrations in /ieq/L.

correlations

Bicarbonate concentration was calculated from observed pH assuming equilib­rium with atmospheric C 0 2 at 33 Pa and288 K. That the significance of the individual regression coefficients for nitrate, excess sulfate and bicarbonate exceeds 95 per cent confidence in each case is further strong evidence of the role played by calcium carbonate aerosol in the neutralisation of trace quantities of nitric and sulfuric acids.

The final line in Table 2 contains coefficients obtained from the linear regression of sample H+ concentration measured on-site at New Plymouth against H+ concentration measured approximately 1 week later at the laboratory in Sydney. The fact that the slope is significantly larger than unity points to a slight, but significant loss of free acidity in the samples in the week between collection, and receipt at Syd­ney. This behaviour mirrors that found for rainwater collected at Katherine, in the Northern Territory (17), which was explained as arising from the bac­teriological consumption of hitherto unnoticed weak organic acids in the rainwater samples. Our results thus support the recent contention (17) that traces of weak organic acids are ubi­quitous in the atmosphere but have gone undetected in rainwater because they are rapidly consumed biologically if delays between sample collection and analysis exceed more than a day or so.

CONCLUSION

Data on major ions and pH have been obtained from 38 wet-only rainwater samples collected at New Plymouth, New Zealand in the 12 months to Sep­tember 1982. The major contributors to dissolved ionic species were iden­tified as seasalt, continental soil dust and "background" atmospheric trace gases and aerosols. Rainwater acidity was low, the mean value of pH measured at the point of sample collection being ~5.4. This level of acidity was pro­duced in the main by the balance bet­ween trace quantities of nitric and sulfuric acids (totalling about 10 μeq/L) from the "background" troposphere and trace quantities of calcium car­bonate aerosol derived from continen­tal soil dust

The low levels of nitrate and excess sulfate found were consistent with those reported elsewhere for two other maritime sites located at similar latitudes in the southern hemisphere, and show little evidence of enhancement by anthro­pogenic emissions. Therefore we con­clude that pH values less than 5 are not expected for unpolluted rain at this site.

coefficient

Bo= -0.34

B 1 = 1.45

Finally, a small but significant reduc­tion in hydrogen ion concentration in the collected samples over the week subsequent to collection is consistent with a recent suggestion that biologically labile weak organic acids can con­tribute to rainwater acidity.

ACKNOWLEDGEMENTS

Partial funding for this work was received from the Australian Department of Science as part of the Cape Grim Baseline Air Pollution Station pro­gram. Particular thanks are due to Messrs Monks, Roberts and Crawford at the New Plymouth site for rainwater collection and pH determination We thank Dr. E.K. Bigg for provision of the meteorological, radon and Aitken nucleus data and for useful discussions.

REFERENCES 1. Ayers G. P. and Gillett R. W. Some obser­

vations on the acidity and composition of rainwater in Sydney, Australia, during the summer of 1980-81. J.. Atmos. Chem, 1984. 2, 25.

2. Avery R. A preliminary study of rainwater acidity around Newcastle, NSW. Clean AirAust 1984, 18, 94.

3. Dal Pont G., Hogan M. and Newell B. 1974, Laboratory Techniques in Marine chemistry. IL Determination of ammonia in seawater and the preservation of samples for nitrate analysis, CSIRO Division of Fisheries and Oceanography Report No. 55.

standard error 0.71 0.15

4. Nagoumey S.J. and Bogen D.C. Measure­ment of trace constituents in global baseline precipitation samples. Can. J. Spectrosc, 1978, 23, 101.

5. Ayers G.P. and Gras J.L. The concentra­tion of ammonia in Southern Ocean air, J. Geophys. Res., 1983, 88, 10655.

6. Duce R.A and Hoffman E.J., Chemical fractionation at the air/sea interface. Ann. Rev. Earth Plan ScL, 1976, 4, 187.

7. Millero F.J., The physical chemistry of seawater. Ann. Rev. Earth Plan. Sci, 1974, 2, 101.

8. Miller, J.M., Galloway, J. N. and Likens, G.E. Origin of air masses producing acid rain at Ithaca, New York. G.E., Geophys. Res. Lett, 1978, 5, 757.

9. Galloway J. N. and Gaudry A, The com­position of precipitation on Amsterdam Island, Indian Ocean. Atmos. Environ., 1984, 18, 2649.

10. Baseline Air Monitoring Report 1978, Department of Science and Technology, Australian Government Publishing Ser­vice, Canberra, 1981.

11. Langkamp P.J. and Dalling M.J., Nut­rient cycling in a stand of Acacia holosericea A. Cunn. exG. Don III.Aust J. Bot, 1983, 31., 141.

12. Brasell H.M. and Gilmore D.A., The cation composition of precipitation at far sites infarnorthQucensland.Aust J. EcoL, 1980, 5, 397.

13. Ayers G.P., The chemical composition of precipitation: A southern hemisphere per­spective: In Atmospheric Chemistry, Ed E.D. Golberg, Springer- Verlog Berlin, Heidelberg. New York, 1982.

92 Clean Air/August 1986 Vol. 20/3

14. Penkett S.A., Jones B.M.R., Brice K.A. and Eggletan A.E.J., Atmos. Environ. 1979, 13, 123.

15. Charlson R.J. and Rodhe H., Factors controlling the acidity of natural rainwater. Nature, 1982. 295, 683.

16. Galloway J. N., Likens G.E. and Hawley M.E., Acid precipitation; natural versus anthropegenic components. Science 1984, 226, 829.

17. Keene W.C., Galloway J. N. and Holden Jr. Measurement of weak organic acidity in precipitation from remote areas of the world J.D., J. Geophys. Res. 1983, 88, 5122.

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94 Clean Air/August 1986 Vol. 20 /3

SOILING OF BUILDING MATERIALS ABOUT MELBOURNE— AN EXPOSURE STUDY

by K. G. Martin and A. N. Souprounovich

K G . Martin is Program Leader and A. P. Souprounovich is an Experimen­tal Scientist in the Design for Dura­bility program of the CSIRO Division of Building Research, P.O. Box 56, Highett 3190, Victoria

ABSTRACT

Samples of a number of common build­ing materials; concrete and aluminium both painted and unpainted, and glass, have been exposed horizontally and vertically on racks at sites in the Melbourne metropolitan area and grime accumulation assessed The assess­ment involved measuring the darkening effect of the grime after subjecting the specimens to a standard cleaning pro­cedure. Sites were characterized in terms of freefall dust, water soluble dust, rain­fall, and suspended particulates.

The results indicate that the ranking of specimen behaviour is similar at the different sites but the influence of the sites in terms of the characteristics measured is not straightforward A linear relationship between the water solubles in freefall dust and darkening is found only for painted surfaces and glass and a possible grime accumulation mechan­ism is developed based on this obser-yatioa

The relative performance of the dif­ferent materials and proposals for further work are also discussed

1. INTRODUCTION Although concerned mostly with motor vehicle emissions, a survey of the liter­ature on the damage to building materials by air pollutants in Australia concluded that soiling was a major degradation mechanism requiring further study (1). Following studies in the United States (2,3), the survey indicated that soiling of glass, aluminium window frames, stone, paint, and concrete was likely to be the most costly form of damage caused by air pollution. Most soiling is believed to be associated with chemical

attack upon the substrate promoted by moisture, salts, or organic constituents of the particulates and leading to corro­sion or erosion damage as well. Soiling was reported as a major but little under­stood problem of building facades (4).

In previous outdoor exposure studies, grime has been suspected of ameliorat­ing the effects of sunlight on plastics films(5) and of promoting corrosion of metal specimens in Port Moresby (6). Apart from studies on paints (7), little specific investigation of the attachment of particles to building surfaces has been reported An investigation has therefore been initiated by exposing a selection of materials at different sites in the Melbourne metropolitan area, characterizing the sites, and measuring the effects of grime accumulation.

2. EXPOSURE TRIALS

2.1 Materials The materials exposed were 250 x 200 mm rectangular samples of concrete, painted concrete, aluminium, painted aluminium, and window glass. Six rep­licates of each were exposed three ver­tically and three horizontally, at six sites by mounting on metal racks with

Figure 1 Exposure rack and dustfall collec­tor at site 3.

bolts andneoprene washers as shown in Fig. 1. Specimens were exposed for 12 and 24 months starting from July 1981.

The concrete used ordinary portland cement, the mix being designed to achieve a 28-day strength of 30 M P a Speci­mens were 25 mm thick, cast individ­ually, and wet cured for 7 days, the surfaces being either steel trowelled to a smooth finish or roughened to simu­late 'rough cast*. Following curing and drying, half of the smooth-surfaced concretes were painted with two coats of a white, flat, water-dispersed acrylic as specified by the Standards Associa­tion of Australia (8).

The aluminium was of alloy 5005 series as specified by the Standards Association of Australia (9). The un­painted specimens were 0.8 mm thick and of full-hard temper whereas the painted specimens were from 0.55 mm thick, three-quarters hard-tempered alloy. The paint was a silicone polyes­ter applied by a commercial coil coat­ing process including curing by oven heating. Two colours were used, white and light grey.

The glass was ordinary soda-lime float plate 6 mm thick.

2.2 Material Soiling Assessment

In an earlier study of metals exposed in Melbourne and Papua New Guinea (6), it was found that the mass of grime accumulated could not be determined because of simultaneous corrosion of the substrates. Cleaning off the grime did not restore the substrate and chemi­cal removal of corrosion product and grime was required to determine corro­sion mass loss relative to the unexposed controls. Light reflectance measure­ments on specimens both as retrieved and after washing gave an indication of relative grime accumulation at different sites. This effect of discolouration or darkening of the surface due to grime has also been used by others (7,10) as a. simple measure of soiling. It has been measured in this study by a tristimulus light reflectance meter and reported in terms of a lightness darkness coor­dinate (L) conceived by Adams and calculated according to Glasser and Troy (11). The transparent glass speci­mens were measured against a standard white backing plate. Each specimen was measured before exposure and after exposure both as received and after washing. Washing was done in a stan­dard way by immersion in a tray of water and brushing the surface six times with a brush fixed to a mechanical arm, traversing the surface at a constant

Clean Air/August 1986 Vol. 20/3

95

speed with the bristles of the soft brush set at a fixed interference distance. The washed specimens were allowed to dry before repeating the reflectance mea­surement The back surface of each glass specimen was thoroughly cleaned by scrubbing firstly with water and detergents then alcohol before each measurement so that the grime readings refer only to the outward exposed face. The difference betwen the L values for the 'washed' and 'as received' speci­mens was considered to indicate 're­movable grime' ( L R ) and the difference between the L values for the 'washed' and 'original' specimens to indicate 'fixed grime' ( L F ) .

2.3 Exposure Sites

Six sites were chosen to cover indus­trial, city, inner urban, and outer urban conditions. Co-operation was obtained from the Environment Protection Author­ity of Victoria (EPAV) and the Road Construction Authority of Victoria (RCAV) to use sites where air quality data were being monitored. Table 1 lists the sites and gives coordinates on the Melbourne corrosivity map (12) as well as corrosivity rates.

TABLE 1 Exposure Sites

2.4 Characterization of Sites

Freefall dust was measured at each site by a simple funnel and bottle (as also shown in Fig. 1). Dust on the funnel was washed into the bottle by rain and by a fixed amount of distilled water when collected, then filtered, dried, and weighed each month. The amount of rain water thus collected was recorded and the amount of water solubles or particulates passing through the filter (< 1.6 μm) was determined by evap­orating a portion of the filtrate to dry­ness and weighing. Suspended particu­lates were measured by a high volume

TABLE 2 Grime on Smooth Concrete (SC)

Site

1 Horizontal Vertical

2 Horizontal Vertical

3 Horizontal Vertical

4 Horizontal Vertical

5 Horizontal Vertical

6 Horizontal Vertical

Note: Mean L value for originals = 74.0 LR = L Attributed to removable grime. LF = L Attributed to fixed grime.

D = specimen damaged.

TABLE 3 Grime on Rough Concrete (RC)

Site

1 Horizontal Vertical

2 Horizontal Vertical

3 Horizontal Vertical

4 Horizontal Vertical

5 Horizontal Vertical

6 Horizontal Vertical

Note: Mean L value for originals = 7 1 . 8

TABLE 4 Grime on White Painted Concrete (CPW)

12 months

0.4 0.4

0.5 0.1

1.8 0.4

0.5 0.6

0.3 0.8

4.0 3.6

L R

24 months

3.6 0.4

1.4 0.4

4.6 0.9

0.6 0.6

D D

5.3 4.9

Lp

12 months

1.7 0.2

1.6 0.1

8.2 1.0

2.4 0.1

4.8 1.4

12.9 7.2

24 months

9.3 0.2

3 2.4 1.1

9.8 0.1

4.7 0.5

D D

15.3 9.6

12 months

0.5 0.1

1.7 1.6

0.3 0.5

0.2 0.1

2.1 0.2

3.1 2.1

LR

24 months

2.5 0.2

0.7 0.1

0.7 0.4

!.2 0.6

D D

4.2 3.3

12 months

5.8 !.4

9.7 3.6

5.6 2.5

1.2 1.0

10.8 0.3

12.4 6.5

Lp

24 months

13.5 1.2

13.1 4.1

12.5 3.1

5.4 0.6

D D

16.3 9.3

Site

1 Horizontal Vertical

2 Horizontal Vertical

3 Horizontal Vertical

4 Horizontal Vertical

5 Horizontal Vertical

6 Horizontal Vertical

12 months

1.9 1.3

1.1 0.7

1.6 0.9

1.7 1.0

1.0 1.1

4.9 1.0

24 months

2.8 1.4

1.3 0.5

1.4 0.7

2.0 1.1

D D

7.3 8.4

12 months

3.9 1.5

1.4 0.7

1.4 0.7

0.9 0.1

2.6 0.1

7.7 6.9

24 months

4.4 3.1

1.1 0.7

2.2 1.5

1.6 0.8

D D

10.8 8.6

Note: Mean L for originals = 95.4

sampler drawing the air through a glass fibre filter at 50 L/min. Increase in mass of the filters and change of white­ness (Adams L coordinate) as measured with the tristimulus reflectance meter were recorded after a period of capture of 24 hours. The high volume air sam­pler was moved from site to site to get spot measures of suspended particulates.

3. RESULTS

3.1 Grime on Specimens

Results of the measurements of remov­able and fixed grime for each specimen are given in Tables 2 to 8 for horizontal and vertical specimens after 12 and 24 months exposure at the different sites.

9 6 Clean Air/August 1986 Vol. 20/3

No.

1

2

3

4

5

6

Address3

Bureau of Meteorology Victoria Street, Melbourne

Booth Reserve, Dandenong

Railway Station, Alphington

Mulgrave Freeway, Mulgrave, 19m from freeway

Mulgrave Freeway, Mulgrave, 50m from freeway

Victoria Docks

Corrosion rateb

(μm/y)

16

14

19

12-14

12-14

18

a. 1,2 and 3 were EPAV monitoring sites and 4 and 5 were RCAV monitoring sites.

b. See reference (12).

L R LF

Site LR LF

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

12 months

1.2 0.1

1.6 0.1

1.9 0.7

0.9 0.2

0.9 0.6

0.2 1.2

24 months

0.6 0.3

0.4 0.4

1.0 D

0.8 0.1

D D

2.3 1.5

12 months

9.0 6.5

4.4 2.9

12.3 5.5

4.1 4.2

12.2 10.8

15.7 17.3

24 months

11.6 9.4

10.8 5.3

14.1 D

18.6 16.9

D D

13.1 14.2

Note: Mean L value of originals 42.7

TAELE 6 Grime on White Painted Aluminium (APW)

Site LR LF

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

12 months

0.6 0.8

1.2 0.6

1.0 0.4

0.6 0.6

0.6 0.5

2.4 4.7

24 months

2.4 1.3

1.1 0.3

1.0 0.5

0.7 0.4

D D

3.9 6.8

12 months

3.1 0.7

1.2 0.3

1.1 0.3

0.7 0.6

1.2 0.6

6.9 4.7

24 months

6.5 1.2

1.3 0.6

1.1 0.9

1.7 1.1

D D

13.0 5.7

Note: Mean L value for originals = 83.7

TABLE 7 Grime on Grey Painted Aluminium (APG)

Site L R L F

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

12 months

1.0 0.4

1.0 0.3

0.4 0.4

0.6 0.4

0.3 0.3

2.2 3.7

24 months

1.8 0.3

0.6 0

0.4 0.2

0.4 O.l

D D

3.5 6.0

12 months

2.4 0.6

1.2 0.4

1.1 0.5

1.1 0.5

1.4 0.7

4.2 3.1

24 months

4.6 0.7

1.5 1.1

1.1 0.8

1.1 1.1

D D

8.1 2.6

All specimens were white to grey with­out chromaticity. The colours were therefore described in terms of the Adams L coordinate in which perfect white is 100 and perfect black 0. The L values for replicate specimens were within ± L unit The mean L values for unexposed specimens are given as a note to the tables. The AL values indi­cate the visual contrast of the grime on the exposed specimens compared to the origina. surface and may be compared independently of the original L values (Le. it indicates how much the grime has darkened the surface). In terms of amount of grime, comparisons between specimens in AL units is only valid for specimens of similar original L value. Some further comment on this aspect is given later in relation to the grime collected on white filters in the high volume sampler.

Unfortunately site 5 was damaged by vandals before the 24 month speci­mens were retrieved

3.2 Characterization of Sites The results for the freefall dust at each site are given in Table 9 for the first 12 months of the exposure. Data on water solubles are also given; it may be noted that water solubles constitute a much higher percentage component of the dust when dustfalls are low. The total of water solubles vary much less between sites (a factor of 3) than the total dustfall (a factor of 7). The high dustfalls at sites 1 and 6 are provided mostly by insolubles or coarse dust It is of interest to note that dustfall was highest in early summer (October to December) and lowest in early winter (May to July) in Melbourne.

Table 10 gives the data on rainfall collection. It should be noted that the method used was not standard. Never­theless, the data are in general agree­ment with Bureau of Meteorology records in terms of ranking of sites with respect to average annual rainfalL Sites 2, 4, and 5 are known to receive higher rain­falls than the other more westerly sites. The pattern of monthly rainfall and dustfall do not correlate at any of the sites.

Suspended particulates were only measured at sites 1, 3, and 6. The results are given in Table 11. There is much less variation between sites than fordustfall(Table 9). It is apparent that sites 1 and 3 are very similar, while site 6 has a higher concentration of suspen­ded particulates as well as a wider deviation of individual readings. This latter point is illustrated in Fig. 2 which gives the frequency distribution of

TABLE 5 Grime on Aluminium (A)

Note: Mean L value of originals 68.7

masses collected on the filters after 24 hours of sampling at 50 L/min.

Table 12 shows data on the dis­colouration of the filter by the suspen­ded particulates collected, in terms of the relation between mass collected and change of whiteness (AL). While the correlation coefficients are not high the relations between AL and mass collec­ted are very similar for each site. While indicating little variation in darkness of the particulates at the different sites the

results also indicate that measuring darkness discolouration is an approx­imate measure of the mass of grime collected.

4. DISCUSSION

4.1 Influence of Different Sites

It is apparent from the data in Tables 2 to 8 that grime deposition is accumula-

Clean Air/August 1986 Vol. 20/3

97

tive. For 80 percent of cases LF is greater at 24 months than at 12 months. This indicates that rain does not com­pletely clean specimens. It would, how­ever, remove loose dust aad because of this it is considered that the fixed grime

LF is a better indicator of perfor­mance of specimens and severity of sites than total grime or removable grime LR.

As expected the fixed grime is gen­erally but not always much greater on horizontal than on vertical surfaces.

The only consistent observation on the results at the different sites is that all specimens except unpainted aluminium at 24 months suffered greatest grime accumulation at site 6. The accumula­tion of fixed grime ( LF) is little dif­ferent for sites 1 to 5 despite the much greater dustfall at site 1. The data are much more consistent for the painted surfaces and the glass. For the latter specimens sites 6 then 1 are most severe with little difference between the other sites. This ranking of sites is similar to the ranking for dustfall in Table 9 except that site 1 has greater total dustfall than site 6. Site 6, however, has more dust that is water soluble. A high degree of correlation (R = 0.93) is found bet­ween the total water soluble dust and

LF for the painted specimens and glass exposed horizontally for all sites using both the 12 months and the 24 months data The relations are

(a) Y=6.34 X ~ 2.6 at 23 months, and (b) Y= 0.58 X " 4.5 at 24 months, where Y is LF and X is the 12 month's total freefall dust solubles (g/m2).

Table 11 indicates that site 6 also has more suspended particulates than site 1 but there is little difference bet­ween sites 1 and 3. It is reasonable to assume that the suspended particulates provide a significant proportion of the water soluble or ultrafine dust Unfor­tunately, there are too few data to explore this matter.

The only consistent data for the ver­tical specimens are that those at site 6 accumulate more grime than those at the other sites.

4.2 influence of Different Specimens

A comparison of the relative behaviour of the different specimens is given in Fig. 3 in terms of LF summed for all the sites ( except site 5 where specimens were damaged). The ranking of dif­ferent specimens is similar for both horizontal and vertical and 12 and 24 month exposures. Aluminium retains the most grime followed by the concrete

TABLE 8 Grime on Glass (G)

Site L R LF

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

Horizontal Vertical

12 months

1.7 0.6

0.5 0.3

0.9 0.2

0.7 0.2

0.8 0.1

3.7 5.7

24 months

3.6 0.6

D D

0.2 0.4

D D

D D

6.9 D

12 months

3.3 0.5

0.1 0.1

0.5 0.1

1.1 0.1

1.4 0.4

7.0 2.9

24 months

6.6 1.3

D D

1.0 0.1

D D

D D

12.6 D

Note: Mean L value of originals 86.5

TABLE 9 Total Dustfall and Percentage Solubles for the First 12 Months

Month Site

July

Aug

Sep.

Oct

Nov.

Dec.

1981

J aa 1982

Feb.

Mar.

Apr.

May

June

Total dust

Total solubles

% solubles

Note: Dustfall units % solubles in

1

23.4 (6.2)

30.7 (5.2)

38.5 (3.7)

49.2 (2.3)

65.5 (3.6)

23.4 (3.2)

15.5 (4.0)

18.5 (5.3)

12.9 (9.6)

8.9 (13.1)

11.6 (11.0)

10.3 (11.3)

308.3

15.5

5.0

are g/m2. parentheses.

2

1.9 (39)

3.0 (42)

2.7 (29)

4.4 (I.1)

3.9 (56)

8.3 (4.0)

3.3 (7.0)

3.2 (24)

3.8 (7.9)

3.6 (42)

3.4 (46)

1.4 (46)

42.9

10.8

25

3

2.5 (30)

3.6 (25)

2.9 (16)

3.6 (12)

7.9 (24)

6.4 ' (5.4)

7.4 (14)

2.2 (17)

4.4 (7.5)

3.0 (32)

2.7 (35)

2.3 (38)

49.0

9.4

19

4

3.2 (65)

3.3 (47)

3.0 (29)

2.9 (21)

3.8 (51)

5.4 (5.8)

5.2 (15)

3.2 (19)

3.8 (22)

3.4 (39)

1.8 (17)

2.3 (56)

41.3

12.5

29

5

2.2 (69)

2.9 (59)

2.4 (28)

6.7 (18)

4.8 (47)

7.2 (7.1)

5.5 (9.8)

2.5 (22)

2.5 (5.6)

4.0 (41)

2.0 (33)

2.2 (72)

45.0

13.0

29

6

15.1 (17)

23.0 (5.8)

22.1 (7.1)

25.2 (7.1)

28.4 (16)

21.4 (8.4)

22.0 (20)

20.2 (9.8)

19.0 (14)

14.8 (7.2)

10.9 (9.7)

12.7 (I1)

234.8

26.3

11

surfaces, then generally the painted surfaces, which differ little from glass. Since the aluminium metal was origin­ally darker than the other specimens, and hence of less contrast to the dark grime, it may be argued that the mass of grime retained on the aluminium must have been even greater compared to the other specimens than indicated by the

L F results. The difference between the rough

and smooth concrete is attributed to a greater mass of grime being retained on the roughened surface. The relative

retention of grime for the horizontal compared to the vertical exposures is much higher for the concrete surfaces than for the other specimens. Painting concrete markedly reduces grime reten­tion on horizontal surfaces (ca. 70 per­cent reduction) but surprisingly has no such effect on vertical surfaces. Paint­ing aluminium markedly reduces grime collection on both horizontal and verti­cal surfaces (ca 70 percent reduction).

A general explanation for the obser­vations on the different specimens can be postulated in terms of the glass and

98 Clean Air/August 1986 Vol. 20/3

painted surfaces being relatively inert to grime and the concrete and aluminium being relatively active. The activity involves reaction between the water soluble components of the dustfall and the surface, and the reactions of attach­ment occur when the surfaces are wet after draining of free water from the sur­face. The horizontal surfaces remain wet for longer periods after rain or dew deposition than the vertical surfaces and hence more reaction of attachment takes place. Aluminium is more reac­tive than concrete and the vertical sur­face would be subjected to dew deposition more frequently than the vertical con­crete specimen. Obviously, time of wetness measurements are needed to provide more information. Such studies are proceeding with the development of an instrument to measure duration of wetness on different surfaces.

Since it is well established that grime promotes corrosion of aluminium, there is a particular need to reduce grime

Figure 2 Distribution of mass of suspended particulates for three sites.

retention on this material. Whether or not grime promotes deterioration of concrete has not been established. Some information on this aspect is being sought by re-exposing the specimens at most sites to see whether the grime influen­ces the rate of change of the pH of the concrete. The pH changes from about 10.5 to 8 in clean atmospheres by car-bonation of the free lime beginning at the exposed surface. It is a very slow process, usually measured by treat­ment of a fractured cross-section with phenolphthalein to indicate the dis­tance from the surface of the pH change. The concrete specimens that had been exposed for two years were split and measured but little pH loss had occurred and no differences between the rough, smooth, and painted concretes at the different sites could be discerned It is expected that five years exposure will be needed to show up any differences.

It is apparent that horizontal exposure at site 6 is the most severe for grime accumulation. The site is not abnormal in that the colour of the suspended par­ticulates is similar to that for the other sites (Table 12) and the percentage water solubles of the dustfall are lower

TABLE 10 Rainfall Collected for the First 12 Months

Month Site

July 1981

Aug.

Sep.

Oct

Nov.

Dec.

Jan. 1982

Feb.

March

April

May

June

Total

1

1 823

2 242

670

1 256

1 505

600

1 172

177

1 305

1034

1 557

850

14 191

2

3 179

3 275

1 124

1 674

2 548

1 102

1 742

219

I 634

2 447

2814

1 645

23 403

3

1 715

2 107

451

2 024

1 851

738

2 133

142

1 346

1 165

1 414

900

15 986

4

2614

3 043

821

1057

2 364

1 167

1419

118

1539

2 802

1780

1590

20 314

5

2 738

3 114

826

1 157

2 684

1445

1 544

203

1657

2 806

1 874

1609

21662

6

1656

1702

490

930

1 118

449

1 177

150

1 076

794

1 927

520

11089

Note: Units are g collected

TABLE 11 Measured Suspended Particulates

Site

1

3

6

Average (mg/L)

1.18xl0~3

1.12xl0-3

1.94xl0-3

Number* of

readings

24

34

30

Standard deviation

0.25xl0-3

0.55x10-3

l.OlxlO-3

* Each reading sampled 50 L/min for 24 h.

TABLE 12 Relations between Mass of Suspended Particulates and Discolouration of White Filter ( L)

Site

1

3

6

Linear correlation

coefficient, R

0.466

0.718

0.767

Relation

L= 0.19 M + 2 3 . 2

L = 0 . 2 1 M + 21.3

L = 0 . 1 5 M + 26.3

All sites 0.755 L = 0.17 M + 24.-8

M= mass collected (mg) over 24 h. sampling at 50 L/min.

than the average of all the other sites (Table 9). It is thus suggested that this site be used for assessing the relative performance of different surface treat­ments aimed at reducing grime accumu-latioa An exposure period of 12 months should give meaningful data

5. CONCLUSIONS

1. Large differences in the amount of freefall dust are found between dif­ferent sites about urban Melbourne. Smaller differences are found for total water solubles of the dust and for sus­pended particulates. The darkening effect of the suspended particulates is

similar at the different sites. 2. Fixed grime accumulation, in terms of darkening effect retained after a stan­dard cleaning procedure ( Lp), was found to relate to water solubles of the dustfall for each site for inert surfaces such as paint and glass. Linear equations

Figure 3 Grime on different specimens summed for five sites (2 LF) for both 12 and 24 months exposure.

Clean Air/August 1986 Vol. 20 /3

9 9

were established for 12 and 24 month exposures for horizontal surfaces. For concrete and aluminium, the darkening effect of the grime was not linearly related to dustfail, water solubles, or suspended particulates.

3. Aluminium accumulates more grime than concrete which in turn accumulates more than painted surfaces which differ little from window glass. Painting alum­inium was found to reduce grime accumu­lation by 70 percent for horizontal and vertical surfaces. Painting concrete also reduced grime accumulation on horizontal surfaces by about 70 percent but had no such effect on vertical sur­faces. Smooth concrete accumulated about 25 percent less grime than rough concrete on both horizontal and verti­cal surfaces.

4. Additional studies on wetness of surfaces are needed to gain further under­standing of the grime accumulation mechanism and longer term studies to determine whether grime accumulation causes deterioration of concrete.

5. It is suggested that horizontal ex­

posure at the most severe site could be used to assess surface treatments aimed at reducing grime accumulation.

S. ACKNOWLEDGEMENTS

The authors wish to thank the Environ­ment Protection Authority of Victoria for provision of exposure sites and helpful discussions on this project, the Road Construction Authority Victoria for provision of the Mulgrave exposure site, and Mr. I. Sasnaitis for assisting with the experimental work.

REFERENCES

1. Martin, K.G. Reactions between vehicle emissions and building materials. Clean Air AusL, 17. 60-65(1982) November.

2. Salmon, R.L. (1970). Systems analysis of the effects of air pollution on materials. Final Report Mid- West Research Institute, Project No.33231).

3. Liu, B. andYu, E.S. (1976). Physical and economic damage functions for air pollut­ants by receptor. Environment Protection Agency Report600/5.7.0l 1, Triangle Park, North Carolina.

4. International Council for Building Re-

10.

12.

search Studies and Documentation (1977). Symposium on Evaluation of the Performance of External Vertical Surfaces of Buildings, Espoo, Finland Ballantyne, E.R. and Tilley, R.I. (1970). Durability of polyethylene and polyvinyl-chioride film materials. CSIRO Division of Building Research Report 04.2-7. Martin, K.G. (1973). Atmospheric corro­sion of metal cladding in Papua New Guinea and Melbourne. Australasian Corrosion Engineering, May, pp. 19-28. Raaschou- Nielsen, H.K., Kornum, L.0 and Saberg, O. (1978). Dirt retention on painted surfaces. Journal of Coatings Technology, 50, pp.69-80. Standards Association of Australia (1964). Latex paints for interior and ex­terior use. AS K 122. Standards Association of Australia (1975). Wrought aluminium and aluminium alloy flat sheet, coiled sheet and plate for general engineering purposes. AS 1734. Beloln, N.J. and Haynie, F.H. (1975). Soiling of building materials. Journal of the Air Pollution Control Association, 25(4), pp. 394-403. Glasser, L.G. and Troy, D.J. (1952). Colour coordinate tables. Journal of the Optical Society of America, 42, p.652. King, G.A., Martin, K.G. and Moresby, J.F. (1982). A detailed corrosivity survey of Melbourne. CSIRO Division of Build­ing Research Report, Melbourne

100 Clean Air/August 1986 Vol. 20 /3

VICTORIA and TASMANIA BRANCH SYMPOSIUM

HIGH TEMPERATURE INCINERATION OF HAZARDOUS WASTES

High temperature incineration is widely seen as the most cost-effective and effi­cient way of disposing of intractable environmentally hazardous wastes, most particularly stable organo-chiorines.

In Australia at present wastes requir­ing high temperature incineration, that is, a final gas retention time of at least 2 seconds at 1200° C, are either stored or shipped to the United Kingdom or to France for incineration. There is some doubt that shipping will be allowed to continue. There is further doubt that Australia will be able to attract a future visit from an incinerator ship such as the "Vulcanus" which was suc­cessfully used to deplete stockpiled material in 1982.

There is, therefore a need to assess the situation in Australia and to examine the options available. The seminar reported here was intended to make available current thinking on high tem­perature incineration and open up in­formed debate.

Much discussion has centred round a national facility. So far any proposals for such a facility have foundered in the public arena; the paper by Terry McKay presents a Northern Territory proposal for such a facility near Tennent Creek. This proposal has the express intention of importing hazardous wastes from the South East Asian region. This not only provides a stronger economic base but also gives a technical advantage in ensuring a supply of feedstock suffi­cient for the efficient running of the fur­nace. The low volume feedstock streams within Australia make the provision of the kind of homogeneity of feed neces­sary for the proper running of a high temperature incinerator difficult Low volume feedstocks are a particular pro­blem if some of the waste is solid. These and associated problems are discussed in the paper by Tom Gumming from ICI.

The problems are brought further into perspective when ICI's contribu­tion to the annual production figures of organo-chlorine is examined. Any fac­ility built for national use would be very dependent on ICI supplies at a time when the company has greatly improved

its ability to recover the recycle liquid organo-chiorines and are searching for alternatives to combustion for their solid organo-chlorine wastes.

Legislation has recently been passed in Victoria enabling the Melbourne Metropolitan Board of Works (MMBW) to construct whatever facilities are necessary to handle hazardous waste materials in the State. The Board's point of view is put in the paper by David Crammond. In brief, this involves one of four incinerator options, all in­volving high temperature incineration, either of a wide range of organic feed­stocks, only a fraction of which require high temperature treatment, or separat­ing out the organo-chiorines to be in­cinerated. It appears that the MMBW is not envisaging any solid organo-chlorine material requiring treatment in Victoria

An overall view of some of the safety, siting and technical requirements for high temperature incinerators is given by Alan Crapp. One of the alternatives he mentions, though not with favour, is a mobile incinerator. This solves the problem of transporting hazardous wastes which will surely be one of the major focusses of opposition to a national facility. One such furnace has been designed at CSIRO and its operation is described in Peter Wailes' paper. Such a small incinerator could conceivably handle all of one State's organo-chlorine liquids, leaving the more easily trans­ported solids for a national incinerator if technically feasible at low feed rates, overseas shipping or other technologies.

In summary, there are sources of intractable organic wastes in Australia that need to be dealt with. High tem­perature incineration is the most rea­sonable way to do this. However, the Australian waste stream is likely to be too small to make this an attractive pro­position economically or technically unless the waste stream is substantially diluted by other organic wastes, either similarly intractable ones from over­seas or local organic waste streams that do not require such high temperatures for their disposal. Small mobile incin­erators combined with careful analysis of the feedstock may also provide a use­ful alternative.

The major obstacle to any incinerator proposal will in the end be the obtaining of public acceptance to such a facility being in "their backyard". The follow­ing papers are abstracts of the papers presented to a joint symposium of the Clean Air Society and the Environ­mental Branch of the Institution of Engineers Australia at the MMBW premises in Melbourne on 1 May 1986.

THE NORTHERN TERRITORY VIEW

Terry McKay Department of Mines and Energy, Darwin

BACKGROUND

An anouncement was made late in 1985 to the Australian Environmental Coun­cil, the Commonwealth Minister for Arts, Heritage and Environment and to other State Governments by the Chief Minister of the Northern Territory, Rt Hon Ian Tuxworth, that the Northern Territory will construct a high tempera­ture incinerator facility in a remote location in the Territory for the express purpose of destroying classes of hazar­dous waste materials which cannot be disposed of by more conventional means.

The need for Australia to have access to such a facility to destroy the rela­tively small but environmentally sig­nificant quantities of intractable chemical wastes from a range of indus­tries has been discussed for several years in the Australian Environment Council and its committees. At least three State Governments have at some time in the last few years actively con­sidered the installation of such a facility, only to find at an early stage of each proposal that socio-environmental as­pects have loomed more prominently than the techno-environmental aspects of the projects.

PROJECT DEVELOPMENT

The importance of public involvement in early developmental planning stages appears to have largely been overlooked in the past Apart from the need for some degree of confidentiality in con­ducting preliminary engineering and economic investigations related to the assessment of overall project viability, it is recognised that communities likely to be involved in such proposals need to be given adequate opportunity to con­sider the range of implications, includ­ing the balance of their advantages and disadvantages.

The Northern Territory approach to this incinerator project was developed with the intention of importing indus­trial wastes from the South East Asian regioa It was particularly encouraging that the Minister for Arts, Heritage and Environment, at the International Con­ference on National Strategies for Managing Hazardous Wastes (Mel­bourne, November 1985) stated that Australia should be prepared to assist

Clean Air/August 1986 Vol. 20/3

101

Asian and South Pacific neighbours by sharing of expertise and by providing joint disposal facilities. Common­wealth support will also be needed to establish import protocols in line with recent OECD decisions for transfron­tier movement of hazardous wastes.

Earlier Australian proposals have considered the magnitude of the Aus­tralian hazardous intractable wastes problem as almost too small to com­mercially support anything larger than a unit with capability to destroy around 2000 tonnes per year. The Northern Territory installation would be in close proximity to relatively large tonnages of wastes known to be present in South East Asia. First estimates indicate that a base load of at least 20,000 tonnes per year would be available from near neighbouring countries. Relatively low cost sea freight rates (offset to some extent by recently established inter­national requirements for high insurance premiums) give the Port of Darwin a substantial advantage over more dis­tant Australian and particularly over any European ports as the most eco­nomically favourable to handle such wastes in transit for high temperature destructioa

OPERATIONAL ADVANTAGES

A proposed incinerator site in the Barklay Tablelands region near Tennant Creek has a number of advantages, such as its: • remoteness, • environmental security, • arid climate and stable geology, • accessibility to the trunk-line high­

way network serving eastern and southern States through Queensland,

• acceptable distance from the Port of Darwin,

• adjoining the Amadeus Basin to Darwin gas pipeline, providing low cost fuel source,

• proximity to a regional population centre which would benefit from new technology and diversification of the existing mining industry. The Northern Territory Govern­

ment has gained considerable experience in the monitoring of mining, rehabilita­tion and other developments in sensi­tive natural environments. This experience, involving the co-ordination of several regulatory authorities, provides a valu­able background for adequate regulatory activities. The Dangerous Goods Act provides for strict controls on hazar­dous waste disposal operations and would be used to frame appropriate regulations for safe transport, storage

and handling procedures. In addition to the benefit to the local

population arising from the employ­ment prospects of the incinerator facility, suitable supporting industries can be co-located. These include industries based on electrolytic metallurgical and electronic grade metal manufacturing projects which would utilise relatively low cost electricity generated from waste heat. Refrigerated warehouse facilities could be developed to service the road and future rail freight industry.

A regional technical centre would be developed which would utilize exten­sive laboratory facilities needed for quality control and monitoring. This would incorporate highly sophisticated chemical analytical instrumentation which could also provide facilities needed for advanced metallurgical research and service local and regional mineral exploration activities. This has prospects of attracting business from the north-eastern and north-western areas of Australia.

C O N C L U S I O N

It is recognised that there are important underlying criteria in the development of the project which are essential com­ponents in encouraging responsible attitudes towards reduction or elimina­tion of wastes by manufacturing indus­tries. In recognition of the Polluter Pays principle, the development of a cost structure policy for incinerating various classes of wastes will need to reflect a balance between actual oper­ating costs and the appropriate economic inducements to encourage in-plant waste reduction by manufacturers. It is not intended that the incinerator merely provides an easy low-cost option for them to ignore waste production pro­blems.

Many critical decisions are yet to be made to establish the ultimate viability of this venture. Important con­sultations with representative groups of people who are likely to be involved in key parts of the project will be organised in the near future. All indications to date support the initial enthusiasm that the Northern Territory incinerator will provide a key facility in an overall strategy for dealing with present inven­tories of hazardous wastes in a manner which is environmentally sound and for promoting the cause for hazardous waste reduction, both in Australia and in our neighbouring regions of the world.

DO WE NEED A HIGH TEMPERATURE INCINERATOR IN AUSTRALIA: AN INDUSTRY VIEW

T.M. Gumming, SCI Australia Operations Pty. Ltd.

INTRODUCTION

ICI Australia Operations(ICIA) manu­factures chlorinated solvents and ethy­lene dichloride at Botany in NSW and generates organochlorine wastes from these two processes. Company concern and involvement with recycling and disposal of organochlorine wastes ex­tends from the early 1970's to the pre­sent time.

High temperature incineration has been studied extensively as a practical and economic means for disposal of solid waste and was taken to the stage of design of a dedicated high temperature incinerator. Ocean incineration has also been studied and, in fact, the only significant incineration of organochlorine wastes that has occurred in Australia was arranged by ICI A in 1982 when the incineration ship "Vulcanus" was chartered to burn liquid wastes.

ORGANOCHLORINE WASTE IN AUSTRALIA

The Australian Environment Council (AEC) published during 1985 a 'Dis­cussion Paper on Disposal of Stable Organochlorine and Related Chemical Wastes'. It followed a 1982 Report 'Hazardous Chemical Wastes' pro­duced by a House of Representatives Committee, and a 1983 Report by the AEC, 'Management and Disposal of Hazardous Industrial Wastes'. It stated, in effect, that organochlorine wastes and certain pesticides require specialised disposal processes. It developed a case for a single national incinerator as a necessary disposal facility.

This case was supported by a Table which listed, on a State basis, stocks and generation rates of organochlorine wastes in 1985. It is possible to extra­polate the Table to 1988 by means ofits explanatory notes and by taking ad­ditional recycling at ICI A into account. The resulting data suggests a national stock of 9240T( 84% ICI A) and annual generation rate of 580T(76% ICIA). The AEC notes imply that there is some uncertainty about the amounts of non-ICIA waste.

102 Clean Air/August 1986 Vol. 20/3

It is quite apparent that the size of any national incinerator would depend upon whether or not it is to be used for the ICIA waste.

HUGH TEMPERATURE INCINERATION

Incineration is not a new technology and has been used for treating liquid and solid organic wastes for many years in Europe and the USA. Land-based incinc; titers may be installed by the waste generator, preferably at the source of the waste, or they may be commer­cially operated. Ocean incineration, however, was introduced about 1970 and operates on a commercial basis. It is at present designed exclusively for incineration of liquids and is not ap­propriate to the ICIA wastes which are mainly solids.

Incineration is a continuous chemi­cal process in which ail variables must be kept relatively constant if high pro­cessing efficiency is to be achieved. Waste feed rate is one such variable together with others such as pressure, temperature, concentration and gas How rate. Any incinerator for organo-chlorine wastes in Australia would be unlikely to have a capacity of more than 2000 tonnes/year and may well be much, smaller. The equivalent amount of waste burnt in the defined minimum residence time of two seconds would be about 170g. Even a residence time of five seconds is equivalent to only 400g of waste. Any suggestion of slug-feeding such an incinerator with, say. whole drums of waste is completely unreal­istic.

Liquid wastes could be pumped to a burner in an incinerator at any selected rate and allow reliable, constant incin­erator operating conditions. Solid wastes are another matter, particularly if they are coarse or irregularly sized, damp, or containing foreign material. Other dif­ficulties arise if the solid has a low melt­ing point or boiling point. Design of appropriate waste feeding equipment that will reliably deliver a designated, constant small flow of solid to an in­cinerator may be difficult. The incin­erator designer needs to be fully aware of the properties of the waste feed, par­ticularly if it is a solid.

EXPERIENCE WITH RECYCLING AND INCINERATION

ICI has two plants which produce organo-chlorine wastes. The Ethylene Dichloride(EDC) Plant produces light

and heavy liquid fractions which are mainly low carbon number chlorinated aliphatics. The Solvents Plant once produced heavy ends, which was a mix­ture of liquid and solid compounds, but now produces only solid hexachloro-benzenc.

The Solvents Plant was intended to utilise the liquids from the EDC Plant in the manufacture of carbon tet­rachloride and perchlorethylene but some liquid accumulated initially. Until about the mid-1970's research and development effort was mainly direc­ted towards recycling liquids, both accumulated and new material, to the point in 1977 that 2400t/year of liquid organochlorine compounds from the EDC Plant were being recycled to pro­duce solvents. A stock of about 1 500t of liquid waste existed and one heavy tarry liquid waste was being generated at the rate of about 600t/year.

The heavy ends material from Sol­vents Plant was accumulating until 1977. Research and development had indicated a process for recovery of the liquid phase to leave only relatively pure and dry solid hexachlorobenzene.

Prior to 1977 ICIA was pro­gressively resolving its organochlorine waste problems. Various external ini­tiatives then commenced and interac­ted with ICIA proposals. Disposal actions since 1977 are summarised below to indicate the success achieved with liquids compared to solids.

Post 1977 Disposal of L iquids

• The Solvents heavy ends treatment plant was designed and built in 1977. It recycles the liquid phase to leave solid hexachlorobenzene.

•The ocean incineration ship 'Vulcanus' was chartered by ICIA in 1982 and used also by a Victorian company to burn ethylene dichloride plant liquid wastes. Other organisations then used it for incineration of polychlorinated biphenyls.

• A thin film evaporator was installed in i 983 to recover and allow recycl­ing of about 350t/yr of liquid waste.

• A flash evaporator will be installed in 1987 for treatment of the under­flow from the thin film evaporator to recover the final 200t/yr of liquid waste for recycling.

Post 1977 Attempts to Dispose of Sol ids • The 1979 proposal for the Met­

ropolitan Waste Disposal Authority to build a multi-purpose waste treat­ment plant included a high tempera­ture incinerator suitable for disposal

of hexachlorobenzene as well as other organochlorine waste. This pro­posal was withdrawn in 1982 as a consequence of public opposition.

© A flame-combustion process applic­able to hexachlorobenzene was developed and patented in 1983. It was not proceeded with because the technology was not as advanced as incineration.

® A dedicated incinerator for ICIA wastes was designed but incinera­tion at Botany ceased to be an option in 1985 following discussions with the Government.

© Rejection of the incinerator pro­posed for the Broken Hill area oc­curred in 1985. ICIA would not be a party to this proposal because of its perceived faults. There was con­siderable public opposition to the proposal.

CONCLUSIONS ABOUT ORGANOCHLORINE WASTE DISPOSAL

Probabi l i ty of Estab l ishment of HTI

It is impossible to be optimistic about the probability of an incinerator being established in NSW in the near future, say within the next five to ten years, despite the obvious need for it

The problem is sociological rather than technological. An indisputable fact is that community perception of incineration is unfavourable and local commuity opposition to any specific proposal tends to be extreme. The fac­tors which lead to community opposi­tion include: • Lack of public confidence in science

and technology. • Unfairness in the siting process. • Lack of adequate consultation. • Misinformation and misunderstand­

ing. Although various ways of overcom­

ing siting problems have been sugges­ted, the process would be long and expensive and without any certainty of success.

However, despite the unfortunate history of incineration in Australia and the poor prospects for it, ICIA remains convinced that it is appropriate tech­nology and would support its intro­duction.

Re-assessment of Disposal Requirements

As indicated earlier disposal of ICIA liquid wastes by once-only ocean in-

Clean Air/August 1986 Vol. 20/3

cineration and recycling will have elim­inated liquid waste generation by 1987 and stocks soon afterwards. Actions to achieve this were initiated, arranged, and managed by ICIA.

The disposal of solid waste has been unsuccessful because of the objective of achieving it by incineration on land. It was seen to be a catch-all process applicable to liquids as well as solids. It could cope with drums and other mis­cellaneous materials.

The progressive resolution of the liquid waste problem means that the remaining problem is mainly solid hex-achlorobenzene. The question is then whether a suitable alternative to incin­eration can be found which can convert, and recycle, this specific material. The miscellaneous materials mentioned earlier could be separately treated, for example by washing drums prior to re­cycling as feed to a blast furnace.

Recycling of Hexachlorobenzene

A substantial research programme is in progress to identify and evaluate the most suitable alternatives to incinera­tion for application to hexachloroben-zene. Two obvious examples of such alternatives are: • Gas-phase Hydrogenolysis

Several applications of this process have recently been reported by a group of Dutch workers. The pro­cess operates at atmospheric pre­ssure and about 900°C. It converts hexachlorobenzene to benzene and hydrogen chloride.

• Chlorinolysis Almost all organochlorine com­pounds can be converted to carbon tetrachloride by reaction with chlorine under appropriate conditions. The Hoechst process, for example, oper­ates at 200 ats and 600° C. Various appropriately catalysed processes employ less rigorous reaction con­ditions.

Economics

During the 1970's and early 1980's HTI was regarded as the most approp­riate disposal option for both technical and economic reasons. The economic justification is not so obvious now by comparison with recycling processes.

Two influences which have an inflat­ionary effect upon costs are apparent One is the possibility of incineration at a remote location requiring additional costs for transport, labour, services, and infrastructure. The second influence

is comparison with the total cost of incineration of Australian waste in Europe and the inference that incinera­tion in Australia need only be slightly cheaper to be acceptable.

CONCLUSION

The answer to the question 'Do we need an incinerator in Australia? is obvious; we do need such a facility. The question of the size or capacity of it is much more difficult to answer.

The ICIA position has already been indicated. The use of incineration for disposal of organochlorine wastes is regarded as technically and environ­mentally satisfactory. In the event that a properly designed and operated in­cinerator could be established either by a Government or commercial organisa­tion, and if the cost of incineration is acceptable, then ICIA would willingly consider being a party to it.

However, the uncertainty about an appropriate incineration facility ever actually eventuating means the ICIA, as a matter of common prudence, must seek an alternative process to solve its organochlorine solid waste problem. Once this has been achieved then the most significant potential feed stock for an incinerator will be removed. There appears to be a lesser organochlorine waste problem which is independent of ICIA. The amount of this material and the probability of its disposal overseas would determine the need for an incin­erator for it alone.

HIGH-TEMPERATURE TOXIC WASTE INCINERATION A REGULATORY VIEWPOINT

Alan Crapp. B.E. NSW State Pollution Control Commission

Incineration of toxic wastes to basically harmless products of combustion is widely accepted as the preferred alter­native to land fill, long-term storage or illegal dumping

There is no doubt that technology exists to build effective high-temperature incinerators capable of oxidizing vir­tually all intractable or highly toxic organic wastes and to clean up the exhaust emissions to very low levels. My concern and the concern of regu­latory authorities around the world is

the need for operating and management practices of a standard to match the high technology of the hardware.

To operate effectively, the manage­ment of the destruction process must start right from the point of generation of the toxic wastes. The early and accurate identification and recording of the waste together with its correct pac­kaging storage and labelling is the foundation on which to build any suc­cessful waste management system. Obviously, the generator of the wastes is better placed to carry out these functions than any subsequent agent in the handling and disposal chain.

The safe and efficient transport of the wastes to the point of destruction or disposal is the next link in the chaia The shorter the distance and fewer the transfer operations involved in con­veyance, the safer will be the execution of this step. This introduces the first of many alternatives of disposal philosophy in toxic waste management There is a strong case for destruction of the waste at the point of generation by or on behalf of the generator of the waste product

There are, however, disadvantages in this approach. Firstly it would lead to proliferation of disposal sites, with con­sequent increase in overall capital and operating costs and difficulty of regu­latory supervision Secondly, the loca­tion of the sites where the wastes are generated may be unacceptable for in­stallation of disposal plant In the case of PCB' s from electrical transformers there is not the infrastructure available "in house", as there would be at a chemical works, to manage the destruc­tion process. A mobile incinerator plant would help to overcome some of these problems but by no means all and would introduce new complications.

The concept of a centralized all-purpose incinerator for destruction of toxic wastes appears to be the favoured alternative at present However, there are also drawbacks to this option As yet a suitable site has not been iden­tified There has been and will continue to be intense public opposition from residents in any locality or region pro­posed for the construction of Aus­tralia's one and only toxic waste in­cinerator. Apparently, 20 kilometres separation from a residential area is not considered adequate. Yet with increas­ing isolation of the plant comes longer distances for transport of wastes, and longer travelling times for operating staff and regulatory inspectors. A buf­fer zone of 4 to 5 kilometres would nor­mally be adequate for reasons of health and safety.

104 Clean Air/August 1986 Vol. 20/3

For any multi-purpose plant required to handle toxic wastes, a high level of management and control of inventory and storage is essential so that the specification is known of any material or mixture of substances being burned. It is too iate to find out what is being burned after it is in the furnace.

Turning to the incinerator and gas cleaning piant, I am sure that, given a detailed specification of the wastes to be burned, a suitable installation can be designed and built By far the greatest problem with the operation, is the short-term malfunction or control ex­cursion. Obviously, the plant must operate on a fail-safe principle and this will require some duplication of ancil­lary components such as induced draft fans, combustion air fans, auxiliary burners, temperature indicators, etc. A large heat retention capacity in the fur­nace is also highly desirable where solids are being bumed especially if in 200 litre drums.

Monitoring of plant performance and interlocking the entry of toxic wastes into the furnace to adequate plant per­formance parameters is the key to a high standard of plant operation. To emphasize the necessity of correct plant operation at all times, I quote two examples: 1. A plant handling PCB's and oper­

ating at 99 percent efficiency would emit more toxic substances into the air in one hour than in a year when operating at its design efficiency of 99.9999 percent

2. A plant handling organochlorine pesticide wastes at 95 percent ef­ficiency would emit as much toxic substances into the air in a shift as in six months operating at 99.99 percent destruction and removal efficiency (DRE).

Added to the much higher rate of emission, is the dispersion effects from the stack, which produce higher max­ima and average concentrations for a shorter time base.

Monitoring of plant performance would include continuous measure­ment and recording of: • Primary and secondary combustion

chamber temperature. • Oxygen content of flue gas after

secondary chamber. • Combustibles or carbon monoxide

in flue gas. • Primary furnace draft • Rates of charging of toxic wastes.

This would be supplemented by ran­dom sampling of flue gases for highly toxic or intractable substances, heavy metals, hydrogen chloride, chloroform benzene, etc. on a programmed basis.

In keeping with current practice, the regulatory authority would expect monitoring data to be summarized and reported on a regular basis by the operator. The authority would supple­ment this with routine inspections and random audit testing of emissions and checking of instrument calibrations.

Finally, the disposal of solid and liquid residues from the plant needs to be properly managed. Accurate analysis of residues is necessary before a suit­able method and location for disposal can be determined.

In summary, I believe that a well designed and constructed plant for the destruction of highly toxic and intract­able wastes can be operated effectively to avoid any long or short-term threat to the environment However, we must get away from the mental attitude that gardeners and cleaners operate incin­erators. The management and opera­tion of such a facility should be placed in the hands of competent professional and technical staff, adequately policed but not suffocated by an effective re­gulatory authority.

THE MMBW APPROACH TO HIGH TEMPERATURE INCINERATION

David Crammond Melbourne Metropolitan Board of Works

VICTORIAN STRATEGIES

Following the 1982 state elections, the Victorian EPA began preparing a com­prehensive strategy for management of industrial waste.

The direction of the work was de­fined by a special task force in May 1982. Community and industry liaison was formally established through a new advisory committee. Specialist work­ing groups including government experts developed some of the underlying con­cepts such as legislation, site selection procedures, and recommended dis­posal methods. Newspaper adver­tisements in October 1984 invited public submissions on waste management issues.

A draft strategy was published by the EPA in July 1985. After a period of public comment a final strategy was prepared. This document has now been adopted by the State Government The following are some key outcomes of the strategy. 1. Waste Management Preferences

for Victoria

First preference - Waste minimi­sation Second preference- Waste recycl­ing Third preference - Effective treat­ment and disposal

2. Recognition of the need to cease landfilling of liquid wastes.

3. Recognition of the need to establish effective incineration facilities to provide a comprehensive system for Victoria's Industrial Wastes.

4. Recognition that there should be two arms of Government involved in management of Victoria's In­dustrial Waste. • The EPA as the "Regulator" • The MMBW as the "Operator"

The roles of the Victorian EPA and the MMBW were given a statutory framework with the passage of the En­vironment Protection (Industrial Was­tes) Act in late 1985.

In accepting its new Industrial Waste responsibilities, the MMBW has re­viewed the systems of waste manage­ment which operate elsewhere in the world.

It has been concluded that the European-type of Integrated Waste Treatment Facility will be most appro­priate for Victoria's needs. This type of facility combines a number of treat­ment technologies within one site.

Considering the wastes generated in Victoria, it is expected that the MMBWs Integrated Waste Treat­ment Facility will combine the follow­ing key treatment elements • Physical/Chemical Plant for aqueous

wastes • Chemical Fixation Plant • Oil and Solvent Recovery • High Temperature Rotary Kiln

Incinerator In addition the infrastructure will

include a laboratory, holding tanks, drum unloading facilities, safety services and gas deodorising plant

The MMBW has now commenced a major process of public consultation to determine an appropriate site for this facility. It is intended to commence operation of a multipurpose incinerator in 1990. The incinerator will be a very important element of the MMBW In­tegrated Facility. It is intended that the incineration be used to destroy a wide spectrum of combustible wastes, and not just the so-called Intractables. By adopting this approach it will be poss­ible to minimise the landfilling of organic materials in Victoria

Since the supporting infrastructure for an incinerator costs more than the rotating kiln itself, the unit cost is sign­ificantly dependent on the projected

Clean Air/August 1986 Vol. 20/3

105

throughput If it is proposed to burn only highly intractable material such as polychlorinated bi-phenyls and hexa chloro benzenes the only facility that would be viable would be one operating on a national basis. This would have a capacity of approx. 5M BTU/hr. i.e.. l-2000t/year of chlorinated waste at a cost of approx. $2m. However, if a facility is required to destroy a wide spectrum of industrial waste a plan! capable of handling 20,000 t/year would be required for Victoria at a cos; of approx. $10m. This would be more economical to run due to the higher calorific value waste being destroyed.

This approach is significantly dif­ferent to the various National Incinerator proposals that have been discussed over the years, which only proposed to incinerate the intractable wastes.

However, it is also important to understand that the new MMBW In­tegrated Facility will be based on Vic­toria's waste streams. It should not be regarded as a replacement for a National Incinerator.

The MMBW has commissioned Maun-sell & Partners to undertake incinera­tion technology studies. The options outlined in this section have been developed by Maunsells in conjunction with their sub-consultant, Lurgi.

No decisions have yet been made about which option will finally be adop­ted However, the options are presen­ted to indicate the general trend of the investigations.

Alternative A1 : Rotary Kiln without Air Preheating

The simplest system for incineration provides for all wastes to be charged to a single rotary kiln incinerator. Because the waste stream may contain chlorin­ated solvents and small quantities of PCB's, the kiln is specified to operate with a 3 second residence time and 1200°C residence time in the after­burning chamber. Based on the antic­ipated heat contents of the waste materials, it is necessary to burn sup­plementary fuel to maintain the required 1200°C temperature.

Alternative A2: Rotary Kiln with Air Preheating

By the addition of a heat exchanger in

106

the flue gas stream, it is possible to pre­heat a portion of the combustion air to 500°C and thus eliminate the use of supplementary fuel (except for start­up). The elimination of supplementary fuel also reduces the volume of flue gas to be handled in the afterburning cham­ber and downstream: equipment. This results in substantial savings in the cost of these equipment items which actually lead to a nett cost reduction of approx. $0.3 million, despite the addition of an air preheater.

Alternative A3: Rotary Kiln with Waste Heat Boiler

Even with the addition of an air pre­heater, as provided for in Alternative A2. the flue gas has a temperature upstream of the scrubbing stage of around 600oC. This remaining heat content in the fine gas can be recovered by provid­ing a waste heat boiler which incor­porates the air preheater and reduces the flue gas temperature to around 250oC and produces approx. 20t/hour of steam. This steam could have signifi­cant commercial value depending on the final location of the facility.

Alternative A4: Rotary Kiln/Separate COMBUSTION Chamber

In Alternatives AI and A2, the rotary kiln afterburning chamber system has been designed for 1200oC and 3 sec residence time due to the presence of chlorinated solvents and PCB's. An alternative is to extract these difficult materials from the waste stream and burn them in a separate, smaller com-bustor designed for those more stringent conditions. As all these wastes are in liquid form, a directly fired combustion chamber may be used together wish its own afterburner. In this case, the rotary kiln and afterburner could be derated to 1000°C/1 sec. This allows consider­able savings due to the reduction of afterburner size (by almost 70 %) .

Due to the lower operating tempera­ture, it is also possible to operate with­out supplementary fuel and without the need for air preheating.

C O N C L U S I O N S

The purpose of this paper has been to set out the MMBWs proposals for In­dustrial Waste Management in Vic­toria, with particular emphasis on the use of an incinerator to treat a wide range of wastes.

While some decisions have yet to be taken about the incinerator con­figurations, it will be seen, that we have now made significant progress in de­veloping a safe and effective system to provide for Victoria's industrial wastes.

This paper outlines our esperience at the division of Applied Organic Chemis­try of CSIRO in the disposal of liquid waste, and how we are tackling the pro­blem, including what we have done already and what needs to be done in our particular program.

A research laboratory such as ours of necessity produces waste solvent of various sorts from the normal pro­cesses of purification of chemical pro­ducts by crystallization, chromatography and so on. About half of this solvent is chlorinated. Until about 18 months to two years ago, all waste solvent ws dis­posed of through normal commercial waste collectors or by dumping into a deep sand pit on site at Fishermen's Bend.

It was obvious to some of us that we should take more responsibility for the safe disposal of our own waste, and the only reasonable way to do this was by-high temperature incineration. On site at that time was the team which de­veloped PSZ. the partially stabilized zirconia ceramic which is now being commercialized for the world market. The furnaces for fusing the zirconia were designed by Bob Hughan and he was happy to help as design and build a small high temperature furnace for the destruction of waste solvent. Later Models were designed by Brian Williams, our own Engineer.

In Hue with accepted practice for the destruction of chlorinated compounds, we aimed for a residence time in the fur­nace of at least two seconds, and a minimum temperature of 1100oC. Exit gases would be scrubbed to remove hydrogen chloride.

The design eventually adopted was a simple rectangular furnace of firebrick, fired by liquid petroleum gas (LPG) of interior dimensions 25 cm x 30 cm x 200 cm high. The initial (Mark 1) model was down draft, but the present model is a simple up-draft construction with

Clean Air/August 1986 Voi. 20/3

baffles to increase turbulence and resi­dence time. Two burners are used in the positions shown, and the liquid waste is injected above the bottom burner.

The total set-up is shown in Figure 1. The effluent gases are drawn through stainless steel flue to a cooler, then to a scrubber. The scrubbing water removes hydrogen chloride which is the main end-product from the chlorine in chlori­nated organic compounds. Since the amount of chlorinated waste varies from time to time, we are in the process of installing automatic sensing of pH of the scrubbing tank and automatic neut­ralization with alkali. It is probably bet­ter to scrub with slightly alkaline water since we have noticed that with excess

NEW PRODUCT

NEW DIGITAL PLANIMETER CONNECTS TO EXTERNAL COMPUTER

Wild Leitz (Australia) Pty. Limited announce the release of a digitising planimeter offering, for the first time, the facility of transmitting the output to an external computer.

Planix 5000, made by Tamaya, Japan, is a development of the popular Planix 7 series of digitising planimeters, with the ability to measure length as well as area, displaying the output on a built-in LCD display panel.

An important feature of the new instrument is that it has a built-in output port, enabling the X-Y co-ordinates of the measuring head to be transmitted

oxygen present, traces of chlorine can be formed

Such a furnace can handle 25-50 kg of solvent per hourdepending on chlorine content and the heating value of the waste liquid, i.e., about 1 tonne per 24 hour day. It has certainly solved the waste solvent disposal problem of our Division, but we believe that it has wider applicatioa

Because of its relatively small size and ease of modular construction, it can be made mobile, i. e., mounted on a trailer or vehicle of some sort, towed to the site of waste generation and fired up, very quickly, then taken away. Such a scheme would eliminate the need to transport waste and therefore the dangers

continuously to external computers. The Planix 5000 features POINT

and STREAM modes, greatly sim­plifying the operation of the instrument

In POINT mode, there is no need to trace a straight line with precision. The operator simply plots the two end points of the line, and the built-in microp­rocessor does the rest

In STREAM mode, the operator traces the outline of curved lines. Measurements of both lengths and area are displayed at the touch of a button. Length can be measured with an accuracy better than- ±0.05 per cent; area to an accuracy better than ±0.1 percent

In designing the Planix series of digitising planimeters, Tamaya has eliminated the conventional measuring/ integrating wheel, with its associated problems of slip and wear.

The Planix 5000 makes use of two high-precision rotary encoders, which

associated with such transport We realize that it introduces other pro­blems, notably the possible need to obtain a clearance for every burn.

At this stage we would like to set up a Working Party, sponsored by the Vic­torian Department of Industry, Tech­nology & Resources and involving the regulatory authorities, ie. , the EPA and MMBW, to investigate the feasi­bility of such an approach using small, mobile, low-cost incinerators. If such an approach is considered worth pursu­ing, we have a work program already planned. We must know the chlorine content of each batch of waste- feed-we need to monitor oxygen uptake, temperature at various places within the unit, effluent composition in the gas stream, the scrubbing water and any solids that may accumulate. The unit needs to be foolproof and fully automated, so that any departure from acceptable working conditions shuts the unit dowa All of this is possible with modern in­strumentation. We need to try various types of firebrick lining and how they stand up to corrosion by high tempera­ture acid gases. We need to investigate a recent Swedish idea which indicates that injection of alkali with a chlori­nated feed reduces the temperature required for complete decomposition, reduces the formation of harmful diox-ins and reduced corrosioa All of these ideas would be contained in a properly constituted study.

The use of small, mobile, fully in­strumented incinerators will not solve all of our waste problems but it will solve many and it is an approach worth serious consideration.

generate the data to be processed by the built in microprocessor. The encoder rollers have special non-slip rings coated with a layer of very finely ground diamonds, eliminating wear problems, and guaranteeing a perfectly parallel and straight run on a flat surface.

The reliability and ease of the Planix 5000 are expected to extend the usage of planimeters into entirely new areas of measurement, as well as receiving wide acceptance from the traditional survey, scientific, engineering and car­tography users.

Further information about the Planix 5000 may be obtained from any office of Wild Leitz (Australia) Pty. Limited.

For further information please con­tact: Mr. Gunther Birk, Manager, Marketing and Technical Support, Wild Leitz (Australia) Pty. Ltd., P.O. Box 21, North Ryde, NSW 2113. Tel. (02)888 7122.

Clean Air/August 1986 Vol. 20/3

107

NEW BOOKS

Beit Filter Press Selection Guide now available The number of companies manufac­turing belt filter presses has increased rapidly in the U. S. and other countries. These companies offer a variety of features. The purchaser needs to deter­mine the relative advantages of such features as horizontal and inclinced gravity dewatering sections, cantilever designs, and tubular frame construc­tion. He needs to know the importance of different approaches to slurry dis­tribution, belt support, roller construc­tion, belt tensioning and other features.

A new report "Belt Filter Press Selection Guide" just published by The Mclvaine Co. provides comprehensive and up to date information on commer­cially available belt Filter presses. In addition to the comparison of basic features, the report covers recent de­velopments. Experience of suppliers is tabulated for each application from apple juice separation through coal refuse and municipal sludge of wine separation.

The report is divided into four sec­tions. The first section provides the comparative analysis of belt filter press features and vendor experience infor­mation. Section two contains informa­tion on specific belt filter press instal­lations and interviews with belt sup­pliers, Users and BFP manufacturers. Section three contains summaries of recent published and unpublished articles on belt filter presses with information on how to acquire the full copies. Sec­tion four provides information on sup­plies of belt filter presses, belts and polymers in the U.S. and Europe.

The report entitled Belt Filter Press Selection Guide is available for U.S. $70.00 per year from: The Mclvaine Company 2970 Maria Avenue North-brook IL 60062 U.S.A. 312 272-0010.

ADVANCED DESIGN OF VENTILATION SYSTEMS FOR CONTAMINANT CONTROL

by H.D. Goodfellow, Hatch Associates Ltd., and University of Toronto, Toronto, Canada (Chemical Engineering Monograpahs, 23).

Here, for the first time, is a authorita­tive technical reference book covering all aspects of state-of-the-art design of ventilation systems for contaminant control for a wide variety of manufac­turing and processing industries. The

author has played a key role in the de­velopment of the subject and this book is based on his extensive consulting ex­perience in the practical engineerig design of contaminant control systems world-wide, as well as his personal re­search work

The material is organized specifically for ease of understanding and contains all the technical information needed to develop cost-effective solutions for any type of contaminant in the workplace environment A unique feature is the development of recommended subject classifications for the ventilation field. For each type of ventilation system, the fundamental design equations are de­veloped from theoretical principles, and numerous examples are given of the practical application of these design equations to solving industrial ventila­tion problems. Another feature of the book that the reader will find extremely valuable is the use of a design method­ology based on the systems approach -an approach which represents a powerful design too! for professionals working in the contaminant control field.

Each chapter contains an extensive and current reference section which further enhances the usefulness of this important new book - a must for ven­tilation engineers, industrial hygienists, environmental engineers, safety experts, and researchers and consultants in the field. The logical progression from definitions, background fundamentals, and equipment specifications through to specific and specialized techniques makes this an ideal textbook for graduate level university courses.

CONTENTS: 1. Fundamentals. 2. Ventilation System Equipment- Design Parameters/Specifications. 3. Indus­trial Ventilation for Process Buildings. 4. Local Exhaust Ventilation - Dust Control. 5. Design of Ventilation Sys­tems for Fume Control 6. Specialized Ventilation Techniques. Appendices: Threshold Limit Values. Ventilation System Design Charts. Typical Tech­nical Specifications with Question­naires. Dust Control Design Charts. Electric Arc Furnace Fume System Desiga

Available from D.A. Book (Aust.) Pty. Ltd, 11-13 Station Street, Mitcham, Vic. 3132. 746 pages. ISBN 0 444 42546-2.

FLARE GAS SYSTEMS POCKET HANDBOOK K. Banerjee, N.P. Cheremisinoff and P.N. Cheremisinoff, Gulf Publishing Co., Houston, 1985. 133pp.

This A5 sized book (for the generously sized pocket) appears to be aimed both

at the designer responsible for the plan­ning of a gas flaring system and also at the refinery personnel responsible for operating and maintaining such a sys­tem. It is well-written and clear, well-structured and laid-out, and the illus­trations are appropriate and informa­tive. Care is taken to ensure that impor­tant technical terms are defined and explained and a list of the symbols used and their meanings is placed prominen­tly at the front of the book. References are comparatively few in number but this is not unusual in a handbook of this kind. My one big complaint about the book is that 19½ of the book's 133 pages are taken up by a table of unit conversions, many of which are utterly irrelevant to the subject matter of the book and some of which are exceedingly obscure: when did you in your technical tasks last concern yourself with con­verting "gills (British)'" t o " cubic cm"; "leagues" to "miles (approx)", "par-sees" to "kilometers"; or "scruples" to "grains"?

The main part of the book is com­prised of six chapters. The first of these provides an overview of flare systems, paying particular attention to the res­pective merits and shortcomings of the two main categories of flare systems, namely ground systems and elevated systems. Chapter two concerns itself with sources of gases needing to be flared; causes of overpressure are dis­cussed, methods for estimating likely vapour loads on the flare system are presented, and an illustrative worked example is given. In chapter three the design of gas collection systems is dealt with. Topics covered include types of safety valve, flare headers, construc­tion materials and line sizing. Relevant design formulae are provided, together with worked examples. The fourth chap­ter is concerned with the flare stack and associated equipment especially knock­out drums and sealing systems. Again relevant formulae and sample calcula­tions are presented. The penultimate chapter is devoted to general design considerations, for instance utility re­quirements, noise, controls, and start­up and shut-down procedures, while the final chapter is effectively an appen­dix, covering aspects of basic theory, references and the table of unit conver­sions referred to previously.

Overall, for engineers and other wishing to improve their knowledge and understanding of the design and opera­tion of flare gas systems this should prove a most useful and informative book.

M A . CONNOR

108 Clean Air/August 1986 Vol. 20/3

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Qanvene is the world's most advanced convention management computer system, which, combined with Qantas' unchallenged expertise in travel and related areas, can provide you with a wide range of convention options and packages.

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QPK3808

Esso. Getting on with the neighbours.

It was back in 1967 Esso would. But the seals felt differently. In fact the platforms are virtually first discovered oil in Bass Strait. The water around the platform fast reefs of steel. Vital oil that Australia needed. became their new home, the seal The oil in Bass Strait is needed

But the question was raised about population and other marine life by all of us. The seals need the effect on marine life in the area. continue to multiply healthily. Bass Strait. How would it be affected? This is because the Esso/BHP It's good to know that Esso and

Would the seals, for instance, platforms themselves attract a BHP have shown that oil production move away? variety of marine life and the seals and the environment can live

A lot of people thought they are taking advantage of this. happily together.

Energy for Australia