Annual Report of Air Pollution and Stone Conservation Laboratory

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ANNUAL REPORT OF AIR POLLUTION ANDSTONE CONSERVATION LABORATORY

2010Published by

Dy. Superintending Archaeological Chemist

Archaeological Survey of India

Air Pollution & Stone Conservation Laboratory

Agra Fort, Agra


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Principal Contributor

&Chief Editor

P.C. GuptaDy. Superintending Archaeological Chemist

Air Pollution Monitoring Team

D. Benerjee, ASAC

Abhilasha Singh, AAC

Ravindra Pachar, AAC

Stone Conservation Research Team

B.P. Nauni, ASAC

Akhilesh Bhadoriya, AAC

Edited By

Rohit Misra, AAC


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FOREWORD

Present-day Agras fame rests entirely upon the presence of the Taj Mahal.

However, the city is also home to a rich collection of lesser-known and seldom-

visited Mughal monuments, many of which are situated on the Yamuna riverfront

within a relatively short distance of each other.

Deterioration of the cultural heritage as a result of pollution and other similar

factors is still a real and topical issue. Though for Taj Mahal, Archeological Survey of

India has established specific strategies and action plans for regular monitoring and

long-term follow-up of conservation methods. For that, Ambient Air Quality

Monitoring Station was established at Taj Mahal in 1981 for the monitoring and

analysis of pollutants in the ambience air of Taj by Archeological Survey of India.

But, round the clock monitoring of air pollutants and meteorological parameters

throughout the year has been started since December 2000 as per the order of

Honorable Supreme Court.

This report presents air pollution data monitored during the year 2010. In the

compilation of this report, the annual average values for the earlier years have also

been incorporated with a view to enable the reader to have a full picture of the

environmental scenario in the ambience of Taj Mahal.

Place: Agra

Date: P. C. Gupta

Dy. Superintending Archaeological Chemist

Archaeological Survey of India

Air Pollution & Stone Conservation Laboratories

Agra Fort, Agra


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Contents

Section A:AIR QUALITY MONITORING WORK

1. Introduction 1

1.1. Cultural Heritage 1

1.2. Pollution threats on Heritage Properties 1

1.3. Taj Mahal and Its Conservation 4

2. Meteorology 72.1. Meteorological parameters 7

2.2. Wind Speed 9

2.3. Wind Direction 10

2.4. Relative Humidity 20

2.5. Temperature 23

2.6. Rain Fall 26

3. Deposition of Particulate 27

3.1. Dust pollution 29

3.1.1. Dispersion Mechanism and Effect 29

3.1.2. Dust Fall Measurement 30

3.1.3. Dust Fall pollution 30

3.2. Suspended Particulate Matter 40

3.2.1. SPM at Taj mahal 41

4. Gaseous Pollutants 44

4.1. Oxides of Sulphure 45

4.2. Oxides of Nitrogen 48

5. Sulphation Rate at Taj mahal & Sikandra 51

6. Current Scenario of Air Pollution at Taj Mahal 54


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Section B: STONE CONSERVATION RESEARCH WORK

1. Introduction 56

1.1. Setting Up of Stone Conservation Laboratory 57

2. Research Work 58

2.1. Petrographic Studies 58

2.1.1. Samples 58

2.1.2. Preparation of thin sections 59

2.1.3. Petrographic description 59

2.1.3.1. Inlayed Stones of Taj Mahal 59

2.1.3.2. Stone Sample of Sun Temple, Konark 62

3. Comprehensive Scientific Investigations on Itmad-Ud-Daulah 63

3.1. Photo-documentation 63

3.2. Weathering Problems 68

3.3. Material Used 72

3.4. Sample Collection 72

3.5. Stereomicroscopic Studies 74

3.6. TDS/Conductivity Measurement 77

3.7. Insoluble Inorganic matter 77

4. Present Status of Work 78

Other Activities of Air Pollution and Stone Conservation laboratory 78


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1. Introduction

1.1 Cultural Heritage

Culture is the evolution of human life in space and time. The monuments

remnants of the human creation of all the times form the prints, the signs, the

evidences, the strides of the human-beings progress within the time. Cultural values

created by our ancestors, and represent every sphere of their activities, including:

political, economic, cultural, industrial as well as their daily life. Cultural properties are

an indispensable part of our world; from them we obtain information about the history,

culture, ideas and technologies that we use as a basis for considering our present and

future, our society and culture. Thus, monuments form an undivided entirety with time

and place, with man, his surroundings and his history. These unique and

unprecedented fingerprints of human civilization form the natural and cultural heritage of

a place, of a country, of a people, the peculiar features of a nation which characterize its

identity.

The term heritagewas used for first time from experts in the early seventies, to

declare all the human creation with artistic features, which have been delivered to us as

hereditary asset, namely as heritage. In India we have a vast continuity of our cultural

heritage. It ranges from wonderful monuments to manuscripts, sculptures, paintings,

wood carvings etc.


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1.2 Pollution threats on Heritage Properties

Cultural heritage is continuously undergoing numerical strains: anthropogenic

and natural ones, from which the former can be anticipated, or prevented, whereas the

latter not. The result of these strains is the deteriorationof all the materials. In fact, there

is no material which is not to be downgraded.

Of the many types of cultural properties, the tangible cultural properties -

buildings, handicrafts, paintings, statues, ancient documents, antiquities, materials of

folk history and so on - are made of a variety of materials including metal, stone, wood,

textiles, paper and leather, or a combination of these materials. With the passage of

time and the effect of external factors such as the formation of mold, insect attack,

changes in temperature and humidity, ultraviolet rays and so on, materials will

deteriorate, gradually causing irreparable damages to the relic. This type of natural

deterioration of cultural properties can be prevented using traditional repair techniques

and through the application of chemical preservatives such as synthetic resins.

Therefore, cultural properties can be restored and protected in most circumstances.

However, in recent years the deterioration of cultural properties caused by

different forms of atmospheric pollution has become a serious problem. Various

atmospheric pollutants cause the corrosion, fading, discoloring or deterioration of the

materials from which these cultural properties are made. Atmospheric pollution

penetrates into many places and has an adverse affect on many types of cultural

properties. Now, more than ever, these cultural properties are in danger of destruction.


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Pollution of the natural environment is largely unintended and unwanted

consequences of human activities in manufacturing, transportation, agriculture and

waste disposal. High levels of pollution are largely a consequence of industrialization,

urbanization and the rapid increase of human population in modern times. Pollutants

are commonly classified according to the part of the environment primarily effected by

them, either by air, water or land. Sub-grouping depends on characteristics of the

pollutants themselves: chemical, physical, thermal and others. Many pollutants affect

more than one resource. The substances that pollute the atmosphere are either gases,

finely divided soils, or finely dispersed liquids aerosols. Five major classes of pollutants

are discharged into the air: carbon monoxide, sulphur oxides, hydrocarbons, nitrogen

oxides and particulates (dust, ash). Air pollution as an anthropogenic reason for

materials deterioration forms a problem of a great importance, because it has

catastrophic consequences, universally, in health, in the environment and in the cultural

heritage monuments and artifacts.

The resistance of stone to the weathering agents, natural or artificial is not linear

and the stone once depleted becomes much more prone to the action of pollutants. The

weathering behavior further becomes more complex in case of deposition of air borne

particulate contaminated with acidic gases and traces of heavy metals. The deposited

particulate matter which is not only aesthetically detractive but also hides decay, aging

forms a hard crust on stone surface, the carved surface and the niches that provide

better sink to the particulate and do not receive direct rain lashes are indicative of the

problem due to high levels of S.P.M. In such cases it is essential to carry out active

conservation measures by way of removing the accretion deposits and improving the


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surface resistance to the weathering action either by action of some polymeric coat or

by improving the surface characteristics. The active conservation measures using the

appropriate method, developed and evaluated in the laboratory, have yielded very

encouraging results in case of the Taj mausoleum.

The principle source of air pollution is the burning of fossil fuels, e.g., coal, oil and

derivatives of the latter, such as gasoline, in internal combustion engines or for heating

or industrial purposes. Once released into the atmosphere organic and inorganic

pollutants undergo a variety of complex interaction determined by physical and chemical

processes. Again, photochemical processes also play a role on organic and inorganic

pollutants. In these phenomena the atmospheric chemistry of a region and air quality

trends do not show a uniform trend due to the obvious role of complex photochemical

reactions coupled with related chemical reactions.

1.3 Taj Mahal and Its Conservation

There has been a long tradition in and awareness of the importance of cultural

heritage, especially immovable heritage, at the national level, in particular related to the

protection and restoration of architectural heritage like Taj Mahal. Indeed for many

centuries, there has been awareness of the importance of preserving built heritage, but

this idea of restoration really crystallized in the 19th century, these ideas being put into

practice.

Atmospheric pollutants and its relationship with heritage conservation are one of

the most important issues which concern us today. Asian countries possess the largest


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legacy of monuments and thus have a great potential for conservation measures as well

as heritage and culture issues. To further this concern technologist and archaeologist

the world over are interested in the healthy keep up monuments.

The Taj Mahal is a world heritage site, located in a predominantly agricultural

landscape, dotted with small lime kilns burning high-sulfur coals, and in an environment

conducive to frequent heavy dewfall. The construction is almost entirely of marble and

other decorative stones. The prospect of pollution-related damage to the Taj Mahal is of

considerable social and economic concern, and has generated a number of programs to

document pollution-related decay and to identify specific cause of observed damage.

Agra (2710N, 7805E) is located in north central India 200 km southeast of

Delhi. Two-thirds of its peripheral boundaries (SE, W and NW) are bounded by the

Rajasthan desert. The soil type is a mixture of sand and loam, containing excess of

salts. The city is about 169 m above the MSL and has semi-arid climate with

atmospheric temperature ranging between 11 to 48C (max.) and 0.7 to 30C (min.),

relative humidity between 25 95%, and average rainfall of about 650 mm per year. The

climate of Agra has been broadly divided into three seasons: winter (November to

February), summer (March to June) and monsoon (July to October). The prevailing

directions follow two distinct patterns: during monsoon winds are from W, NW, SW and

NE Sector, while during the rest of the seasons they are from W and NW sector.

The 10,400 sq km region covered under the TTZ has been categorized as a

sensitive zone because of the existence of many world Heritage Sites. Some important

urban centers, which come under the Taj Trapezium Zone, include Agra, Firozabad,


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Mathura, Bharatpur, Jalesar and Hathras. These are the primary growth centers of the

region. They influence not only the regional economy but also the environment. The

region is most fertile in the country. Besides the Taj Mahal, the TTZ includes two other

world heritage monuments the Agra Fort and Fatehpur Sikri. About two million

tourists visit Agra every year, making it a major source of revenue and foreign exchange

for the region. However, continuously rising environmental pollution has been the cause

of concern for the protection of Taj marble.

Over last few decades, the damage caused to the Taj Mahal by the pollution

created by various industrial, commercial and residential activities surrounding it has

been prompting the government of India, courts, activist groups and various donor

agencies to raise awareness about the threat and to develop programs to protect the

monument. In 1979, the Government of India (GOI) constituted a High Power

Committee (HPC) to protect the Taj Mahal monument from chemical corrosion and

degradation. Thereafter, no polluting industry was allowed to establish or expand in

Agra. Subsequently, there had been many environmental interventions. They include

installation of air pollution control units by 173 industries (out of 265) by 1994 and some

others especially between 1996 and 2000 have resulted in overall improvement in

environmental quality of Agra city during that period.

The Ambient Air Quality Monitoring Station was established at Taj Mahal in 1981

for the monitoring and analysis of pollutants in the ambience air of Taj by Archeological

Survey of India. But, round the clock monitoring of air pollutants and meteorological

parameters throughout the year has been started since December 2000 as per the

order of Honorable Supreme Court.


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2. Meteorology

The beginnings of meteorology can be traced back to ancient India, as the

Upanishads contain serious discussion about the processes of cloud formation and rain

and the seasonal cycles caused by the movement of Earth around the sun.

Varahamihiras classical work Brihatsamhita, written about 500 A.D., provides clear

evidence that a deep knowledge of atmospheric processes existed even in those times.

The atmospheric conditions determine the behavior of pollutants after they leave

the source or sources until they reach receptors, Such as people, animals, plants and

buildings. Therefore, knowledge of meteorological and characteristics of a study area

are of utmost importance. Transport and diffusion of the pollutants to atmosphere is

governed by Meteorological factors. Meteorology study may be classified under macro

and micro meteorological heads. Micrometeorology meaning study of minute variations

in atmospheric conditions confined to an area of a few square kilometers and up to an

elevation of 500 to 1000 meters in the atmosphere governs the transmission and

diffusion of air pollutants.

2.1 Meteorological Parameters

These have been grouped under two heads viz the primary and the secondary.

Amongst the primary meteorological parameters are wind speed, wind direction and

atmospheric stability. The secondary factors include ambient temperature, humidity,

precipitation, solar radiation, pressure and visibility. The primary factors are responsible

for the dispersion and dilution, whereas secondary factors first affect the primary


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parameters thus altering transmission of air pollutants. This grouping of primary and

secondary parameters will also depend on particulate study and/or site. For example for

site affected by smog, solar radiation may be taken as primary parameter.

The wind direction is another important factor as the affect of emissions at a

particular area is dependent upon the direction of wind from the source. Even in our

most polluted cities where there are heavy industries, there are frequent periods when

the atmospheric air is quite clear and transparent. These frequent fluctuations are not

caused by gross changes in the emission of local pollutants but rather are a function of

variation in the meteorological conditions.

A numerical scale for the estimation of wind force/speed and its effect on

common object is given below


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2.2 Wind Speed

This is very important determines the rates of dilution and transport of air

pollutants. The travel time is important in that, it determines the amount of time; the

pollution is exposed to the above meteorological factors before coming into contact with

receptors.

The second effect of wind speed is on dilution of the pollutant in the down wind

direction. The dilution of air pollutants released from a source is directly proportional to

wind speed or the down wind concentration of air pollutants is inversely proportional to

wind speed.

Wind speed is affected by a number of factors and situations, operating on

varying scales (from micro to macro scales). These include the pressure gradient,

Rossby waves and jet streams, and local weather conditions. There are also links to be

found between wind speed and wind direction, notably with the pressure gradient and

surfaces over which the air is found.

The wind speed in the ambience of Taj is being measured with wind monitor

WM-271 on hourly basis. The wind rose diagram obtained from wind monitor provides

information about monthly average wind speed (in wind speed ranges of 1.6 Km/h, 5.0

Km/h, 12.0 Km/h, 20.0 Km/h, 29.0 Km/h & above 29.0 Km/h)


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2.3 Wind Direction

The wind direction will have an important influence on the expected weather. You

can often be given a wind direction and you will have a pretty good idea of how the

weather will change and what weather can be expected with that wind direction.

The typical wind direction that a location has for a certain time of the year is

called the prevailing wind. When the wind is from the prevailing direction then the

weather is generally typical. When the wind shifts away from the prevailing direction

then it often indicates atypical or changing weather.

The wind direction in the ambience of Taj is being measured with wind monitor

WM-271 on hourly basis. The wind rose diagram obtained from wind monitor provides

information about percent wind direction (in 16 components as E, EN-E, N-E, NN-E, N,

NN-W, N-W, WN-W, W, WS-W, S-W, SS-W, S, SS-E, S-E, ES-S). Turbulence and flow

of wind primarily govern the dispersion of pollutants emitted from the source.

The data related to all the 16 components of wind direction have been compiled

in Table 2.1 & 2.2 and their graphical representation is given in wind rose diagrams.

During the year 2010 the wind rose diagram has been drawn in respect of wind speed

and wind direction through the wind monitor WM 271.

During the year 2010, the wind predominantly blew from North west, West north-

west, West & West south-west directions to South east, East south-east, East & East

north-east directions respectively.


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Table 2.1: Wind Direction (Percent Average Component) For the Year 2010

WindDirection/

MonthE EN-E N-E NN-E N NN-W N-W WN-W

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

4.17

4.35

5.80

1.94

6.89

4.89

19.4

14.3

9.17

9.23

3.88

0.68

2.78

3.11

3.72

1.79

3.03

4.17

6.02

4.72

3.49

2.86

1.87

1.37

5.98

3.42

2.90

2.69

5.79

4.17

6.02

4.72

2.76

4.61

1.43

3.44

4.03

2.64

0.96

1.64

3.72

4.02

4.93

1.11

5.53

1.75

1.58

1.37

1.66

1.71

1.51

2.24

3.31

3.45

1.91

0.69

4.07

1.27

1.43

2.06

3.19

3.26

4.55

1.64

7.03

7.19

2.32

0.97

6.40

4.14

4.31

5.24

6.67

9.79

9.25

5.23

6.48

6.47

2.32

0.97

4.36

8.43

4.02

6.48

6.25

6.37

7.87

14.0

6.20

10.2

1.23

1.52

7.27

10.1

5.46

7.44


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Table 2.2: WIND DIRECTION (PERCENT AVERAGE COMPONENT) FOR THE YEAR2010

WindDirection/

MonthW WS-W S-W SS-W S SS-E S-E ES-E Calm

Air

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

6.25

14.1

17.8

19.9

8.13

14.9

3.01

3.05

6.40

6.68

13.2

11.3

4.45

6.53

8.01

18.2

5.51

11.9

4.10

6.25

9.60

4.93

6.90

6.89

0.55

2.64

1.65

6.88

0.41

3.02

0.13

2.08

3.49

0.79

1.58

1.51

0.0

0.0

0.0

0.0

0.0

0.14

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.0

0.29

0.0

0.0

0.13

0.13

0.0

0.0

0.0

0.13

0.27

0.31

0.0

0.0

0.0

0.28

0.54

0.13

0.0

0.0

0.0

0.0

0.0

0.31

0.0

0.14

1.37

0.43

0.82

0.97

0.0

0.0

0.0

0.0

0.55

2.48

1.38

0.89

13.9

2.87

14.7

12.7

4.22

5.09

1.15

0.41

53.12

38.88

34.60

22.15

28.13

21.58

32.19

45.55

33.18

39.96

53.09

51.58


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Monthly Wind-rose Diagram For the year 2010

January 2010

February 2010


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March 2010

April 2010


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May 2010

June 2010


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July 2010

August 2010


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September 2010

October 2010


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November 2010

December 2010


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2.4 Relative humidity

The measurement of humidity is of secondary importance in most air pollution

studies. The hygrometric state of the atmosphere in terms of relative humidity is

expressed as the ratio of the amount of water vapor present in the atmosphere to the

amount of water required to saturate it at that temperature. The values are usually given

as percent.

The relative humidity in the immediate environment of the stone plays an

important role in influencing the weathering action of various pollutants. The role of

humidity are in aggravating, the rusting of iron dowels, leaching of cementing material

and even allowing the action of SO2 through dry deposition. Though the porosity of the

stone and the binding matrix are significant parameters which are responsible for

weathering of stone, the ingress of water through cracks and crevices in case of stone

having least porosity may cause more danger than stone having high porosity. In this

context, the studies reported earlier show that humidity determination on various litho

types have shown that in marble which has a very low porosity, humidity rapidly diffuses

in the whole material. Sand stone having much high porosity than marble absorbs

greater amount of water which however diffuses more slowly within the stone.

Relative humidity has been recorded with wind monitor WM-271 on hourly basis.

The data of relative humidity recorded in the ambience of Taj Mahal have been

compiled in Table 2.3 & Figure 2.1.

The maximum relative humidity was recorded as 100.0 % in the month of

September & December. The minimum relative humidity was recorded as 5.0% in the

month of April. The Maximum variation in relative humidity in a day was recorded as

65.3% in the month of January & December. The Maximum monthly average variation

in relative humidity was recorded as 46.0% in the month of February.


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Table 2.3: Relative Humidity at Taj Mahal for the year 2010

Month Relative Humidity (%)Max. Min. Variation

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

99.5

95.4

81.2

56.0

91.0

78.5

99.0

98.2

100

95.5

99.0

100

30.2

20.1

8.0

5.0

14.3

17.2

39.1

44.0

34.1

27.0

32.1

28.1

69.3

75.3

73.2

51

76.7

61.3

59.9

54.2

65.9

68.5

66.9

71.9


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Figure 2.1: % Relative Humidity at Taj Mahal for the year 2010


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2.5 Temperature

The maximum temperature in air pollution studies may be used to estimate the

maximum mixing depth for the day if a temperature profile is available. In addition, the

daily range of temperature may be used to calculate heating degree day values. The

wide temperature fluctuations causing thermal movement in the building materials

results in the decay process when experienced over longer periods. The temperature

inversion retards the diffusion rate of air pollutants which ultimately results in direct or

indirect interaction between building materials and air pollutants.

Temperature has been recorded with wind monitor WM-271 on hourly basis. The

data of atmospheric temperature recorded in the ambience of Taj Mahal has been

compiled in Table 2.4 & Figure 2.2. The Maximum temperature was recorded as 45.40C

in the month of May while minimum temperature was recorded as 6.20C in the month of

January. The maximum variation in temperature in a day was recorded as 17.3 0C in the

month of January. The maximum monthly average variation in temperature was

recorded as 13.6 0C for the month of March.


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Table 2.4: Temprature at Taj Mahal for the year 2010

Month Temperature (0C)Max. Min. Variation

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

28.3

31.4

40.1

43.3

45.4

43.6

39.1

38.4

35.3

35.6

31.6

25.6

6.2

12.0

16.2

23.0

22.2

24.0

24.2

24.3

22.2

18.6

15.0

9.0

22.1

19.4

23.9

20.3

23.2

19.6

14.9

14.1

13.1

17

16.6

16.6


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Figure 2.2: Temperature at Taj Mahal for the year 2010


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2.6 Rain Fall

Rain is liquid precipitation, as opposed to non-liquid kinds of precipitation such as

snow, hail and sleet. In meteorology, rainfall typescan include the character or phase of

the precipitation which is falling to ground level. There are three distinct ways that rain

can occur. These methods include convective, stratiform, and orographic rainfall.

Convective precipitation is generally more intense, and of shorter duration, than

stratiform precipitation. Precipitation can also fall in two phases, either liquid or solid.

Liquid forms of precipitation include rain and drizzle. Rain or drizzle which freezes on

contact within a subfreezing air mass gains the preceding word of freezing, becoming

known as freezing rain or freezing drizzle. Frozen forms of precipitation include snow,

ice needles, sleet, hail, and graupel. Precipitation intensity is determined either by rate

of fall, or by visibility restriction.

Rain fall is also measured with WM-271 on hourly basis. The intensity of rain

largely influences the impact of acidic pollutants on calcareous stone. In case of stone

which is exposed and regularly washed by rains, the accretion deposits along with the

resultant products may be washed away.

The maximum Rain fall was recorded as 247.00 mm in the month of September,

where as the minimum rain fall was recorded as 4.00 mm in the month of January. It

was also noticed that there was no rain during the month of March, April, October &

December. The total rain fall during this year was recorded as 669.90 mm.


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3. Deposition of Particulates

Particulate matter (PM) is the term used for a mixture of solid particles and liquid

droplets suspended in the air. These particles originate from a variety of sources, such

as power plants, industrial processes, and diesel trucks, and they are formed in the

atmosphere by transformation of gaseous emissions. Their chemical and physical

compositions are depending on location, time of year, and weather. Particulate matter

is composed of both coarse and fine particles. Dispersion of particulates emitted

from a stack differs from that of pollutant gases that settle toward the earths surface,

they are not re-entrained in the atmosphere by the wind. Particles may also be removed

by wash out and rain out and impaction on surface of trees, structures and other objects

in contact with the air. The time of removal varies with particle size, height above the

surface and the meteorological factors that transport the particles. Some particles are

airborne only a very short time, (measured in seconds) while others remain airborne for

long periods (upto years), such as the very small fall out ash injected into the

stratosphere by nuclear explosions or the small dusts from the eruption of volcanoes.

Impaction is quite important in the removal of small particles from the

atmosphere, especially those particles small enough to prevent effective settling. These

particles are also resistant to wash out. The velocity needed for impaction is given to the

particles by air currents and for very small particles (0.2 m) by Brownian motion. The

efficiency of removal depends upon the diameter of the particle, the characteristic length

(diameter) of the impaction surface, and the relative velocity between the particle and

the surface. The most effective impaction occurs when an aerosol is blown through tree


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leaves and grass or weeds. Impactive removal of particles from the air causes the

vertical and even the overhead surfaces of structures to become dirty.

Particulate matter (dust) comes in great varieties of size, grain loading, shape,

chemical composition, specific gravity, bulk density, friability, stickiness, resistivity,

wettability, cohesiveness etc. Inview of these variables, different types of particulates

have different meanings and the most common among them may be classified as

follows:-

Grit: Solid particles suspended in air with a diameter over 500 m.

Dust: Solid particles suspended in air with a diameter between 0.25 m- 500 m.

Smoke: Gas-borne solids with particles usually less than 2 m in diameter.

Fumes: Suspended solids in air less than 1.0 m in diameter normally released from

chemical or metallurgical processes.

Mist: Liquid droplets suspended in air with a diameter of less than 2.0 m.

Aerosols: Aerosols refer to solid or liquid particles of microscopic size (smoke, fog or

mist). Broadly speaking Aerosols fall into four classifications: 1) Sprays; 2) Mists; 3)

Dust; 4) Fumes. Liquid droplets suspended in air, greater than 10 m in size are defined

as sprays, those less than 10 m as mists. Similarly submicron solid particles

suspended in air are referred to as fumes and those greater than 1 m as dusts.


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3.1 Dust Pollution

The Dust consists of particles in the atmosphere that arise from various sources

such as soil dust lifted up by wind (an Aeolian process), volcanic eruptions, and

pollution. Dust in homes, offices, and other human environments contains small

amounts of plant pollen, human and animal hairs, textile fibers, paper fibers, minerals

from outdoor soil, human skin cells, the remains of burnt meteors and many other

materials which may be found in the local environment.

3.1.1 Dispersion Mechanism and Effect

The dust pollution may be due to natural blowing winds or emission from industries or

other sources.

The soil is easily picked up by the strong preventing winds. The coarser material is

drifted along close to ground to be piled along fences, hedges, buildings and other

obstacles. The finer dust being swept in to the air gives rise to blinding destructive dust

storms. Blown sand acts as a powerful abrasive agent. The effect on rock surface is far

greater if it is continuously exposed to natural sand blasting for a long period of time.

Large solid particles with a diameter of over 50 m are collectively visible in the air and

settle out fairly quickly so that they are not a long term pollution hazard. The grit and

dust of the kind collected in gauges used for the measurement of deposited on the

ground, on the roofs, window sills and other ledges of buildings and on other structures

mostly within a few kilometers of the points of discharge into the air. The larger sizes

over 10 m diameter fall near the sources of emission and the smaller particles are

carried further before being deposited. Consequently, stone work and clay quarries,

cement works, brick works often cause despoliation of the surrounding land. Dust fall

particles because of their large size are offensive to the visual sense and constitute a

nuisance.


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The abrasion due to soil particles depends on the size of the dust. The particles

moving with blowing winds when strike with the stone surface, their kinetic energychanges to potential energy and that potential energy and that potential energy grooves

the surface at striking point on continuous hammering.

The grit, dust and smoke in thickly populated industrial areas are heavily

contaminated with sticky soot and tarry matter. Such particles are often damp or wet

with atmospheric moisture or rain; they readily stick to surfaces with which they come

into contact and not easily removed. In addition, the particulate matter when moist or

wet absorbs SO2 from the contaminated air and the oxide is converted to sulphurous

and sulphuric acids. The affect of these acids is of chemical nature.

3.1.2 Dust Fall Measurement

The dust fall rate is measured by using standard recommended apparatus

(Dust Fall Jar) by gravimetrically in the nearby atmosphere of Taj Mahal, Agra Fort and

Sikandra on monthly basis. The values recorded for dust fall rate along with its pH,insoluble inorganic, organic and water soluble components.

3.1.3 Dust Fall Pollution

Dust fall rate was measured at Taj Mahal , Agra Fort and Sikandra and the data

obtained have been compiled in Table 3.1, 3.2, 3.3 & 3.4 Figure 3.1 ,3.2, 3.3, 3.4 & 3.5.

The maximum value of Dust fall rate at Taj Mahal, Agra Fort and Sikandra were

measured as 12.19 MT/Km2 /month in the month of June, 14.36 MT/Km2 /month in the

month of December, 9.08 MT/Km2 /month in the month of November respectively. The

minimum value of Dust fall rate at Taj Mahal, Agra Fort and Sikandra were measured as

2.99 MT/Km2 /month in the month of December, 2.14 MT/Km2 /month in the month of

August, 3.25 MT/Km2/month in the month of December respectively.


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Table 3.1: Dust Fall rate (MT/Km2/Month) at Taj Mahal , Agra Fort & Sikandra forthe year 2010

Month Taj Mahal Agra Fort Sikandra

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

7.68

5.79

7.16

6.24

11.65

12.19

8.78

5.26

6.41

5.66

8.97

2.99

6.31

5.72

6.50

6.49

8.50

10.33

5.52

2.14

2.24

4.52

7.59

14.36

3.38

3.50

6.56

6.03

6.52

6.74

6.31

6.05

3.61

7.40

9.08

3.25


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Figure 3.1: Dust Fall Rate (MT/Km2/Month) at Taj Mahal, Agra Fort & Sikandra for

the year 2010


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Table 3.2: Dust fall rate and its components at Taj Mahal for the year 2010

Month pH TotalInsolubleMatter (%)

VolatileMatter

(%)

WaterSolubleDust (%)

InsolubleInorganicMatter (%)

TotalInorganicMatter (%)

Dust Fall Rate(MT/Km

2/month)

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

7.0

7.0

6.2

7.7

6.9

7.5

7.5

6.9

7.0

7.2

7.5

7.7

8.47

18.70

9.0

22.10

23.11

16.11

15.58

24.65

9.57

17.28

12.45

31.27

6.41

18.05

7.74

20.41

21.50

14.05

14.23

23.90

7.71

16.08

10.95

28.52

91.53

81.30

91.00

77.90

76.89

83.89

84.42

75.35

90.43

82.72

87.55

68.73

2.06

0.65

1.26

1.69

1.60

2.06

1.35

0.75

2.46

1.20

1.50

2.75

93.59

81.95

92.26

79.59

78.50

85.95

85.77

76.10

92.89

83.92

89.05

71.48

7.68

5.79

7.16

6.24

11.65

12.19

8.78

5.26

6.41

5.66

8.97

2.99


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Table 3.3: Dust fall rate and its components at Agra Fort for the year 2010


VolatileMatter

(%)





2/month)

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

7.0

7.0

6.8

7.7

7.5

7.5

7.7

6.5

6.5

6.96

6.80

7.2

12.83

16.30

10.70

31.08

23.35

16.06

29.24

59.79

24.80

18.90

13.78

17.76

9.51

14.55

8.44

26.76

20.36

12.67

21.53

57.41

19.32

15.89

12.70

17.29

87.17

83.70

89.30

68.92

76.65

83.94

70.76

40.21

75.20

81.10

86.22

82.24

3.32

1.75

2.26

4.32

2.99

3.39

7.69

2.38

5.48

3.00

1.08

0.47

90.49

85.45

91.56

73.24

79.64

87.33

78.47

42.59

80.68

84.11

87.30

82.71

6.31

5.72

6.50

6.49

8.50

10.33

5.52

2.14

2.24

4.52

7.59

14.36


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Table 3.4: Dust fall rate and its components at Sikandra for the year 2010


VolatileMatter

(%)





2/month)

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

6.5

7.5

6.0

7.5

7.2

7.0

7.2

6.7

6.8

6.78

7.20

7.6

7.54

22.18

7.07

25.39

26.63

16.57

23.77

25.98

13.75

11.54

13.52

68.29

4.69

21.11

4.57

22.29

24.98

9.11

44.84

24.56

10.19

10.17

12.43

66.03

92.46

77.82

91.21

74.61

73.37

83.43

76.23

74.02

86.25

88.46

86.48

31.71

2.85

1.07

2.50

3.10

1.65

7.46

1.35

1.40

3.56

1.38

1.09

2.26

95.31

78.89

95.43

77.71

75.02

90.89

77.57

75.42

89.81

89.83

87.57

33.97

3.38

3.50

6.56

6.03

6.52

6.74

6.31

6.05

3.61

7.40

9.08

3.25


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Figure 3.2: % Total Insoluble Matter at Taj Mahal, Agra Fort & Sikandra for the

year 2010


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Figure 3.3: % Volatile Matter at Taj Mahal, Agra Fort & Sikandra for the year 2010


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Figure 3.4: % Water Soluble Matter at Taj Mahal, Agra Fort & Sikandra for the year

2010


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Figure 3.5: % Total Inorganic Matter at Taj Mahal, Agra Fort & Sikandra for the

year 2010


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3.2 Suspended Particulate Matter

Suspended particulate matter (SPM) in air generally is a complex, multi-phase

system of all airborne solid and low vapor pressure liquid particles having aerodynamic

particle sizes from below 0.01-100 m and larger.

Particulate in a stack effluent may because of their differing physical properties,

have motions different from the gaseous components. The greater mass density of

particulates results in gravitational forces which cause a down ward component of

motion. The effect of gravitational forces is generally identified by free-fall (settling,

terminal) velocity of a particle in a motionless body of air. This depends on particle size,

mass density and configuration as well as mass density and viscosity of the ambient air.

The term particulate refers to all atmospheric substances that are not

gaseous. They can be suspended droplets of solid particles or mixtures of two.

Particulate can be composed of inert or extremely reactive materials ranging in the size

from 100 m to 0.01m. The reactive material may further oxidize or may react

chemically with the environment. Particulate of the size less than 10 m are termed as

suspended particulate matter. Particulate from soils and minerals primarily contain

calcium, aluminum and silicone compounds. Organic compounds are released into the

atmosphere mainly by the processing and use of petroleum products. The damage

caused by the pollutants is well known phenomenon. Particulate such as soot, dust and

fumes damage painted surfaces, fabrics & buildings. Due to their abrasive nature,

particulate can cause damage to exposed surfaces when they are driven by wind at

high velocities.


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3.2.1 Suspended Particulate Matter at Taj Mahal

At Ambient Air Quality Monitoring Station of Taj Mahal, the sampling of

S.P.M. is being carried out on 8 hour bases on everyday of month by employing High

Volume Sampler (HVS). The glass micro fiber filter paper has been used for the

sampling of S.P.M.

The data obtained have been compiled in Table 3.5 & Figure 3.6. The maximum

concentration of S.P.M. for a day was estimated is 627.94 g/m3 in the month of

November while minimum concentration for a day was estimated is 10.30 g/m3 in the

month of September. The maximum monthly average concentration of S.P.M. was

determined is 354.15g/m3 for the month of April while minimum monthly average

concentration was determined is 50.94g/m3 for the month of August. The annual

average concentration was calculated is 229.87g/m3, which is slightly decreased as

compare to previous five consecutive years, i.e. 2005, 2006, 2007, 2008 & 2009. As

usual, it was observed that the monthly average concentration remained below the safe

limit in the month of August & September while rain was occurred and then started

increasing and finally estimated high during winter season i.e. in the month of

December. The Thermal inversion and calm condition in atmosphere were responsible

to increase the concentration of S.P.M. in ambient air at winter season.


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Table 3.5. Concentration of S.P.M. (g/m3) in the ambience of Taj Mahal for theyear 2010

Month S.P.M. (g/m3)

Max. Min. Avg.

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

304.82

380.64

436.39

499.99

569.85

384.02

315.80

77.29

250.27

485.28

627.94

518.18

135.15

95.46

224.75

254.88

159.35

108.50

35.93

26.18

10.30

117.93

79.92

205.13

210.12

228.57

311.99

354.15

303.18

259.76

101.54

50.94

81.61

266.95

288.05

301.54


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Figure 3.6: Concentration of SPM (g/m3) in the ambience of Taj Mahal for the

year 2010


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4. Gaseous Pollutant

Gaseous pollutants consist of atoms, molecules and include harmful gases,

which can freely mix with air without settling down. Some examples of gaseous

pollutants of air are carbon monoxide, carbon dioxide, sulphur dioxide, hydrogen

sulphide, nitrogen oxides and hydrocarbons. The gaseous pollutants which are directly

released into the atmosphere as a result of direct anthropogenic activities are classified

as primary pollutants. These are mostly the products of combustion of fossil fuels

(carbon dioxide, carbon monoxide, sulphur dioxide, oxides of nitrogen etc.), sulphurdioxide is produced during combustion of fossil fuels because such fuels always contain

some amount of sulphur. This is an acidic gas and finally gets converted to sulphuric

acid in the atmosphere which is responsible for the Acid Rain. Acid rain is particularly

harmful for vegetation as well as heritage monuments because of their acidic nature. As

an example, coal with 1.5 % sulphur by weight when burnt in a power station gives a

flue gas containing between 2-3 gm-3 of oxides of sulphur or in the region of 0.1 % by

volume. Among the oxides of sulphur, only SO2 and SO3 are of significant importance

as gaseous air pollutants. Of the sulphur oxides, more than 95% by volume is SO2 and

less than 5 % is SO3. In the atmosphere, SO2 gets oxidised to SO3 which in the

presence of water forms sulphuric acid.

The concentration of SO2 to be found in the atmosphere is governed not only by

the number of size of local sources but by other factors such as stack height and

meteorological parameters influencing the diffusion and dispersion pattern of gaseous

pollutants.

Another gaseous pollutant that is of significant destructive action is oxides of

nitrogen (NOx). These are products of high temperature combustion of fossil fuels.

Automobile emission is the main contribution of NOx in the urban atmosphere followed

by emission of thermal power plants. NOx is primarily responsible for photochemical

smog formation in the metropolitan areas.


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4.1 Oxides of Sulphur

The most important oxide emitted by pollution sources is SO2. Sulphur dioxide is a

colourless gas, moderately soluble in water and forms weakly acidic sulphurous acid. In

a polluted atmosphere, SO2 reacts photo-chemically or catalytically with other pollutants

or normal atmospheric constituents to form SO3, H2SO4 and salts of H2SO4. Sulphur

dioxide is mostly responsible for metallic corrosion. Sulphuric acid mist in the

atmosphere causes deterioration of structural materials such as marble and lime stone

by forming precipitate of their constituents. Many priceless marble sculptures and

buildings have suffered damage in the last 30 years or so as a result of increased

concentration of SO2 in the atmosphere.

Sulphur dioxide is monitored and analyzed by Modified West & Gaeke

method using Sequential Air Sampler (SAS) on 4 h basis. Tetra chloro mercurate (TCM)

is used as absorbing reagent for SO2. The concentration of SO2 is then measured

through spectrophotometer at specific wavelength 560 nm.

The data showing the concentration of SO2 in the ambience of Taj Mahal has been

compiled in Table 4.1 & Figure 4.1. The maximum concentration of SO2 for a day was

estimated as 9.03 g/m3 in the month of April while minimum concentration of SO2 for a

day was estimated as 3.00 g/m3 in every month of the year. The maximum monthly

average concentration was calculated as 4.60 g/m3 for the month of April while

minimum monthly average concentration was calculated as 3.00 g/m3 for the month of

July. The annual average concentration was calculated as 3.41g/m

3

. Both, monthlyaverage and annual average concentration were observed well below the safe limit

prescribed for sensitive zone i.e. 30g/m3 and 15g/m3 respectively.


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Table 4.1. Concentration of SO2 (g/m3) in the ambience of Taj Mahal for the year

2010

Month SO2 Concentration (g/m3)

Max. Min. Avg.

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

6.85

4.37

5.17

9.03

4.39

4.19

3.01

3.29

5.62

3.90

7.47

7.71

3.00

3.00

3.00

3.00

3.00

3.00

3.00

3.00

3.00

3.00

3.00

3.00

3.23

3.26

3.46

4.60

3.22

3.08

3.00

3.03

3.22

3.13

3.71

3.93


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Figure 4.1: Concentration of SO2 (g/m3) in the ambience of Taj Mahal for the year

2010


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4.2 Oxides of Nitrogen

Out of seven oxides of nitrogen, only three N2O, NO & NO2 are formed in

appreciable quantities in the atmosphere. NO& NO2 are analysed together in air and are

referred as NOx. Nitrogen dioxide in the atmosphere converts into nitrous and nitric acid

in the presence of moisture. These acids impart corrosive effects on metal species. The

CaCO3 content of marble on reaction with nitrogen acids converts into precipitate of

calcium nitrate, thus causing deterioration on marble surfaces.

NO2 is determined by Jacob & Hochneiser or Sodium-Arsenite method. Sampling

of NO2 has also been carried out by Sequential Air Sampler on 4 h basis. Alkaline

sodium arsenite solution is used as absorbing reagent. The concentration of oxides of

Nitrogen is determined through spectrophotometer at specific wavelength 540 nm.

The data showing the concentration of NO2 in the ambience of Taj Mahal has been

compiled in Table 4.2 & Figure 4.2. The maximum concentration of NO2 for a day was

estimated as 20.78 g/m3 in the month of November while minimum concentration of

NO2 for a day was estimated as 3.00 g/m3 for the month of July. The maximum

monthly average concentration was calculated as 13.42 g/m3 for the month of March

while minimum monthly average concentration was calculated as 4.34 g/m3 for the

month of July. The annual average concentration was calculated as 8.27 g/m3. In this

year, monthly average and annual average concentration were observed below the safe

limit prescribed for sensitive zone.


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Table 4.2. Concentration of NO2 (g/m3) in the ambience of Taj Mahal for the year

2010

Month NO2 Concentration (g/m3)

Max. Min. Avg.

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

16.73

11.83

20.67

13.73

12.08

9.34

6.60

12.51

12.18

17.22

20.78

18.84

3.60

3.64

8.21

3.98

3.09

3.17

3.00

3.93

3.20

3.67

6.83

7.21

8.02

6.64

13.42

7.90

6.30

5.75

4.34

7.64

6.97

8.04

12.53

11.64


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Figure 4.2: Concentration of NO2 (g/m3) in the ambience of Taj Mahal for the year

2010


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5. Sulphation Rate at Taj Mahal & Sikandra

Sulphation rate is referred as rate at which sulphur dioxide gets converted into

sulphur trioxide in the atmosphere. Being a reactive species SO3 forms sulphuric acid

under favorable conditions. The formation of such kind of acid mist or sulphate bearing

particulate when strikes with the monuments and building results in erosion and

corrosion of the surface. A glass test tube having a area of 100 cm2 is wrapped with a

cotton gauge soaked in a solution of weighed quantity of lead dioxide in gum

tragacanth. The test tube is kept in open atmosphere for one month. Lead dioxide

reacts with SO3 present in the atmosphere for one month. Lead dioxide reacts with SO3

present in the atmosphere to produce PbSO4. Lead sulphate is then estimated as

barium sulphate by measuring transmittance at 420 nm. The rate of conversion of SO2

into SO3 is then calculated.

The data showing the Sulphation rate have been compiled in Table 5 & Figure 5.

The maximum value of sulphation rate for Taj Mahal and Sikandra was determined as

0.0459 gmSO3 /m2 /day and 0.0816 gmSO3 /m

2 /day for the month of May and March

respectively. The minimum value of sulphation rate for Taj Mahal and Sikandra was

determined as 0.0164 gmSO3/m2 /day and 0.0086 gmSO3 /m

2 /day for the month of

March and February respectively.


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Table 5. Sulphation rate (gm SO3/m2/day) at Taj Mahal & Sikandra for the year

2010

Month Taj Mahal Sikandra

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

0.0357

0.0374

0.0164

0.0444

0.0459

0.0322

0.0250

0.0258

0.0272

0.0166

0.0239

0.0172

0.0148

0.0086

0.0816

0.0319

0.0349

0.0335

0.0290

0.0166

0.0172

0.0209

0.0341

0.0435


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Figure 5: Sulphation Rate (gmSO3/m2/day) at Taj Mahal & Sikandra for the year

2010


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6. Current Scenario of Air Pollution at Taj Mahal

The annual average concentration of S.P.M., SO2 & NO2 for last seven years

tabulated below which reflect the clear picture regarding air quality scenario in the

ambience of Taj Mahal, Agra.

On the basis of above observation it can be concluded that the environmental status

has slightly improved since early 2006. As we have noticed that the concentration of

gaseous pollutants as well as concentration of S.P.M. has decreased considerably. The

improvement in environmental status is due to closer of foundry industries and other

small scale industries from TTZ. Along with this introduction of CNG and LPG operated

vehicles in public and private transport and development of green belt at TTZ has also

helped to improve the environmental status.

Year S.P.M.( Conc. in g/m3 )

SO2( Conc. in g/m3 )

NO2( Conc. in g/m3 )

2004 286.00 3.78 19.63

2005 275.00 3.48 16.07

2006 273.03 3.50 07.86

2007 263.41 3.42 07.45

2008 273.92 4.06 07.56

2009 253.10 3.41 06.61

2010 229.87 3.41 08.27


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The scenario of air quality in the ambience of Taj Mahal can further be improved by

taking following measures

1. There should be enough plantations in Taj Tripezium zone to prevent the flow of

dust laden wind.

2. In the radius of at least 5 Kms. from Taj Mahal, decongestion in traffic will be

needed.

3. In the residential and commercial areas which are located around Taj Mahal, the

people should be encouraged to use solar energy system instead of diesel

operated generator during the power cut / failure.

4. The water level in river Yamuna should also be maintained throughout the year.


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1. Introduction

Agra is rich in tangible cultural heritage having three World Heritage monuments

and several other nationally important monuments with incredible architecture. Taj

Mahal is the most famous World Heritage Monument of India. It was built by Mughal

Emperor Shah Jahan in 1643 on the bank of Yamuna. Besides Taj Mahal, Agra also

witness two more prominent World Heritage Monuments Agra Fort and Fatehpur Sikri

built by Mughal Emperor Akbar. Itmad-Ud-Daulahs tomb, Jama Masjid, Chini-Ka-

Rauza, Akbars tomb etc. are also some of the beautiful archaeological buildings.

In order to study state of conservation of above World Heritage Monuments and

to advise on various conservation problems, a team of UNESCO experts jointly with a

representative of Rhone-Poulenc, France visited Agra, India during 16-24 March, 1997.

After the visits to important monuments and on site discussions, the expert team of

UNESCO had a detailed deliberation with the representatives of Archaeological Survey

of India to explore the possibility of support from UNESCO/ Rhone-Poulenc in the field

of conservation of World Heritage and other monuments of Agra. UNESCO and Rhone-

Poulenc, France have agreed to provide financial as well as technical assistance in the

establishment of the laboratory. Accordingly, ASI was advised to work out requirements

for the equipments and other facilities. It was also recommended that ASI should

appoint one Physicist, one Geologist and one biologist to cater to the need of

multidisciplinary approach to the problems and to make the conservation much effective

and long lasting.


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1.1 Setting Up of Stone Conservation Laboratory

As per UNESCO-ASI-Rhone-Poulenc programme, the Stone Conservation

Laboratory has been set at Agra Fort, Agra and is functioning well for the cause of

conservation and preservation of World Heritage Monuments of Agra and other tangible

Cultural Heritage. Mr. Christian Manhart, UNSECO representative and ASI officials

jointly studied the requirements of instruments for the stone conservation laboratory and

as mutually agreed upon, following instruments have been procured through UNESCO

representative in India.

Stereo-microscope : To obtain three dimensionalzooming view of object

Polarizing microscope : To identify mineral composition of the rock

Isomet 1000 : To cut the rock specimen to prepare thin section

Ecomet-3 : To grind and polish the rock specimen

Slide warmer : To fix the rock specimen on the glass slide by hot

mounting process

Petrothin : Grinding & cutting of mounted specimen

The following equipment have also been procure to upgrade the Stone

Conservation Laboratory:

Compression Testing Machine :To evaluate compressive strength of stone block

Digital Camera & Software : As an aid to microscope for mineral identification

for microscope

Vacuum Impregnator :To consolidate weak rock sample before thin section

preparation

Mini Gloss Meter : To measure the gloss of stone surface


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2. Research Work

As the stone conservation laboratory is equipped with facility to prepare thin

section of stone samples and their microscopic studies. The stone samples of different

monuments and quarry have been received from the Laboratory of Director (Science),

ASI, Dehradun as well as from other establishments of ASI. During the year following

studies have been carried out in the Stone Conservation Laboratory:

Petrographic studies of stone samples of different monument.

Comprehensive Scientific investigations on Itmad-ud-daulah.

2.1 Petrographic Studies

Petrographic studies of inlayed stone samples of Taj Mahal have been carried

out to determine the texture, grain size, distribution pattern, binding material and mineral

composition of rock employed in inlay work. The transmitted light microscopy used in

identifying the constituent minerals reveals the complete inner matrix of the rock. The

porosity of the rock can also be assessed with the help of this study.

2.1.1. Samples

The stone samples were collected from Taj Mahal. One of the stone samples

was received from the office of the Director (Science), ASI, Dehradun. The thin sections

of stone samples were prepared in the Stone Conservation Laboratory, Agra.


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2.1.2. Preparation of thin sections

The thin sections of stone samples were prepared in the laboratory. The samples

were first cut in desirable shape & size by using Isomet-1000 stone cutter and then

ground and polished by different grit size carbimet papers with the help of Ecomet-3

grinder/polisher until the desired surface is obtained to mount on the glass slide. After

the mounting, the samples were again ground/polished to obtain a proper thin section.

2.1.3. Petrographic description

The thin sections of stone samples were subjected to microscopic studies to

obtain photomicrographs by using polarizing microscope, Nikon Make, Model E 600

POL. The mineral identification was carried out with the help of Geological Survey of

India, Lucknow. The description of photomicrographs is as follows.

2.1.3.1 Inlayed Stones of Taj Mahal

Yellow Stone

The rock is fine grained and essentially contains fine grained carbonates in the

matrix. Numerous fragments, pellets and planer sections of fossils are embedded in the

matrix. Lithic fragments mostly fine to medium grained quartz & muscovite also occur

embedded in the matrix.

Due to abundant fossil shell fragments within fine grained carbonate mud in the

matrix the rock may be Biomicrite.


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Gray Stone

The rock is predominantly consisting of fine grained carbonate mud alongwith

fine grained quartz & fine flakes of muscovite. Micro-fine branching cracks are common

in the rock and these fractures are filled by fine grained opaque. The carbonate phase

rapidly effervesces with application of acid. The rock in general is very fine grained with

neatly interlocked carbonate mud and exhibiting granular habit. The rock name is

Mudstone.

Stone conservation Lab, Agra

Figure 1 (a).:Photomicrograph under high magnification showing abundance of

fragments, pellets and sections of fossilsembedded in a fine grained carbonate mud.

Cross polars, 10x objective.

Photomicrograph under higher maginification

showing the exact nature of the sectional view offossil (centre). Note the coarse grained nature of

neomorphic spars (marked NMS). Cross polars,20x objective.

Stone conservation Lab, Agra


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Black Stone

Abundant fine grained xenomorphic quartz, plagioclase and carbonate constitute

the matrix of the rock. Granular fine hematite is randomly distributed and occurs asintergranular to quartz-carbonate assemblage. Fine flakes of mica are also present in

the rock. Fractures are common in the rock. The Rock is Calcareous Slate.

Stone conservation Lab, AgraStone conservation Lab, Agra

Stone conservation Lab A ra

Stone conservation Lab, Stone conservation Lab, Agra

Figure 2a: Photomicrograph under high magnification showing abundant fine grainedcarbonate mud with branching cracks filled with fine grained opaque which also occur as

dispersed in the matrix (fine black grains). Crosspolars, 10x objective.

Figure 2b: Photomicrograph under highermagnification showing the exact nature of the matrix constituent (abundant carbonate) with fracture filled opaque. Cross polars, 20x

objective.

Figure 3a: Photomicrograph under high

magnification showing abundant fine grained

quartz, carbonate, tiny grains of muscovite and granular opaque (mostly hematite) as matrix

constituent. Note the granular texture of the rock.Cross polars, 10x objective.

Figure 3b: Photomicrograph under higher magnification showing the exact nature of the

fine grained matrix constituents as detailed in above photograph. Note the fracture filled with

secondary, relatively coarser sized carbonate andquartz (marked Qz). Cross polars, 10x objective.


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2.1.3.2. Stone Sample of Sun Temple, Konark

Abundant medium to fine grained quartz with subsequent amount of stubby,

subhedral plagioclase occur as framework constituents of the rock. Thin mica plates

mostly muscovite also occur as ancillary. The quartz grains are mostly fractured and are

held together by ferruginous cement which is mainly hematite. Limonite is also present

as a result of oxidation of original cementing material. The rock is Ferruginous

sandstone.

Stone Conservation Lab, agra

Photomicrograph under high magnification showing abundant medium grained quartz (marked Qz), tiny grains of plagioclase

(marked Pl) and coarse, patchy hematite (marked Hm). Cross polars,

10x objective.


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3. Comprehensive Scientific Investigations on Itmad-Ud-Daulah

The Itmad-ud-daulah is also known as baby Taj due to architectural resemblance

with Taj Mahal although it was built well before about hundred years than Taj Mahal.

There areno complete scientific details on the monument. Therefore, the study focus on

the comprehensive scientific studies of materials used, weathering problems and their

remedial measures. In this part of the report the study has been carried out on following

points.

Detailed photo-documentation

Weathering Problems

Material used

Sample Collection

Microscopic Examination

3.1 Photo-documentation

In the first phase of the scientific investigation of Itmad-ud-daulah, the detailed

photo-documentation of the monument was carried out to know about material used and

basic problems of the monument.


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Stone Conservation Lab, Agra

Main Mausoleum of

Itmad-ud-daulah

One of the four gates of the

monument on the river side

Stone Conservation Lab, Agra


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The beautiful inlay work on marble with ornamental stones.

(a) (b)

(c)

(a), (b)& (c) : Inlayed stone works on the marble surface

Octagonal shaped dome on the first floor Unique ornamental work on thefloor of the dome


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Paintings on the lime plastered surfaces on the walls of main hall, side hall &

corner rooms along with stucco& painting work on the ceilings..

Painting on the corridor wall of main tomb Painting on stucco on the ceiling of corridor of

main tomb

Painting on the corridor wall of main tomb

Remains of painting on the upper

arch of river side gate


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Inlaying of marble & black stone on red sandstone surface on the Gates of the

monument.

Different patterns of design(Top &

right) of inlayed marble & black stone

on red sandstone surface


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3.2 Weathering Problems

Cracks: Cracks have seen on some decorated panels as well as on plane marble

blocks which may be due to mechanical stress and other physical factors.

Water marks due to seepage: Major factor of deterioration is water. The deposition of

insoluble salts as water marks and dissolution of matrix of ornamental stones are clearly

visible at several places.


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Disintegration of ornamental stone: Due to mechanical & environmental factors the

ornamental stones which are weaker in comparison to major building blocks get

deteriorated.

Due to formation of gap between inlayed stone and engraved surface, mortar

start loosing which ultimately results in detachment of ornamental stone.


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Fading of colour: It may be due to exposure to environment over a long period of time,

dissolution of matrix material & deposition of foreign material.

Crust deposition/ Patination: Crust/patina formation is very much predominant in

black ornamental stones. It may be due to deposition of salts, pollutants or may be due

to natural patina formation.

New

Old


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Leaching of iron and disintegration of marble due to iron dowel.

Flaking & Chipping of Red sandstone: Mechanical & environmental factors leads to

develop this problem in red sad stone. Flaking & chipping is weathering pattern of

sedimentary rocks.

Iron leaching

Disintegration


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Loss of Paintings: Inleft hand side picture, the painting loss may be due to bulging of

lime plaster which get restored later on. In right hand side painting loss may be due to

water seepage.

Partial loss No colour

3.3 Material Used

The basic structure of monument i.e. the main mausoleum and four gates has

been constructed with brick and lime mortar. The main mausoleum is veneered withwhite marble while gates with red sandstone. The main mausoleum is entirely covered

with inlay work. Mainly four types of inlay stones have been used.

Black stone

Yellow stone (Khatto)

Stone with embedded large yellow grains in reddish matrix (Ajubi)

Designer stone (Abri).

3.4 Sample Collection

Both the old and new samples have been collected with the help of In-charge of

the Monument. The photo-documentation of samples has been done which is shown

below.


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Samples of old Material

(a). Marble (b). Yellow Stone

(c). Ajubi (d). Abri

(e). Black Stone


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3.5 Stereomicroscopic Studies

Black Stone

The stereo-photomicrograph of new & old samples, (a) & (b). The whitish

material is clearly visible in the photomicrograph of old stone sample which may

be deposition of salts or some other foreign material. The photomicrograph (c) is

also of old stone sample with thick lime mortar layer on the right side of

photomicrograph.

(a) (b)

(c)


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Yellow Stone

The photomicrograph (a) of new yellow stone sample in 2xmagnification,

photomicrograph (b) of old yellow stone sample in same magnification. The aging

marks are clearly visible in old stone sample.

(a) (b)

The photomicrographs (c) & (d) are of new & old samples

respectively, and obtained by cutting the samples across the plane. Some

reddish tone in the stone matrix can be seen in old specimen.

(c) (d)


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Abri Stone

The stereo photomicrographs of Abri stone sample, New (a) & Old (b), has

been taken in 1xmagnification. The roughness of surface in old stone is clearly

visible which indicates the deterioration of stone matrix due to long exposure in

environment. The uplift of pale yellow grains can be seen in the

photomicrograph due to recession of grain boundaries & loss of cementing

material.

(a) (b)

Ajubi Stone

The stereo photomicrographs of Ajubi stone sample, New (a) & Old (b), in

1xmagnification. The roughness of surface in old stone is clearly visible which

indicates the deterioration of stone matrix due to long exposure in environment.

The uplift of larger grains can be seen in the photomicrograph as in case of Abri

stone.

(a) (b)


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3.6 TDS/Conductivity Measurement

The conductivity and total Dissolved Solids have been measured in the

ornamental stone samples with the help of Eutech conductivity meter, Model;

Con 510. De-ionised water has been used for the purpose. The results have

been shown below in the Table.

The conductivity and TDS value of new Yellow & Ajubi stone samples are higher

in comparison to old samples which may be due to less maturity of new stone

samples. There might be some other factors for this variation which is another

area of investigation.

3.7 Insoluble Inorganic matter

The results of conductivity & TDS measurements have been further

confirmed by determining insoluble inorganic matter of the ornamental stone

samples. The insoluble inorganic matter content has been found higher in new

yellow & ajubi stone samples in comparison to same old samples.

S.No. Description of stone

sample

Conductivity

(S)

TDS

(ppm)New Old New Old

1

2

3

4

BLACK

YELLOW

ABRI

AJUBI

49.7

81.8

73.0

76.9

48.4

56.4

78.8

56.5

24.8

40.9

36.5

38.4

28.2

28.4

39.4

28.3


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4. Present Status of Work

The research work on the stone samples of different quarry of Chunar,

received from the Laboratory of Director (Science), ASI, Dehradun is under

progress. The second phase of scientific investigation on Itmad-ud daulah will be

carried out. This will include instrumental analysis of material used in the

monument.

Other Activities of Air Pollution and Stone Conservation

laboratory

Training has been imparted to the newly appointed Assistant

Archaeological Chemists to make them acquaintance with the facilities available

in the laboratory and their application.

Training has also been imparted to the students of PGDA, Institute of

Archaeology every year to them aware of the work being carried out in the

laboratory.

Demonstration on research activities in the laboratory to the Officials of

ASI and other institutions.


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Air Pollution Laboratory, Agra

The Air Pollution Laboratory of A.S.I., Agra came into existence soon after

the commissioning of oil refinery at Mathura. A number of short term surveys by

NEERI & other organizations in the seventies to assess the likely impact of air

pollutants particularly SO2 on white marble of Taj Mahal. Apart from refinery,

other contributing sources of air pollution at that time were thermal power plant

near Agra Fort, foundries, tanneries, brick-kilns etc.

Stone Conservation Laboratory, Agra Fort

Agra has three World Heritage Monuments along with several centrally

protected archaeological sites. The requirement of a laboratory was felt to study

the state of conservation and preservation of such important monuments. The

ASI with the help of UNESCO & Rohn-Polenc, France took initiative to establish

a stone conservation laboratory in Agra. Consequently the Stone Conservation

Laboratory as an integral part of Air Pollution Laboratory has been inaugurated

on 28th November, 2006.

Dy. Superintending Archaeological ChemistArchaeological Survey of India

Documents

Annual Report of Air Pollution and Stone Conservation Laboratory