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ife in extreme

conditions

A time to live . . .

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Volunteer roadworkers

In Lesotho, a small land-locked country in southern Africa, the land is

subject to extensive erosion caused by severe drought followed byintensive rainfall, by heavy over-grazing, and fuel-wood cutting. To

combat erosion, increase agricultural production, improve the road

network and encourage the development of village woodlots, the Gov¬

ernment of Lesotho, assisted by the United Nations World Food Prog¬

ramme, organized a food-for-work project with voluntary labourers.

Women constituted 90 per cent of the work-force. Above, labourers

shovel earth while widening a track into a road.

55 Lesotho

Editorial June 198740th year

Man has always lived dangerously, ever since his most distantancestor, a hominid who probably lived on the African continent,took the first steps along the path of human evolution anddiscovered that a stone held in the hand could be used as a tool or a

weapon.

From the dawn of history onwards, human beings continuallycourted danger as the struggle for survival schooled them inresourcefulness and impelled them to the limits of endurance. Thisdetermination to perform seemingly impossible feats is a threadwhich runs through the pattern of human destiny and helps toexplain the extraordinary efforts made by human communities invarious parts of the world to adapt to extremely rigorousenvironmental conditions. From the primitive hunters whoconfronted their prey armed only with a stone axe, to the spacetravellers of the late twentieth century who must reach peakphysical and mental condition in order to spend long periods in astate ofweightlessness, human beings have always showncapacities for adaptation both to the natural environment and totheir self-imposed challenges. Man is by nature an inventive,forward-looking being whose relentless drive to master himselfand the world around him is so strong that today some fear that itmay even lead him along the road to destruction.

This issue of the Unesco Courier looks at the processes ofhumanadaptation and endurance as they are revealed in a number ofextreme and potentially dangerous situations. A medical doctordescribes his gruelling experiences during a solo expedition to theNorth Pole on skis, while another scientist presents some of thefindings of his extraordinary experiments in long-termconfinement underground, cut off from the rhythms of the solarday. Other articles examine the ways in which space voyagers dealwith weightlessness; the mechanisms of adjustment to highaltitudes; adaptation to conditions in deserts and tropical forests,to life on and under the sea, and to the wear and tear of everydayexistence in the modern world. Finally we evoke the phenomenalexploits of a Norwegian long-distance runner who a century and ahalf ago ran across Europe and parts of Asia and Africa at a rate ofaround 150 km a day.

Survival

Human adaptation to extreme conditionsby Felix Z. Meerson

8

It's tough at the topLife at high altitudeby Gerardo Antesena, Mario Paz-Zamoraand Enrique Vargas

12

Travelling lightCoping with weightlessness in spaceby Oleg G. Gazenko

14

The time of our lives

Subterranean experiments on the rhythmsimposed by the solar dayby Michel Siffre

16

The desert as a way of lifeby Hamidou A. Sidikou

20

Hunter-gatherers of the tropical forestby Laurentiu Palade

23

The sea within us

by Dan Behrman

27

Stress in the modern world

by Lennart Levi

30

Solo to the Pole

Interview with Jean-Louis Etienne

33

Marathon Man

by Bredo Berntsen

A time to live...

LESOTHO: Volunteer roadworkers

Editor-in-chief: Edouard Glissant

Cover: Caravan in the Sahara (Mauritania).Photo ©MaximilienBruggmann, Yverdon,Switzerland

The CourierA window open on the world

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SinhalaISSN 0041-5278

N°6-1987-CPD-87-l-'i46 A

SURVIVAL

Human adaptationto extreme conditions

by FelixZ. Meerson

ADAPTATION, in human beingsand in animals, is a processwhereby the organism gradually

acquires resistance to certain factors in itsenvironment and consequently thecapacity to live in conditions previouslyincompatible with life, and to solve pre¬viously unsolved problems.

"To live in conditions previouslyincompatible with life" can mean com¬plete adaptation, allowing a wide rangeof physical and intellectual activity as wellas the perpetuation of the species in con¬ditions of polar cold, desert heat or short¬age of oxygen at high altitudes, just as itcan mean a far from complete adaptationwhich permits only survival for a more orless extended period.

Likewise, "to solve previouslyunsolved problems" includes resolutionof elementary problems, such as how toavoid attacks by predators by standingstock still a passive defence reflex orof more complex ones, such as travellingin space or controlling the life processesof the organism.

All these adaptive mechanisms haveone feature in common: although in theinitial phase of adaptation to any newfactor the organism is close to the limits ofits capacities, the manner in which itsolves the problem is far from perfect.However, if the person or animal con¬cerned survives, and the causal agent ofadaptation continues to be active, thepossibilities open to the organismincrease and the extreme or urgent stageis replaced by one of effective, stableadaptation.

This transformation is the crucial

moment in the whole process, and it oftenhas' remarkable consequences, as in thecase of the experiments carried out by aPeruvian scientist who "lifted" in a pres¬surized chamber a group of people, someof whom were already adapted to highaltitudes while others were not. When the

pressure was equivalent to that at an alti¬tude of 7,000 metres the novices lost con¬

sciousness, while the others continued

playing chess.Similarly, a healthy but untrained per¬

son can run a few hundred metres at the

most without stopping to rest, whereas atrained runner can cover more than 40

kilometres. The cold weather which hit

Western Europe in the winter of 1986-87had catastrophic effects in some countriesand caused a number of deaths. Duringthe same period in Verkhoyansk, a townin eastern Siberia and one of the coldest

places on Earth, eight- to nine-year-old

children continued going to school intemperatures of -57 °C and herds ofthoroughbred horses grazed as usual,watched over by their herdsmen.

In the field of intellectual activity,where adaptive reactions are qual¬itatively more complex, the transitionfrom the stage of extreme tension to thatof stable adaptation is manifested in an

In 1984 a group of walkers crossed a partof the Kara-Kum desert in the Turkmen

S.S.R. during a Soviet experiment on life indesert regions. The walkers were notallowed to drink water during thisendurance test, which was closelymonitored by doctors. Right, a doctorexamines two walkers during a restperiod.

In 1979, a seven-man Soviet expeditionreached the North Pole after a 1,500 kmtrek on skis across drifting ice. The expedi¬tion, which took two and a half months,made a notable contribution to knowledgeabout life in Arctic regions (see the UnescoCourier, January 1980). A ceremony (be¬low) was organized at the Pole to celebratethe achievement.

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equally striking manner. This transfor¬mation of an unadapted organism into anadapted one is well known, and has beendescribed in detail.

Two interrelated series of phenomenadevelop in the organism faced with a newsituation. In the first series there is a rapiddevelopment in the function of the sys¬tem most directly concerned in the adap¬tation process, for example the organs ofmovement, blood circulation or respira¬tion when a physical effort is involved, orspecialized parts of the brain during train¬ing and acquisition of new skills. The cellsreact by increasing the synthesis ofnucleic acids and proteins, and a selectivedevelopment of the structures limitingthe function occurs. Thus, during adapta¬tion to altitude or physical effort, the cor¬onary arteries expand and there is a twoto threefold increase in the number of

"power stations" (mitochondria) in theskeletal muscles. As a result, a series of

changes takes place in the cells of thedominant system, that on which adapta¬tion depends, which increases the phys¬iological capacity of the system and formsthe material basis for the transition from

an extreme stage to genuine adapta¬tion.

The second series of phenomena is thewell-known stress reaction discovered bythe Canadian biologist Hans Selye, whichhe called "general adaptation syn¬drome". It is now known that the stress

reaction manifested by the secretion ofadrenal hormones into the blood not onlymobilizes the organism's energy andstructural resources, but also ensures

their transfer from inactive systems to thedominant system. In other words, thereaction allows the vitally importantproblem created by the environment to

be solved. When adaptation has beenachieved and the individual has become

accustomed to the cold, or learned to

solve mathematical problems or to playthe piano, the stress reaction disappears.Adaptation to other physical or chemicalfactors in the environment takes place inthe same way (e.g., gradual habituationto increasing doses of poison).

Afterwards the organism can no longerbe damaged by the external factor towhich it has become adapted. It isremarkable that the multiple reactionsset off by the process of adaptation to oneenvironmental factor frequently containcomponents which heighten resistance toother factors. Thus adaptation to aninsufficiency of oxygen strengthens theorganism's resistance to physical effort,hallucinogens, epileptogens, factors pro¬ducing high blood pressure, stressdamage to the heart, ischaemia (interrup¬tion of the blood supply to an organ ortissue), and even to ionizing radiation.

This opens up vast possibilities for theutilization of adaptation in the preven¬tion and treatment of diseases. Nowa¬

days, when extensive use and in somecases abuse of medicines creates a real

possibility of dependence on them, itwould be useful to have doctors pre¬scribe, not only medicines, but adapta¬tion to a complex of individually selectedfactors.

It is now known that external stress can

provoke or speed up the development ofgastric and duodenal ulcers, high bloodpressure, arteriosclerosis, ischaemicheart ailments, diabetes, mental disor¬

ders, skin troubles and as has been

shown recently tumours.

Below, Soviet divers study the diffusion oflight underwater, during research in theIndian Ocean conducted by the MarineBiology Institute of the USSR Academy ofSciences Centre for the Far East.

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However, the role of stress in certain

pathological conditions is now so wellknown that it may obscure the importantfact that most human beings and animals,placed in extreme conditions from whichthere is no escape, do not die but acquiresome degree of resistance which allowsthem to survive until better times. Such

situations prolonged periods of hunger,cold, natural catastrophes, interspecificand intraspecific conflicts still occurwidely among animals in their naturalhabitat.

More complex stress situations occurjust as frequently in human society. Dur¬ing a relatively short historical era manhas survived periods of slavery, serfdomand world war in such a way as to provethe efficiency of his powers of adaptation .Of course, the price of this adaptation hasbeen unjustifiably high, but these indis¬putable facts inevitably lead to the con¬clusion that the human organism must be

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endowed with efficient specialized mech¬anisms that limit the reaction to stress and

prevent stress damage.Research carried out in the last decade

has confirmed the existence of these

stress-inhibiting mechanisms. It has beenshown that under pressure from extremetensions, the stress reaction is accom¬

panied by intensified activity of the cen¬tral stress-inhibiting systems. One exam¬ple is the increased production in thebrain of morphine-like opiate peptidesand other substances which limit the

stress reaction. These substances

accumulate in the brain and neutralize

the stress-inducing excitation of thenerve-centres.

The activity Of the stress inhibitors alsointensifies in the other organs, where sub¬stances accumulate that limit the action

of stress hormones on the cells and pre¬vent stress damage. The dual activity ofcentral and local stress inhibitors protects

the organism from gastric ulcers, heartdamage , impairment of immune systems ,arrhythmia, and injury caused by chemi¬cal factors.

These facts generally correspond towhat can be observed in everyday life.People who have experienced terribleordeals acquire a certain resistance to thewear and tear of life. Moreover, the pos¬sibility can now be envisaged of employ¬ing substances produced by stress-inhibiting centres, equivalent substancesproduced by synthesis, and the chemicalactivators of such inhibiting systems, assubstitutes for the natural mechanisms of

adaptation, in order to protect the organ¬ism from stress and other forms of

damage. This theory, now largely con¬firmed by experiment, opens up highlypromising prospects for the preventionand treatment of non-infectious diseases.

The little town of Verkhoyansk in easternSiberia (Yakut Autonomous S.S.R.) is oneof the coldest places on Earth. Commonwinter temperatures of -60°C do not dis¬turb the tenor of life. A hardy local breed ofhorses Is raised on a Verkhoyansk farm,above.

FELIX ZALMANOVICH MEERSON, Sovietspecialist in pathology, is president of the Spe¬cialized Commission on the Pathophysiology ofAdaptation Processes attached to the ScientificCouncil of the USSR Academy of Medicine. AWorld Health Organization (WHO) expert and amember of the editorial boards of several inter¬

national science journals, he is the author of 14monographs, some of which have also beenpublished in the USA, the Fed. Rep. of Germanyand in Japan, and is co-editor-in-chief with Aca¬demician Oleg G. Gazenko ofThe Physiology ofAdaptation Processes (1986). He was awardedthe USSR State Prize in 1978.

Suspension bridge over the riverApurimac in the eastern cordillera (Peru)was made of plaited grass using tech¬niques known to the Incas. It is rebuiltevery year.

IT'S

by Gerardo Antesena,Mario Paz-Zamora

and Enrique Vargas

T|HE overwhelming majority of the

world's population live betweensea level and an altitude of 3,000

metres. Only some 15 million persons livein permanent settlements between thatlevel and 4,800 metres, mainly on thehigh plateaux of the Andes in SouthAmerica, and of Tibet in Central Asia.

Altitude inevitably imposes constraintson people who live in these regions. In thefirst century AD, Pan Kou, a Chinesehistorian, described in these terms the

Karakoram mountain range in CentralAsia: "It is necessary to cross two moun¬tains, one large and one small, whichmake the head ache. The earth lies naked

there, on the scorching slopes, and thehuman body loses its colour because ofthe heat; the torrid sun causes headachesand nausea, and it has the same effect onanimals ..."

Father José de Acosta, a Jesuit mis¬sionary to the New World, describesacute mountain sickness in his treatise

Historia natural y moral de las Indias(1590; Natural and Moral History of theIndies, 1604), and relates it to the fact thatat such altitudes "the air is so subtle and

so refined that it is unsuited to human

respiration, which needs air that isthicker and more temperate ..."

What exactly is meant by the term alti¬tude? Altitude in the sense of environ¬

ment consists of a number of physical fac¬tors, principally the lowering ofbarometric pressure1 and therefore of thepartial pressures2 of respiratory gases , thewide range of variation in day and nighttemperatures, increased solar radiation

and a greater incidence of high-energyheavy particles in the atmosphere.

The lowering of barometric pressure isby far the most important factor as far asman is concerned, arid it is an unavoida¬

ble constraint to which technology hasfound no practical long-term solution.Consequently, the values of the partial

1. Atmospheric pressure as indicated by a barometer,usually of mercury, and expressed in several differentsystems of units, such as pounds per square inch, ormillimetres of mercury.2. The pressure that a gas, in a mixture of gases, wouldexert if it alone occupied the whole volume occupied bythe mixture.

8

TOUGH AT THE TOP

Life at high altitude

pressure of respiratory gases, especiallythat of oxygen in the arterial blood, areusually taken as the basis for determiningthe physiological limits of altitude.

"Physiological" altitude therefore doesnot correspond to physical altitude. Onthe one hand, the fall in atmosphericpressure is not directly proportional toheight above sea level; on the other, theoxygen content of the blood is not a sim¬ple function of the partial pressure of oxy¬gen in the air. Three levels can be dis¬tinguished, according to the value of thepartial pressure of oxygen in arterialblood:

- above 70 millimetres of mercury,changes in the partial pressure of oxygen

(i.e. in altitude) have little effect on theamount of oxygen contained in the blood .(The normal arterial blood pressure atsea level is 90 millimetres of mercury.);- between 70 and 40 millimetres of merc¬

ury, the effect of the fall in the partialpressure of oxygen becomes morenoticeable;

- below 40 millimetres of mercury, theoxygen content of the blood falls consid¬erably and more or less constantly withsmall changes in the partial pressure ofoxygen.

Altitudes of less than 3,300 metres cor¬

respond to the first level; there are nosignificant effects on the oxygen trans¬porting function of the blood.

The Ourou Indians live in floating settle¬ments on Lake Titicaca, one of the world's

biggest mountain lakes (8,340 km', alti¬tude 3,812 m), on the border of Peru andBolivia. Above, a group ofOurou Indians intheir boats made of bundled reeds.

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Harvest scene In the Dolpo Valley (Nepal),4,000 m up in the Himalayas. Barley is theonly cereal grown in the valley.

It is impossible for man to live perma¬nently at the third level above 5,500metres.

Altitude, in the physiological sense ofthe term, thus corresponds to a level ofbetween 3,300 and 5,500 metres (a baro¬metric pressure of between 500 and 370millimetres of mercury).

The main problem for the humanorganism in such an environment con¬sequently lies in transferring oxygen fromthe atmosphere to the cells.

Like the higher animals, man has twoactive transfer mechanisms: the respira¬tory system, and the circulatory systemwhich distributes to the various tissues

the oxygen bonded to the haemoglobin inthe blood. At an altitude of over 3,500

metres the partial pressure of oxygen inthe air is insufficient to saturate the

haemoglobin. Respiration and circula¬tion rates are therefore the most

affected.

People living at high altitudes havemore red corpuscles and morehaemoglobin circulating in their blood,and this makes up for the fall in the partialpressure of oxygen. This increase in redcorpuscles at high altitudes allows thecardiac output to return to, or sustain, itssea level value. These two responses,greater cardiac output and an increase- inthe number of red corpuscles, have thesame purpose: to convey to the tissues the

oxygen they need, despite its rarefactionin the atmosphere. The first is an immedi¬ate functional response; the second ismore adaptive and takes over from thefirst.

Reduced barometric pressure is not theonly constraint due to altitude; cold isusually an associated factor. Some phys¬iological responses to cold, such asdecreased circulation to the skin, are

also among the responses to altitudehypoxia.3

Man is thus not naturally suited to lifeat high altitudes; all the regulatory andcontrol mechanisms of the human organ¬ism work in accordance with sea level

conditions. However, in temperate andtropical regions people live at heightswhere the barometric pressure is close tohalf that of sea level, and most of the

body's functions have adjusted accord¬ingly.

People have travelled through andlived in high altitude regions since ancienttimes. They have served as places ofrefuge or as extensions of land used forstock-rearing, for example. The inhabi¬tants have adapted physiologically tothese exceptional living conditions, butthey depend for subsistence on the poorpasture land which feeds the animals they

3. Deficiency in the amount of oxygen delivered to thebody tissues.

raise, and they are always at the mercy ofa severe winter which could decimate

their beasts. They also rely on the watersupply from glaciers to irrigate theirfields.

The people who live in the highplateaux of South America or CentralAsia lead an active life as farmers and

herdsmen. Their extensive empiricalknowledge of the soil and climatic condi¬tions has enabled them to create a highlyefficient system of terraced irrigation andcultivation. They follow a sowing time¬table which ensures that crops can be har¬vested in the minimum of time, and theyknow how to cross-breed animals to

increase their resistance and how to store

food as a precaution against irregular har¬vests. The growing of cereals and the rais¬ing of animals are closely interdepen¬dent, for intensive agriculture is onlypossible if manure is available.

The Andean peoples grow potatoes,maize (corn), fava beans and quinoa (aplant of the Chenopodium family) andraise llamas and vicunas. They use thewool and meat of another camelid, thealpaca, as well as its skin and its fat, whichis thought to have therapeutic powers.The breeding of these animals and ofoxen and sheep, which were introducedin the sixteenth century, is their main live¬lihood: a herd of 200 animals is needed to

maintain a family of six.

10

Several centuries of exploitation ofmineral resources have led some peoplesto settle at altitudes of around 4,800

metres at the Chorolque mine inBolivia, for example. In Central Asia,the farmers who live in the southernmost

and easternmost valleys of Tibet growbarley, peas and, more recently, potatoeson irrigated land. They also raise oxenand sheep.

Nomadic tent-dwelling herdsmen inthese regions live entirely by stock-rear¬ing. In the main they breed animals suchas yaks, sheep, goats and horses, whichare well suited to the conditions. The yakprovides them with milk, from which theymake butter and cheese, as well as meat,skins and hair; it is also used as a beast ofburden. These nomads control the

greater part of the transport and trade insalt, bartered for grain from the lower-lying valleys.

In order to obtain food and survive at

high altitudes, the inhabitants of theAndean and the Central Asian mountain

ranges have developed production sys

tems designed to subjugate nature,reduce risk, and make the most of avail¬

able resources (in the case of the Andes,by making the maximum use of the ecolo¬gical zones at different altitudes). Theiraim is to take from the environment all

that is necessary to meet their needs, atthe same time eliminating or reducing cli¬matic risks. This is a basic feature of the

relationship between high mountainsocieties and their environment, and it is

to be seen not only in agriculture andstock-rearing, but in all the otheractivities of their life the procurementof food, shelter and a dwelling-place.

The very wide range of individual reac¬tions suggests that altitude may have hada selection pressure on peoples living per¬manently in high-altitude regions, andthat throughout the generations suchselection may have favoured people whowere better suited to develop favourableresponses and, even more, to reducethose responses likely to proveunfavourable.

GERARDO ANTESENA, MARIO PAZ-ZAMORA and ENRIQUE VARGAS, of Bolivia,are directors of research on the high-altitudephysiologyandpathology ofman in the Andes, atthe Bolivian Institute of High-Altitude Biology(IBBA) of the Major San Andres University, LaPaz. These studies are also carried out at the

high-altitude stations of Potosí (4,200 m),Chorolque (4,800 m) and in the lowlands atSanta Cruz (400 m).

Entrance shaft of the "Siglo XX" tin mine,part of Bolivia's most important miningcomplex. The Bolivian writer SergioAlmaraz Paz has written of this miningregion, over 4,000 m up In the BolivianHighlands or Altiplano, "There is nocolour; nature is clad in grey. Contaminat¬ing the belly of the earth, the ore has trans¬formed it into a desert. "

11

TRAVEUmG__LIGHT

Coping with weightlessness in spaceby Oleg G. Gazenko

IT is just over a quarter of a centurysince man first ventured into space.An assessment of the achievements

of astronautics so far indicates that man

now,has a firm foothold in the realm of

space travel and that the human factorwill be decisive in the conquest of outerspace.

Today systematic study is being madeof all aspects of the Universe, with pri¬ority being given to the exploration of theEarth from space and to the use of spacetechnology to solve many of the problemsof our planet.

Every space flight makes an importantcontribution to this enterprise, furtheringthe study of the Earth's natural resourcesand of the world ocean, the application ofnew technologies and the development ofnew products (especially pharmaceuticalcompounds and biological substanceswhich are difficult or impossible to ob¬tain on Earth because of the effects of

gravity) and the monitoring of theenvironment.

Cosmonauts are remaining in space for.longer and longer periods and arerequired to perform increasingly numer¬ous and complex tasks, including man¬oeuvres outside their spacecraft, which

call for continual progress in medicalresearch to ensure that space travellersremain healthy and capable of working atfull capacity.

Already, the findings of such researchhave opened up new perspectives on theworkings of the human organism, leadingnotably to a greater understanding of thegeneral laws governing adaptation to theenvironment, and above all adaptation tosuch an unusual condition as weightless¬ness, which man does not experience onEarth.

Throughout its long evolution thehuman body has never had occasion tomake use of mechanisms capable of com¬pensating for absence of gravity. On thecontrary, the whole evolutionary processhas been to fight against the force of grav¬ity, in order to survive in the continualheaviness imposed by the Earth's gravita¬tional pull. Gravity influenced thedevelopment of the structures and func¬tions of the cardio-vascular system, themotor system and the central nervoussystem.

The degree of adjustment that we haveattained, which makes us human, is thus a

logical development, and the individualin the course of his life is capable of refin¬ing and improving that adaptation, just ashe can lose it, at least in part, usuallythrough ageing or illness. However it hasbeen observed that this can also happento young, healthy subjects when theytravel in space and experience weight¬lessness.

Before the first manned space flight,some scientists claimed that man would

be incapable of working in a state ofweightlessness. They even went so far asto declare that a normal human beingwould be psychologically unable to copewith the state of weightlessness and thecosmic void. The space flight of YuryGagarin resoundingly disproved thesepessimistic predictions and, by showing

On board the U.S. Space Shuttle Columbia, gjlThe astronaut at left tries out a sleeping @|bag, while another, right, equipped with g-suction cups on the soles of his shoes, ^floats with two cameras in a state of |weightlessness. è

that human beings can indeed journeythrough space, flung open the gateway tothe stars.

How does weightlessness influence thehuman organism? What changes does itproduce, and what shocks can it causeagainst which preventive measuresshould be taken?

Weightlessness first of all produces asensation of disequilibrium and of float¬ing, due to a disruption in the normalfunctioning of sense organs such as thevestibular apparatus of the inner ear,sight, touch and muscle awareness. Thecosmonaut has the impression of flyingupside down or falling. Sometimes this isaccompanied by disagreeable and veryuncomfortable sensations of giddiness,weakness or nausea. The form and dura¬

tion of these symptoms vary greatly fromone individual to another. On more than

200 space flights, two-thirds of the sub¬jects experienced them to some extent,lasting for periods ranging from a fewhours to several days. Subsequently thesymptoms wear off, only to reappear, as arule, for the first few hours or days afterreturning to the Earth's gravitationalfield.

The absence of gravity subjects the car-

12

dio-vascular system to a redistribution ofthe total amount of blood in the body:instead of accumulating in the lower partof the body, the blood tends to rise intothe thoracic and cephalic regions. Thismodifies the regulation of the heart andthe metabolism of the cardiac muscle,which gradually weakens, and also causesa loss of tone and elasticity in the veins ofthe legs. If this state is prolonged, theabsence of blood pressure causes a deteri¬oration in the reactions of the cardio-vas-

cular system to physical effort or to move¬ment, and it starts to "run down".

As the influence of weightlessness con¬tinues, other forms of reaction emerge,owing to the lack of demands made on thebones and muscles. Indeed, without grav¬ity, no effort is required to move aroundinside the space station or to shift objectsfrom one place to another. A gradualfunctional atrophy of the muscles occurs,starting with those which are used to com¬bat gravity, hold certain positions andcompensate for the Earth's gravitationalpull during movement. This leads to apartial wastage of the muscle mass,especially the muscles of the legs andback.

Decalcification of bone tissue occurs

through loss of calcium salts and phos¬phorus, but this has never reached alarm¬ing levels, even on the longest spaceflights. However, if effective measuresare not taken, decalcification could

become a serious obstacle to longer man¬ned space flights.

These phenomena and other phys¬iological reactions to weightlessness areprimarily functional and do not constitutea threat to cosmonauts' health.

Furthermore, it is abundantly clearthat human adaptation to the state ofweightlessness signifies, to some extent, aloss of adaptation to the conditions of lifeon Earth. A rather singular situation thenarises: the more complete the adaptationto weightlessness, the more difficult is theprocess of .readaptation after re-entry.All cosmonauts who have spent time inorbit are familiar with this experience.How far this process can be a threat totheir health is difficult to determine.

Adequate scientific evidence is lacking toenable a valid judgement to be made,since for all space flights lasting morethan three weeks various methods have

been used to protect the cosmonautsfrom the negative influence of weight¬lessness.

In view of the increasing duration ofspace flights, doctors have been obligedto devise ways and means of counteract¬ing too great an adaptation to weightless¬ness, in order to ensure that the mecha¬

nisms indispensable to life governed bythe Earth's gravitational field continue tofunction effectively. It has been neces¬sary to prevent the body's systems from"forgetting" their terrestrial vocation andto "remind" them of their, role onEarth.

These measures include, first and fore¬

most, physical training on bicycles andmoving running-tracks to tone up themuscles. During long space flights, cos¬monauts walk approximately 5 kilo¬metres a day, and cycle for some 10 kilo¬metres. The amount of exercise dependson the day in the training cycle, the dura¬tion of the flight and the individualcharacteristics of the body. Additionalexercises using extensors and otherapparatus can also be carried out ifnecessary.

To prevent circulatory disorders, thecosmonauts have to exercise while nega¬tive pressure is applied to the lower partof the body. They put on a special gar

ment like a pair of baggy trousers made ofstretch fabric, in which a vacuum pumpestablishes a permanent degree of nega¬tive pressure. As a result the blood flowsinto the lower parts of the body, wherethe blood pressure rises to the same levelas on Earth. This stimulates circulation in

the legs and prevents reduction of theability to stand upright which tends toaffect cosmonauts returning to Earth.

During the last few days of the flightthe cosmonauts take in salt-water solu¬

tions, causing fluid retention and anincrease in the volume of blood. This also

makes it easier for them to maintain an

upright stance on their return. Anothervery important preventive measure is toadd an extra ration of vitamins and trace

elements to the diet.

In the future, recourse will very proba¬bly be had to artificial gravity, but this is acomplex problem which calls for verycareful study, through experiments bothon Earth and in space.

Above, two cosmonauts take a shower on

board the orbiting Soviet space stationSalyut 7.

Left, a cosmonaut (foreground) works outon an ergometric bicycle in the Sovietspace station Salyut 7. This type of exer¬cise is vital to enable the body to readaptto Earth's gravity after a time spent inspace.

Much is now known about the body'sreactions to weightlessness, and howthese reactions come about is largelyunderstood. The general impression isthat man is capable of adapting satisfac¬torily to a prolonged state of weightless¬ness, then of re-adapting to gravity andsmoothly returning to a normal and use¬ful life on Earth.

However, since human health and

safety are at stake, it is important toassess each new step in space explorationwith meticulous accuracy, and to pay theclosest possible attention to the smallestdetails in the growing store of experience.Nothing must be overlooked, from theremote consequences of space flightsalready undertaken to the difficulties andcomplications likely to be faced on futureflights. Science, especially biological andmedical research in space, has a long wayto go in order to perfect knowledge ofMan and the Universe and penetrate thecomplexities of the interaction betweenthe two, thereby helping to achieve a har¬monious relationship.

OLEG GEORGIEVICH GAZENKO, Soviet sci¬entist, is director of the Institute of Medical and

Biological Problems and president of the SovietI. P. Pavlov Society. He is an active member ofthe Academy of Sciences of the USSR and of the"Man in Space Studies" Committee of the Inter¬national Academy ofAstronautics. The author ofover 200 scientific studies, he was Soviet editor

of a Soviet/U.S. publication, Foundations ofSpace Biology and Medicine (7975, in Russianand English). He was a recipient of the USSRState Prize in 1978 and the Guggenheim Inter¬national Astronautics Award in 1975.

13

Subterranean experiments on the rhythms imposed by the solar day

PHYSIOLOGISTS since the time of

Hippocrates and probably even ear¬lier have demonstrated the impor¬

tant ways in which man is conditioned byenvironmental rhythms, especially thetwenty-four-hour alternation of night andday.

In man, as in other animals and plants,rhythmic variations in a whole range ofphysiological functions alternation be¬tween sleep and waking activity, formationof glycogen (animal starch) in the liver,temperature change, metabolism, forexample occur regularly every twenty-four hours.

Known as "circadian rhythms" (from theLatin circa: "about", and dies: "day"),these more or less independent or inter¬dependent rhythmic variations, operatingthroughout the day/night cycle, constitutethe mechanism that is termed man's "bio¬

logical clock".These circadian rhythms are of consid¬

erable importance. If they are interruptedor too rapidly or abruptly thrown out of

phase, serious physical and psychologicaltroubles can result. It is common knowl¬

edge that total deprivation of sleep over aperiod of several days is certain to entailmarked deterioration in mental and physi¬cal performance. After an east/west or west/east flight of only a few hours it may take apassenger's rectal temperature rhythm aslong as fifteen days to adapt to the appropri¬ate rhythm of the new local time.

It is generally held that, under normalconditions on earth, environmental factors,and especially the alternation of night andday, act as phase-setters or synchronizerswhich maintain the coincidence between

human circadian rhythms and the localtwenty-four-hour time scale. What,however, would happen to our biologicalrhythms, to the bundle of nerve cells whoseprecise location in the brain is now beingestablished and which register the periodicsignals of the environment, were those sig¬nals to be suppressed?

Botanists and biologists have known for along time that cycles of about twenty-four

hours continue in many plants and animalseven when they are kept either in totalobscurity or in continuous light. However,concentrated research on the adaptation ofthe human organism to an aperiodicenvironment, that is to say to an environ¬ment in which the normal phase setters orsynchronizers are lacking, only began inearnest in 1962.

The three main situations in which these

conditions apply are those in which peoplefind themselves living for long periods inspace, underground or under water. Wouldthe human organism continue to show evi¬dence of regulation by circadian rhythmsonce deprived of the environmental syn¬chronizers it had known throughout the mil¬lions of years of human evolution? Arethere, in fact, other rhythms specific to thehuman organism?

This was the crux of my long-term experi¬ments, deep iq an underground cave, whichhave added to our knowledge of how manadapts to a timeless, aperiodic environ¬ment. These experiments have shown how

14

Left, Michel Siffre's subterranean camp inMidnight Cave (Texas). The ergometricbicycle enabled him to study heart fatiguepatterns during his confinement.

complex that adaptation is and how much itvaries from individual to individual, andhave afforded a better understanding of themechanism of human circadian rhythms.

Without synchronizers, without time"landmarks", whether natural (alternationof day and night) or artificial (clocks orwatches), each individual's internalrhythms appear to be, but in fact are not,synchronized with the rhythms of localtimes on Earth.

The most important findings concern twodistinct fields of interest the evolution of

the sleeping/waking cycle and of other phys¬iological functions (such as temperatureand cardiac rhythms), and the internalstructure of sleep itself, which lies withinthe field of neurophysiology.

With regard to the sleeping/waking cycle,all the long-term (two to six months) experi¬ments I carried out between 1962 and 1972

seem to point in the direction of a lengthen¬ing of the cycle, that is to say, a lengtheningof the interval between two waking periodsand two sleeping periods. This has beenconfirmed by the experiments carried outby all the other research teams (mainly Ger¬man, British and American) who haveworked on this problem, even though thesewere of shorter duration (about onemonth).

Although those who have written on thissubject seem to be agreed on a statisticalaverage for the sleeping/waking cycle ofaround twenty-five hours, this has little sig¬nificance with regard to the individual. Mylong-term experiments have brought outclearly the multi-faceted nature of a particu¬lar rhythm and its unreproducibility over agiven period of time. This has been demon¬strated in spectacular fashion by the factthat whereas for some individuals the sleep¬ing/waking cycle changes within a few daysfrom twenty-four to forty-eight hours(thirty-four to thirty-six hours of continuouswaking activity and fourteen to twelvehours of sleep), for others this may not hap¬pen for several months. A comparisonbetween my 1962 experiment (when I wasisolated on the underground glacier atScarasson in France from 16 July to 17 Sep¬tember) and my second experiment in 1972(205 days alone in Midnight Cave, Texas)shows clearly the unreproducibility of thesleeping/waking cycle.

A significant outcome of this spon¬taneous change from a twenty-four-hour toa forty-eight-hour cycle is that for just athird more sleep than is normal underordinary conditions of life it is possible to

Before descending into Midnight Cave,where he remained alone, cut off fromthe solar day, for 205 days in 1972, theFrench speleologist Michel Siffre mea¬sures his respiration rate in the surfacelaboratory.

double the period of waking activity, a veryconsiderable potential increase in creativeactivity, entirely naturally and without hav¬ing recourse to any form of drug, for aperiod of several weeks.

Desynchronization of the circadianrhythm of sleep and waking activity is paral¬leled in most of the other physiologicalrhythms examined, such as the cardiacrhythm, the rhythm of the rectal tempera¬ture, of potassium and of the hydroxycor-ticosteroid hormones.

I believe that this desynchronization is anadaptive response by the organism to theaperiodicity of the environment. Thisbrings me to the second group of importantfindings concerning the structure of sleep ina timeless situation. We were the first to

undertake such studies which were carried

out in 1966. Under a forty-eight-hour sleep¬ing/waking cycle the human organism the¬oretically builds up a sleep deficiency ordebt. The question then arises as to which ofthe major stages of sleep (see below) isreduced to compensate for the abnormal(thirty-six-hour) period of waking activity.

Progress in this field of research was onlymade possible by underground, atemporalexperiments. Previous experiments onsleep had been carried out within the con¬text of local time and of a circadian (twenty-four-hour) sleeping/waking cycle. Con¬sequently, the natural variations in the vari¬ous stages of which sleep consists could onlybe very limited. The relative proportions ofwhat is known as REM (Rapid Eye Move¬ment) sleep and the four other stages ofsleep could only vary minimally around themean average, which itself varied accordingto the individual concerned and the time of

the year.However, the spontaneous changes in

periodicity of the sleeping/waking cycle(cycles of 12, 24, 26, 28, 36, 48, 60 and even72 hours) occurring within the frameworkof my "out of time", aperiodic experimentsrevealed the natural evolution of the time

devoted to each stage of sleep, especially toREM sleep and to what is known as Stage 4sleep (deep sleep), as a function of totalsleep and in relation to the biological cyclesand the waking period.

In short, the neurophysiological adapta¬tion of the human organism in an "out oftime" setting is marked by profound modi¬fications in the internal structure of sleep,which vary from individual to individual,and which can be summarized as follows:

Whatever the duration of the sleeping/waking cycle, the proportion of REM sleepcan be accurately forecast since there is aprecise linear correlation between REMsleep and total sleep, of which it is a func¬tion. This phenomenon was observed forthe first time in man during my experimentsunderground.

When the period of continuous wakingactivity doubles (rising from 16 to 34 or 36hours), total sleeping time does not double.However, REM sleep increases in a ratio ofabout one to ten to the length of wakingactivity.

The change from a circadian to a forty-eight-hour sleeping/waking rhythm doesnot affect the period (some 90 minutes) ofREM sleep, which remains stable.

To conclude this brief survey of the timefactor in human adaptation, it should berecognized that it is an imperative necessityfor ever more penetrating studies to be car¬ried out on the desynchronization of circa¬dian rhythms in order to increase man's vig¬ilance and operational capacities. The studyof the desynchronization of the biologicalclock is all the more essential in that

unavoidable desynchronization createsfatigue in many situations in modern lifenight work (total inversion of the cycle),work in revolving shifts (continuous andprolonged desynchronization), east/westand west/east travel (involving almost con¬tinuous desynchronization for certain per¬sonnel), life around airports and other siteswith high sound levels, work in exceptionalsurroundings (missile silos, tanks, sub¬marine-spotting aircraft, nuclear submar¬ines, spacecraft and space laboratories).

Finally, when the organism is syn¬chronized (that is to say, when it is subjectto the normal circadian rhythm of twenty-four hours), the effect of many medicinesvaries according to the time of day that theyare taken. Consequently, any change in theperiodicity of the sleeping/waking cycle(resulting, for example, from an east/westor west/east jet flight) or of the organism'sother rhythms, could have repercussions onthe action of the medicine, altering or evenreversing its therapeutic effect.

MICHEL SIFFRE, French speleologist, devisedand carried out the first major experiments involuntary human confinement. These experi¬ments, effected in caves in France and the

United States, produced new information relat¬ing to biological rhythms, psychological time,sleep and dreams. He is the author of some 50scientific papers, 8 books and 5 films.

15

o

©

The desert as a way of lifeby Hamidou A. Sidikou

TO survive in a harsh world man has

no option but to adapt to thephysical and climatic conditions

of his environment. In doing so he mustdevelop strategies which are oftenreflected in salient features of his culture

and society.The peoples of Niger, and especially

the Tuareg, the Tubu, the Kanuri, theGuézébida and the Arabs who live in the

difficult conditions that prevail in the aridand semi-arid regions of the country, areno exception to this universal rule. Indi¬vidually and collectively, their way of lifeis influenced, if not determined, by theneed to adapt to the rigours of a climate inwhich the dominant factors are wide tem¬

perature variations, their duration andintensity.

Over two-thirds of Niger's total area of1,267,000 square kilometres consists ofdesert and semi-desert zones situated

between latitudes 15° and 23° North. Of

this vast expanse, the Ténéré Desert,bounded to the west and north-west by

the Air massif and to the north and north¬

east by high plateaux whose southern lim¬its are marked by impressive cliffs, itselfcovers more than 350,000 square kilo¬metres.

In these climatic zones, a combination

of factors related to rainfall, atmospherichumidity and seasonal temperature vari¬ations normally gives rise to four distinctseasons of varying length.

The rainy season, which lasts fromJuly-August to September, is short andirregular. When it does rain, the pre¬cipitation is often slight, but sudden vio¬lent storms are a threat to those whose

houses are made of low-quality earth con¬taining a large proportion of salts whichdissolve rapidly in the wet.

From the end of September to the endof October there is a short intermediate

season characterized by both a highatmospheric humidity level and very hightemperatures. This is followed by a dry,cold season lasting from November toMarch when an east wind, the Harmat-

Berber peoples living in Mali, Niger andother Saharan countries, the Tuareg havecreated an original civilization adapted tothe desert and its borderlands. In the

southern parts of the region, nomadicherding over vast areas is a way of lifeconditioned by the arid climate and scar¬city of water and grassland. Above, aTuareg of Niger and his camel.

tan, brings dry mists which are liable to betransformed into violent sandstorms, and

temperatures fall below zero at night.Finally, there is a hot dry season which

extends from March to June or July. Thisis the season of very great heat, with tem¬peratures reaching 45CC or more.

The maximum daily temperaturerange which is generally experienced atthe beginning and end of the dry seasonmay be as great as 20°C, while the rangebetween the absolute minimum and max¬

imum temperatures may even reach40°C, if not more. An extraordinarycapacity for adaptation is required of

16

peoples subject to such rigorous climaticconditions. This adaptation is reflected inevery aspect of their lives. The strategiesthey adopt are in many cases indissocia¬ble from the organization of society andfrom housing, clothing and diet.

In this setting, human activity is strictlyruled by the existence of watering places.Because they are so rare, they have greateconomic value and are decisive factors

in the determination of social status.

Three branches of human activitystock-raising, agriculture and manuallabour appear to be directly deter¬mined by the harsh climatic conditions.

Stock-raising activities not only fulfileconomic requirements but also meet theneed to adapt to the climate with its greatvariations of temperature. Camels andcattle are the main species raised, pri¬marily for the production of milk which isthe basic element of the diet. Since cam¬

els are more hardy than cattle, they canbe raised in wide open rangelands and areable to adapt more easily to variations insoil composition and grazing vegetation.

The available quantity of milk, whichserves as both food and drink, varies fromseason to season, and this is why two com¬plementary species are chosen for its pro¬duction. Thus camel's milk, which is

available in adequate quantities duringthe hot, dry season, is appreciated bothfor its very rich vitamin content and for itslow fat content, characteristics which are

thought to increase endurance and resis¬tance to hunger. It is also said to haveremarkably beneficial effects on eye¬sight. The absence or very low proportionof visually handicapped people amongpopulations whose diet is based on cam¬el's milk may be partly due to its highmineral content.

Camel-herders also engage in trans-Saharan trading. One reason for this isthe need to reconcile the differingdemands of life in complementary ecolo¬gical zones. Until it declined followingsuccessive droughts which decimated theherds and destroyed the vegetation onwhich they depended for grazing, the car¬avan trade, in which tens of thousands of

camels were still involved only a few yearsago, was of more than just economic sig¬nificance. It was one of many responsesto the particular environmental condi¬tions and perpetuated a whole way of lifethrough a wide-ranging network of socialrelationships.

Knowledge of the location of wateringplaces is a key factor in this way of life inareas where the water supply is a matterof fundamental and permanent concern.Agricultural activity is thus limited to thearea around oases where a permanentsupply of water is available. Date-grow¬ing is the mainstay of this irrigation agri¬culture adapted to the seasons. Dates,

An Inhabitant of Bilma, a large town in ©Niger, carries loaves of household salt for sfamily consumption. £

17

which are an important item of trade withthe regions to the south, are a source offood, according to their quality, for bothman and beast.

Manual labour is primarily concernedwith the exploitation of salt and natron.The latter, a hydrous sodium carbonate,is an essential element in animal feed

since it meets the animals' salt require¬ments and also rids them of

intestinal parasites, thus boosting theirmilk production.

The concern to adapt diet to environ¬mental conditions, which always under¬lies human behaviour, is also apparent inthe unusual, some would say immoder¬ate, consumption of tea. A beverage thatboth quenches thirst and staves off hun¬ger, tea is served ceremonially. It plays apart in creating physiological mecha-

Saltpans at Tegguidan-n'Tessoum, Niger.Salt is produced by solar evaporation ofthe brine in each pan. Workers' legs arecovered with ulcers caused by walkingknee deep in the brine.

nisms for adapting to the variations intemperature.

Dress is another important indicationof adaptation to the environment. Thewearing of the veil and the turban are notonly of social significance (attainment ofadult status, for example), they also serveto protect the head, and in particular theeyes, nose and ears against the effects oflow temperatures, the stinging blast ofhot or cold winds and sandstorms. The

wearing of voluminous clothing, usuallymade of cotton , is a form of adaptation tohigh temperatures.

Finally, housing, its conception, thematerials used in its construction, and theuse made of it in relation to the seasons, is

another important element in adaptationto climatic conditions. In the Kawar

region of Niger, for example, where, inpast centuries, fortified villages were con¬structed for security reasons, four maintypes of dwellings are found.

Stone houses, the last relics of those

troubled times, are used during the dry,cold season because they offer betterprotection against sharp drops in tem¬perature.

Finding, transporting and storing water isa major preoccupation for Saharannomads. Right, women of Niger carrywater in gourds, an indication that theybelong to a semi-sedentary village (sincecaravaners use water containers made of

goatskin).

During the hot, dry season, housesconstructed of date-palm leaves comeinto their own. Cool, airy and well ventil¬ated, they are divided into rooms desig¬nated for different functions. A room

reserved for the head of the household

adjoins the entrance; there is a room forthe women and children, a store-room for

food or for animal fodder, a kitchen, and

a living-room in which meals are taken .Tents, which are made of skins or of

rush matting, vary in size according to themeans of the occupants. They are alwaysput up on a north-south axis with one ortwo openings on the east and west sides toallow air to circulate and the rays of thesun to enter. Tents are all-the-year-rounddwellings which can easily be dismantled.

©

L ÜL 4 ri^f

-*-

They are set up on top of dunes during thehot season and in spots protected byvegetation among the dunes in the coldseason. The tent is the perfect exampleof a dwelling fully adapted to the climate.

Straw huts, whose dimensions varyaccording to economic considerationsand to the availability of straw, itselfdependent upon rainfall, are used both astemporary shelters and permanent dwell¬ings. In the latter case they are usedmainly during the rainy season and in thehot season since they offer the best pro¬tection against rain and great heat.

These are some of the strategiesdeveloped by the peoples of Niger wholive in very hot desert areas. Their pur¬pose is to provide a minimum of comfortby adaptation to temperature conditionswhich remain, throughout the year, amatter of primordial concern.

HAMIDOUAROUNASIDIKOU.oM/ger./scon-sultant to several international organizations,including Unesco, and permanent secretary ofthe Committee responsible for developing aRural Code for Niger. A geographer, he taught atthe Faculty of Letters, Human Sciences andPedagogy of the University of Niamey (1974-1981), before directing (1981-1985) the Univer¬sity's Institute of Research in the Human Sci¬ences.

Loading a camel with its cargo ofsalt in thesandy plain of Ténéré. Salt is a vital com¬modity for man and animal in the desert,where it is still transported by camel car¬avans and serves as a form of currency.

19

Hunter-gatherersof the tropical forest

by Laurentiu Palade

Between 100,000 and200,000 Pygmies livein equatorial Africa, scattered through theforest which extends from the Atlantic

Ocean to the great lakes of the east.Remarkably well adapted to conditions inthe tropical forest, they live byhunting andgathering. Below, a Uganda Pygmy hunterwith animal hides for use as drumskins.

Beating drums is a form ofcommunicationbetween isolated groups in the forest.

TROPICAL forests form a greenband around the Equator,extending roughly 10° North and

South. This means that they account foronly a small proportion, about 8 per cent,of the Earth's land surface. Yet they com¬prise almost half of all growing wood onthe face of the planet, and harbour atleast two-fifths of Earth's plant and ani¬mal species, a genetic resource of increas¬ing importance to humanity through agri¬culture, medicine and industry. They alsocomprise the most complex and diverseecosystems on Earth, which fulfil regula

tory and productive functions that areessential to man and to his natural

environment.

The question of human adaptation toconditions in tropical rain forests hasbeen examined in a number of scientific

studies on groups of hunter-gathererssuch as the Pygmies. The existence ofsuch peoples is recorded in ancient times.Representations of them dating backover 4,000 years are found on ancientEgyptian bas-reliefs from the tombs ofpharaohs of the Vth Dynasty. They arementioned by Homer in the Iliad as well

m

w*£

Source: Nature and Resources, Unesco, 1 983

Moist, dense, broad-leaf evergreen forests with many epiphytes ("airplants" growing non-parasitically on trees and other plants and derivingtheir nutrients from the air)

i/y- ~: Drier, more open, partially deciduous forests with relatively few«¿xiia epiphytes

World distribution of tropical forests

as by Herodotus and Aristotle. Yet whileother civilizations have completely disap¬peared, the Pygmies, living in perfect har¬mony with their environment, have sur¬vived the ages.

Pygmies are to be found in most of theworld's tropical forests. They are fairlynumerous; the Ituri Pygmies of Africa,for example, number some tens of thou¬sands. Operating in small groups of fromfive to thirty-four individuals, they live asemi-nomadic life adapted to conditionsin the rain forest which are as extreme

and pitiless as those of the cold and inhos¬pitable Polar regions.

Light penetration of the forest canopyis minimal. Virtually all ultraviolet raysare screened out. The accumulated heat

and humidity is so intense that theatmosphere is like that of a greenhouse.The average temperature is 28°C, withvariations no greater than from 3°C to9°C. Average relative humidity is 95 percent at night and 60 to 70 per cent duringthe day, with only slight seasonal varia¬tions. Winds are also very light, exceptwhen there is a tornado, and the air isextremely rich in carbon dioxide and isladen with scent elements, formic vapouramd microscopic particles of hair, scalesand fibres. Rapid breakdown and trans¬formation of organic matter is ensured bymicro-organisms, which teem in the heatand humidity.

The level of évapotranspiration is veryhigh three times the average for theplanet as a whole. The forest floor is per¬manently moist and a protective layer ofbranches and leaves is essential should

you wish to lie on it. Ants and termitesabound. Like the flora, the fauna of theforest is rich and varied. Animal life is

"stratified", with different species livingat different levels. Monkeys and birds livein the higher levels of the canopy whereconditions are easier and food is more

abundant.

The tropical forest is not very generousto the people and the larger animals wholive at ground level. Food is difficult tofind and they sometimes have to be con¬tent with fruit that has been dropped bymonkeys. At night, the large predatorsventure out to the open savannah at theedge of the forest and to river banks and

abandoned cultivated plots. Game con¬sists mainly of small antelope. At thesame time, the inhabitants of the forestare under constant threat from insects,

parasites and arboviruses, a group ofviruses that develop in anthropods suchas mosquitoes and are then transmittedby bites to vertebrate hosts.

One indication of adaptation to forestlife is to be seen in the fact that forest-

dwelling elephant and buffalo are, in gen¬eral, half the size of their counterpartsliving in the savannah. The forest people,too, weigh less and are shorter than thosewho live in open country. A comparativestudy undertaken in Africa has shownthat forest-dwellers weigh, on average,39.8 kilograms and are 1.44 metres tall, ascompared with 62.5 kilograms and 1.69metres for inhabitants of the savannah. In

comparison with other populationgroups, their oxygen consumption during

effort, their pulmonary capacity and theircardiac rhythm are above average. Theyshow no signs of protein deficiency ormalnutrition.

Their small stature gives the hunter-gatherers of the tropical forest a definiteadvantage in the form of a relatively highwork capacity under difficult climaticconditions. A well organized routine,with major activities carried out early inthe morning or late in the evening, helpsthem to avoid excessive perspiration. Infact, despite the dampness of theatmosphere, they sweat very little. Ingeneral, they maintain a satisfactory stateof health and, among those who live in a

Pygmies in concert: this man from theCentral African Republic is playing a whis¬tle cut from a branch of the papaya tree.

21

Below, a Yanomamo Indian. The

Yanomamo, with a population of over15,000, live in the luxuriant tropical forestsof Venezuela and Brazil.

forest ecosystem which is still intact,there is a very low incidence of malaria.

In order to adapt to the constraints of alife of hunting and gathering in the forest,the Pygmies, like nomads, have had toreduce their material possessions to aminimum. Those they do have are easilyreplaced. All they need is a stick to digwith and a leaf to drink from; a hollowstem provi Jes a pipe for them to smoke.As a general rule they manage withoutanything that is too heavy to carry, suchas pots and pans and looms. The forestprovides them with liana, bark andbranches with which to built their huts,make their beds and clothe themselves.

They make strings for their bows andpadding for their shields from raffia fibre.From the hide of the game they kill theymake belts. They carve traps from rootsand make wicker griddles which, placedover a fire, enable them to smoke the

flesh of big game. Food is cooked in largeleaves.

Hunting, upon which the survival ofthe group depends, is traditionally a malepreserve. It has had a profound effect onboth the individual and the collective

mentality and has forged family andsocial structures. The forest is a foster-

mother who must be respected. It is tac¬itly accepted that no animal should bekilled or tree felled unnecessarily. Gameis usually caught with a net made of inter¬woven liana and its meat is shared out in

accordance with a strict ritual. Gather¬

ing, which is left to the women, is a com¬plementary source of food. The produceof the forest fruit, roots, leaves, mush¬rooms is abundant. Certain insects,such as caterpillars and termites, aregathered, as is honey. The forest alsoprovides products for bodily care and thetreatment of wounds, sickness and infir¬mities.

These forest people know theirenvironment to perfection. Far frombeing overwhelmed by their natural sur¬roundings, they are well organized andlead an active social life festivities, pal¬avers, dancing and have a culture richin tradition, myth and legend.

The uncontrolled clearing of tropicalforests for agriculture presents the forest-dwellers with problems of adaptation totheir changing environment and mayexpose them to health and other risks.The pathogenic agents found in a forestenvironment attack man more readily ina cleared area than in an intact forest,where they concentrate on the primateand rodent population. An increase inthe incidence of malaria, cardio-vasculartroubles, physiological ailments andnutritional imbalances has in fact been

noted.

The exploitation of forest regions con¬stitutes an indispensable economicdevelopment resource in many tropicalcountries. In order to achieve a judiciousstrategy which respects the natural bal¬ance, Unesco's Man and the BiosphereProgramme (MAB) is currently engagedon a project to study the ecological effectsof increasing human activity on tropicaland subtropical forest ecosystems. It ishoped that this project will help to answerthe many scientific questions raised byland use planning in the tropics.

LAURENTIU PALADE is a staff member of

Unesco's Division of Ecological Sciences. Afterfollowing an academic and scientific career inRomania, he spent several years in the humidtropics engaged on a Unesco/World Bank pro¬ject. The author ofover a hundred scientific stud¬ies, in 1983 he was awarded the EuropeanEnvironment Prize by the Goethe Foundation,Basel, Switzerland.

22

The sea within us

by Dan Behrman

Traditional method of tuna fishing off thecoast of southern Spain. As the shoals offish move from the warm Mediterranean

waters towards the Atlantic the fishermen

trap them in large nets stretched betweentheir small wooden boats. The giant fishare then hooked and pulled aboard.

THE sea flows inside us literally.In our blood as in seawater, the

proportion of dissolved salts is thesame: 3.5 per cent. Like all other forms oflife, we emerged from the sea, yet despitesuch links, our attitude towards it is

ambivalent. The sea inspires awe andfear, it is so unlike the landmasses that weinhabit. The vastness and solitude we

now associate with outer space havealways been present at sea. Even close toland, the surf waits to take its toll.

With the ending of the Ice Age 10,000years ago and the subsequent rise in sealevel, peoples everywhere found them¬selves driven back by the invading waters.

Peninsulas became islands, the land

bridge between Asia and North Americawas swamped and early coastal settle¬ments drowned on what is today's conti¬nental shelf. The story of the Flood isfound in cultures worldwide; perhaps dimmemories of the encroaching sea gavebirth to the legend of Atlantis sinkingbeneath the waters.

But the ocean gave life as well as takinglife away. Fish were plentiful and easygame; archaeological finds along thewestern coast of Europe include StoneAge bone fish hooks big enough to catchdeep sea fish. The seine nets, the trollinggear and the traps devised by the Inuit

23

©

*gM

mittens, for if he slipped, he was a goneman. All the boats were hoisted in on

deck and there was nothing to be loweredfor him. We had need of every finger Godhad given us. . . . Frequently we were obli¬ged to leave off altogether and take tobeating our hands upon the sail, to keepthem from freezing." Such Olympicexploits were part of the daily business ofmoving passengers and cargo.

Until the end of sail, a seaman's life wasa constant flirtation with death. And

now? Kipling's "call of the off-shore windand the voice of the deep-sea rain" canstill be heard, but can it be answered?

Hardly, on the automated tankers andcargo carriers of today. Noel Mostert,author oiSupership, describes such a ves¬sel: "One felt the arid metal acreagespreading invisibly all around, and its

impact was one of menace: a mechanicaldesert of indefinable purpose imposedupon the sea's own emptiness, and withforms and shapes that had no reassuringfamiliarity; it was filled with wind signs,not those of masts and rigging but ofabandoned structures upon a plain, andthere was no comfort even from the sea."

Mostert perhaps saw his vessel as a pre¬cursor of unmanned ships of the future,sailing under remote control.

There are still those who must seek

the sea fishermen, oceanographers,divers and they are of a different breed.The attitudes of small-scale fishermen

have not changed over time. They stilllive in small egalitarian communitieswhere growth is not a goal and informa¬tion is shared in co-operative net¬works.

Above, the "Triton", an early breathingapparatus for divers, named after the sonof the sea god Poseidon. In Greek mythol¬ogy, Triton lived with his parents in agolden palace in the depths of the sea.

people of the Arctic in a similar cultureare still used by fishermen today, withlittle change in their basic principles.

Attitudes to the sea have been divided

since the earliest times. Some sailed for

trading purposes, endeavouring to spendas little time on the water as possible and,at first, to stay within sight of land. Theybelonged to the civilizations huddledaround the Mediterranean. Then there

were the sea-peoples, the dwellers on theocean, who sought the sea, who returnedto its womb.

They did not shrink from the sea butembarked upon it in frail coracles or out¬rigger canoes. And the sea repaid them.Its waves could be read to indicate the

proximity of land, in the wake of an islandbreasting the tidal stream. The skies toldtheir story by day and by night; therewere nearly always clouds over islandsand mariners set their course by the stars.Even birds could show in which direction

the land lay, and surf breaking on rocksover the horizon threw up a telltale haze.

Physical conditions on shipboard in thedays of sail were extremely hard. No onehas described a seaman's life better than

Richard Dana in his narrative Two Years

Before the Mast, published in 1840 andstill a classic. Dana signed on as an ordi¬nary seaman aboard a vessel bound forCalifornia around Cape Horn, anunheard-of move for a university gradu¬ate of good family. In a storm off CapeHorn, the sailors went aloft to take in the

mainsail : "We had tofist the sail with barehands. No one could trust himself to use

24

Right, two women aquanauts, a botanistand a zoologist, carry out an experiment,on fish behaviour as part of a U.S. marineresearch programme on the sea bed. Thescientists lived for two weeks in a 4-room

habitat at a depth of 15 m in the Caribbeannear St. John Island (Virgin Islands).

Left, a diver about to take the plunge fromHMS Tedworth, protected by the cumber¬some type of diving suit used in the1930s.

Sociologists observe that fishermentend to defer their pleasures and ritualizetheir risk-taking behaviour. Risks thereare: the death rate of fishermen is seven

times higher than the average. And theyare a vanishing species, as boomingleisure activities encroach on their

beaches and shellfish beds.

Not all fishing fits these descriptions.Big trawlers are more like factories, asWilliam W. Warner points out in DistantWater: "Not since the great age of whal¬ing have men stayed at sea for suchprotracted periods . . . and no whaler ever,suffered the continuous and exhaustingwork schedules of the modern distant

water fisherman." Despite their size,these ships fell victim to storms,especially in winter when they were topheavy with ice. Adoption of200-mile eco¬nomic zones shut them out of rich shelf

waters and rendered them obsolete.

Warner sees a future with smaller

medium-range ships such as "autoliners"that can handle 15,000-hook lines

entirely by machine.Oceanographers are another variant of

the human species found only at sea: notonly must they survive aboard small shipsbut they must do scientific work as well,collecting data with precision. I oncewent out on an Icelandic research shipand took my turn taking Nansen bottles'off a wire as they were winched in. Allwaste motion had been eliminated fromthis series of movements that had to be

repeated tens of times a day, hundreds of

times a voyage. The captain, his bigtousled head stuck out of the port windowof the bridge, made a special effort tokeep the wire within my easy reach. Withthe help of propellers and rudder, hecould move his 800 tons of ship literally bythe inch in the empty grey water.

I thought of the oceanographer on thisvoyage, Svend Malmberg, reading thethermometers on his Nansen bottles to an

accuracy of a hundredth of a degree,when I came across an account of the

contrasting life on board an oil rig 200kilometres out in the Gulf of Mexico with

four 2,000-horsepower generators roar¬ing night and day. Crew members workedseven 12-hour shifts on this platform,then hoped that bad weather would nothold up their relief. Drilling for oil isprobably the least nautical of all occupa¬tions pursued at sea, but it is not neces¬sarily the safest. Oil rigs cannot run froma Gulf hurricane or a North Sea storm.

Divers, too, are essential to these cities

on the sea when it comes to finishing up awellhead or troubleshooting on the bot¬tom. One of the oldest of the maritime

trades is here put to good use by one ofthe newest. Divers were going down forpearls in the Babylonia of 4,500 yearsago, using the breathhold technique thatnow allows them to stay under for 4 min¬utes at depths of up to 45 metres (therecord for such diving is 90 metres).

In the nineteenth century, diving suitsfed by compressed air from the surfacewere invented, allowing divers to spend

more time on the bottom but bringing inthe danger of the bends, that painful andpotentially fatal condition engendered bynitrogen bubbles forming in the blood.Now that man was moving in this totallyalien environment he had to adapt to it,to the lack of oxygen, to the cold, to thedistortion of vision by water pressure onthe eyes.

He did this with the hard-hat diver's

suit invented in 1819 by a German engi¬neer, Augustus Siebe, that still left thediver attached to the surface. Then in

1942, the Frenchmen Jacques Cousteauand Emile Gagnan came up with theirindependent breathing device, the Aqua¬lung, and the scuba2 diver was born. Herewas a new animal, free-swimming into thedepths.

It was soon apparent that manypsychological and physiological adjust¬ments had to be made. Nitrogen underpressure in the divers' air led to "raptureof the deep" or the so-called "martinieffect" (each 15 metres of depth equalsone dry martini). An oxygen-heliumbreathing mixture took care of this butcreated new problems: a high-pitched"Donald Duck" voice and extreme

cold.

Diving tables were developed to show

1. Metal water-sampling bottle equipped with closingvalves and a mercury thermometer to record tempera¬ture at specified depths.2. Scuba = self-contained underwater breathingapparatus

25

how much time was needed in

decompression for a stay at a given depth.Once a diver is "saturated" at his depth,the decompression time is the same nomatter how long he stays there. Under¬standing of this principle led to the firstattempts to colonize the sea floor, theunderwater habitats of the 1960s and the

1970s. Unlike man-in-space missions thatdemand rocketry within the capability ofonly a few nations, man-in-the-seaexperiments could be carried out by anumber of countries. Among them wereFrance, the United States, the SovietUnion, the German Democratic

Republic, the Federal Republic of Ger¬many, Israel, Poland, Czechoslovakiaand Canada (which set some kind of arecord with an "underwater Volks¬

wagen" costing only $15,000).The, French were first to develop a

manned underwater station, with Cou-

steau's Conshelf, then the U.S. Sealab

was constructed. All sorts of problemsarose in the habitats. Humidity gave riseto infections, particularly in the ear, andwounds were slow to heal. Cooking couldbe tricky dough just will not rise in ahigh pressure environment and if a can offizzy drink is opened the bubbles goinward. (Some habitats solved all this byhaving their meals sent down from thesurface in containers.) Cuisine may notbe all that important, since many aqua-nauts reported a loss of their sense ofsmell and taste.

It has been found that during the firstfive days of habitat living, people showsigns of stress which then go away only toreappear after fifteen days. Life underthe sea is shipboard or submarine life car¬ried to an extreme. Like space travellers,aquanauts occasionally resented "groundcontrol" at the surface with its constant

monitoring of their behaviour. The tele¬phone could be a hated intruder, con¬stantly interrupting their routine.

And people had to get on welltogether. In one habitat, scientists at firstfound themselves at odds with seamen

doing simulated salvage work, but theyironed out their differences. Everyonewould probably agree with the Sovietsaboard Chernomor, who in 1971 reportedin the newspaper Izvestiya: "Thepsychological problems caused by theconfinement of several men together forlong periods of time was of great concernbefore the start of the programme . Underthese conditions it is well-known that

men may tend to find fault with eachother, that a man's silence may be taken

for sullenness, a very neat man may beaccused of being fussy. ... There weresome problems aboard the Chernomorduring the first few weeks but soon thecrew came to appreciate the abilities ofthe other members and no new problemsarose."

There have been no recent experi¬ments in underwater living. Instead ofremaining on the bottom, divers can nowbe brought to the surface in personnel

transfer capsules and live in pressurizeddeck chambers until they go down again.But there will always be underwaterexplorers, just as there were navigatorson the surface. Perhaps they will benefitfrom that ultimate transformation, the

invention of an artificial gill throughwhich the diver's blood will flow and take

up oxygen from the water, as fish do.Then the age of the sea people will have

truly begun.

DAN BEHRMAN is an American author and

journalist who frequently contributed to theUnesco Courier during his many years as aUnesco science writer. He is the author of a

number of books on oceanography includingThe New World of the Oceans (Little, Brown andCo., Boston) and Assault on the LargestUnknown, The' International Indian Ocean Expe¬dition 1959-65 (Unesco, 1981).

An engineer makes a tour of inspectioninside one of the legs ofa naturalgas drill¬ing rig in the North Sea.

26

Stress in the modern worldby Lennart Levi

ACCORDING to United Nations

statistics, the world's urban pop¬ulation has doubled since 1950

and may double again by the end of thiscentury, by which time three-quarters ofthe population of developed countriesand one-third to one half of the popula¬tion in developing countries will be livingin cities. Current estimates suggest that asa result of both population growth andmigration, the number of poor peopleclustered in slums and shanty-towns isincreasing annually by 10 to 15 per cent.Conditions in these places are appalling.The result is tension, depression and vio¬lence superimposed on physical hardshipand a constant threat of disease.

According to the Athenian statesmanPericles (495-429 BC), "health is thatstate of moral, mental and physical well-being which enables man to face any crisisin life with the utmost facility and grace".This ancient, definition, highlights twocritically important points: firstly thathealth concerns man's interaction with

his living conditions, and secondly that hemay lose his capacity to adapt if the lifecrisis is severe enough.

Much more recently, this insight hasbeen echoed in the terms of a Swedish

measure, the Public Health Service Bill

(1984-1985), which declares that "Ourhealth is determined in large measure byour living conditions and lifestyle. ..."The Bill goes on to state that "The healthrisks in contemporary society take theform of, for instance, work, traffic and

living environments that are physicallyand socially deficient, unemploymentand the threat of unemployment, abuseof alcbhol and narcotics, consumption oftobacco and unsuitable dietary habits, aswell as psychological and social strainsassociated with our relationships andlack of relationships with our fellowbeings."

The Bill strongly advocates what iscalled a "holistic approach" to such prob¬lems and attempts to solve them, mean¬ing that "people's symptoms and ill¬nesses, their causes and consequences,are appraised in both a medical and apsychological and social perspective".Bearing this in mind, let us look at someof these possible "causes" in the humanenvironment, including some of those inthe world's major cities in developing anddeveloped countries.

According to recent United Nationsand World Bank statistics, half of thecountries of Africa and southeast Asia,including four of the five largest, with acombined population of almost 2,000 mil¬lion, have an annual median per capitaincome of less than $300. This mass pov¬erty leads to hunger, undernourishmentand malnutrition for vast legions of chil¬dren in the developing world.

In the worst of cases, children die. In

the "best" of cases, they grow up withphysical and mental disabilities. Whenthey reach sexual maturity, therefore , it iseven more difficult for them to plan theirfamilies and care for their children, whothen become even more malnourished,even more disabled, and even less com¬

petent to care for the following genera¬tion of children. Thus a descending spiralis created causing morbidity, death andsuffering for hundreds of millions more inthe poor countries of the world.

According to recent UNICEF reports,in the developing countries 15 millionchildren die annually before the age of

Poster, right, gives a telephone number ofSwitzerland's "Helping Hand" service,which offers those in despair the solace of"someone to talk to". The Swiss postoffice co-operates by providing the tele¬phone call free.

Participation in group activities within thecommunity, above, can be a way of over¬coming the social isolation which causeswidespread distress in modern cities.

five, most of them because of lack of

potable water, adequate nutrition andbasic hygiene. In many African and someLatin American countries, plagued byhunger and shortage of water, this meansalmost every other child.

The Food and Agriculture Organiza¬tion of the United Nations (FAO) and theWorld Bank report that at least 430 mil¬lion human beings are malnourished orundernourished. In the developing coun¬tries about 60 per cent of the populationhas no access to safe potable water; 75 per

27

cent has no access to basic hygienesimple latrines, ways to dispose of house¬hold rubbish, and personal and foodhygiene.

Only 19 per cent of the population ofthese countries has access to housing ofacceptable quality. Four out of every fivehouseholds live in miserable huts in the

countryside or in shacks made of burlap,cardboard and sheet metal in the slums of

the large cities. Public health services areavailable to less than 15 per cent of therural and urban poor.

Such conditions cause acute physicaland psychological and social stress bycreating threats to survival, health andwell-being, to self-esteem, to closeattachment to others, to the sense of

belonging to a valued group. Thesethreats can in turn provoke potentiallypathogenic reactions leading to furtherincreases in sickness and mortalityrates.

But causes of psychological and socialstress are also extremely common indeveloped countries, in all types of socialand economic systems. In the UnitedStates, for example, 13.7 million childrenhave unemployed or absent fathers. Oneout of three white and three out of five

black children will experience marital dis¬ruption before reaching the age of six¬teen. Most of them will grow up inwomen-headed families, which are six

times as likely to be below the povertylevel. In 1978, 17 per cent of all childrenin the United States under eighteen (11per cent white, 27 per cent Hispanic, 41per cent black) lived in poverty, i.e. inconditions of run-down housing, heavytraffic, overcrowding, risk of contagion,accidents, injuries, pollution, violence,abuse and neglect.

When people are exposed to stress-inducing conditions of this kindwhether it is a question of lack of controlover their lives, combined with excessive

demands, unsatisfied needs, expectationsthat cannot be fulfilled, overstimulation,

or role conflicts most of them experi¬ence "dysphoric" reactions such as feel-

Above left, an oral health clinic in Thailand. In the developing countries the provision otmedical treatment, vaccination and safe drinking water is an essential part of a globalapproach to environmental health risks which also takes into account other aspects ofthe "human ecosystem "such as malnutrition resulting from masspoverty. The Rheuma¬tic Heart Centre, established at the foot of the Great Pyramids at Giza, above right, cameinto being thanks to the initiative of a Cairo voluntary association.

In the developing worldsome 15 mil¬lion children die annually before theage of 5, mostly because of lack ofsafe drinking water, adequate nutri¬tion and basic hygiene. Left, Nigerhas launcheda community-orientednursing programme to improvechild health care. Below, monitoringthe growth ofa toddleratan open-airclinic in Nicaragua.

28

©

£

*

ings of anxiety, depression, uneasiness,apathy, alienation and hypochondria.

In Sweden, statistics produced by theNational Board of Health and Welfare

(1978) show that every third four-year-old has mental problems (with symptomssuch as bed-wetting, aggressivity, noctur¬nal fears). Every third adult suffers frommalaise, sleep disorders, fatigue, dejec¬tion or anxiety. Every seventh workingperson is mentally exhausted at the end ofthe working day. Every other man andthree women out of four will suffer from

pronounced mental decompensationsome time in his or her life up to the age ofsixty. Every tenth man has an alcoholproblem. Two thousand people commitsuicide every year, and 20,000 attempt todo so (in a population of 8.3 million).

Taken together, these figures meanthat approximately every third or fourthSwede lives a life in which malaise, anx¬iety, fatigue or dejection is a commoncomponent. Moreover, the situation did

not improve from 1968 to 1974, in spite ofa considerable increase over this period inmaterial wealth and social security. Thisrather alarming picture assumes a furtherdimension when related to the ambitious

goals and very considerable materialmeans of the Swedish welfare state.

According to studies recently sum¬marized by the World Health Organiza¬tion (WHO), there are at least 48 milliondrug abusers in the world. But this is onlyone example of stress-related pathogenicbehaviour. Others include tobacco

dependence, quoted as the primary causeof one-third of all cases of cancer, 75 percent of chronic bronchitis and 25 per centof myocardial infarction in the UnitedStates.

As well as reacting emotionally to thestresses and strains of modern life and

behaving in potentially disease-provok¬ing ways, we also react physiologicallywith our internal organs. Coping withstress influences basic physiological reac¬tions in our central nervous system as wellas our ductless (endocrine) glands. Thebiologically active agents of the glands,

Air pollution (above) Is only one of manypressures in modern industrial societythat impose strain on the organism,adding to the tensions that have alwaysbeen part of human life.

Below, for millions of people living in theslums and squatter settlements of thegreat cities of the developing world, life isprimarily a struggle for survival as theyseek to protect themselves from cold,heat, hunger, disease and dirt. What theywant is decent housing in an environmentwhich will harm neither their lives nor their

dignity.

29

the hormones, together with nervousimpulses, influence virtually every cell inthe organism. If prolonged, pronounced,or recurrent, such reactions can eventu¬

ally lead to physical ill health.A WHO report (1986) also mentions

the high prevalence of somatic symptomsresulting from psychological and socialdistress, i.e. in cases with no ascertaina¬

ble organ pathology, or with complaintsof discomfort disproportionate to thephysical problem. This accounts for from30 to 50 per cent of all consultations indeveloped countries and for from 15 to 25per cent of those coming to the attentionof health care personnel in developingcountries the largest single complaintcategory in primary care.

Altogether, the resulting conditionsmake for extreme and ever greater suffer¬ing for over one-quarter of mankind. It istrue that people can adapt even toextreme environmental influences. Yet,

as indicated above, this adaptation takesits toll in terms of emotional, behavioural

and/or physiological deformation.Although a cause-effect relationship isdifficult to prove in specific cases, circum¬stantial evidence supports the existenceof such a relationship.

In developed and developing countriesalike, governmental action against suchproblems is often of a troubleshootingnature; it addresses only one or a fewspecific problems. It may include theprovision of medical treatment, vaccina¬tion, food shipments, or wells of potablewater. Not infrequently, it takes the formof acute disaster aid in situations where

disasters are usually chronic. In suchcases, intervention is usually admin¬istered by one of many specialized agen¬cies, with no or insufficient co-operationwith other specialized agencies. Onehealth problem say, ill-health caused bypollution may therefore be attacked,while another, such as poverty-inducedundernourishment, is neglected, or viceversa.

This brief, oversimplified account illus¬trates the existence of many interactingand pathogenic factors in the human eco¬system. If one of its components is influ¬enced, effects will occur in many of theothers. Consequently, it will probably beimpossible to cope successfully with cur¬rent and future urban and health prob¬lems by considering in research,therapy and/or prevention just one ortwo of the components of the total eco¬system. Success will be more likely if asmany as possible of the critical ones canbe taken into account.

LENNART LEVI, of Sweden, is professor ofpsychosocial medicine at the KarolinskaInstitutet in Stockholm, where he is chairman ofthe Department of Stress Research at the WorldHealth Organization's Psychosocial Centre. Heis also director of the National Swedish Institute

for Psychosocial Factors and Health (IPM) inStockholm. His many publications on stress, .health andpreventive medicine have been trans¬lated into several languages.'

Solo to the PoleAn interview with Jean-Louis Etienne

On 11 May 1986, forty-year-oldJean-Louis Etienne, a French

nutritionist and doctor specializingin the care of athletes, reached theNorth Pole after a solitary hike last¬ing sixty-three days. Wearing cross¬country skis and pulling an ultra¬light sledge, he had covered 750kilometres in temperatures as lowas -52°C and in winds of up to 100kilometres an hour. The Unesco

Courier talked to him about his

exploit.

What motivated you to undertake your soli¬tary walk to the North Pole? Was it the

challenge of a great sporting achievement,

or was it the scientific interest of an experi¬ment designed to measure the limits ofhuman resistance in an extreme environ¬

ment?

It was neither. The fact is that such motives

are often advanced to give respectability toa taste for adventure, a love of open spacesand the pleasures of discovery. There isreally no need to go such a long way just tocarry out a scientific experiment. It wouldbe perfectly possible to set up a cold cham¬ber right here in Paris and live in it for three

weeks, or two months, at a temperature of-47°C. For me, to go to the North Pole was adream, just as earlier I had dreamed ofclimbing Mount Everest, rounding CapeHorn, or sailing round the world. It was alsoa human and, above all, a technologicalchallenge.

What exactly do you mean by that? Whatequipment did you take with you?

The North Pole is located in the centre of an

ocean of ice, the Arctic, but it is no skatingrink! The terrain is very uneven. The ice iscracked, sheets are superimposed on sheetsor collide and compress to form ridges. Youcan never see the horizon, and your pro¬gress is constantly hampered by the icewhich can be completely churned up forkilometres on end. It is rather as if youdecided to cross Paris in a straight line bywalking across the roof-tops. What is more,this extremely difficult terrain is onlyaccessible for about two months of the year,between the beginning of March, when thePolar day dawns, and mid-May, when theice-pack begins to break up as summerapproaches. It is a real race against time,and to travel fast you have to travel light. Toequip myself for this undertaking I madeuse of materials that have the best low-tem¬

perature performance. With the aid of an

30

v¿ií» wi ,

K

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engineer friend of mine , I perfected a sledgemade of Kevlar, a light but very tough poly¬mer which is being increasingly used inaeronautics. The sledge was 2.20 metreslong by 60 centimetres wide and weighed 3kilograms. I managed to get the load downto 50 kilograms. To keep my bearings on theice-pack I carried with me a small Kevlar-encased safety-beacon-cum-radio-emitter,the signal from which was picked up bysatellite and transmitted to a computer atthe Centre National d'Etudes Spatiales(National Space Studies Centre) inToulouse, France. Michel Franco, who was

acting as my back-up at our base camp atResolute Bay on Cornwallis Island in the farnorth of Canada, questioned the computerby telephone every evening and theninformed me of my position. The beacon-emitter was powered by lithium batterieswhich are capable of withstandingextremely low temperatures.

Did you also use a compass?

No. The magnetic pole, to which compassneedles point, is some 1,500 kilometresfrom the geographical pole through whichpasses the axis of rotation of the Earth, andit was to this "true" North Pole that I was

heading. Furthermore, compasses are dis¬oriented by the magnetic fields in thisregion. Here the sun is the only guide. Itherefore had a watch made on which the

hour hand made only one complete revolu¬tion in twenty-four hours. Knowing that thesun is in the east at 0600 hours, in the southat 1200 hours, in the west at 1800 hours and

On his expedition to the North Pole Jean-Louis Etienne took specially designedlightweight equipment weighing 50 kg,left. His sledge weighed only 3 kg.

in the north at 2400 hours, all I had to do to

find my bearings was to point the hour handin the direction of the sun.

Why did you travel on skis?

Skis are indispensable. The ice-pack isfractured and there are crevasses every¬where, into which it is easy to fall unless youtake great care. Skis enable you to crossthem. In most places the ice-pack is from 2to 3 metres thick, but where it breaks the

water freezes again forming a very thin skinof ice. Skis spread your weight over a largersurface and enable you to walk over veryrecently-formed ice. I used nordic cross¬country skis to the undersides ofwhich I hadstuck synthetic anti-slip skins. In the past,people used sealskins for this purposebecause of the rigidity of the seal's body-hair which enables it to climb on ice without

slipping. When, once a fortnight, MichelFranco brought me fresh supplies by aero¬plane, he would also fit me out with newskins.

What did you have to eat?

Drawing on the recorded experience of pre¬vious polar expeditions, I had concoctedsome special food rations. At the beginningI allowed myself a daily ration of 4,000 calo¬ries. However, this proved to be insufficientand I was somewhat hungry, so I stepped upmy daily ration to 5,000 calories. My mealsfor a day were vacuum-packed in bags ofabout 1 kilogram. As this was dried food Iwould melt some ice to go with it (onlynewly-formed ice is salty; old surface iceloses its salt by gravity). I would heat up thewater on a petrol cooker (at those tempera¬tures gas is unusable) and pour it on thedried food to produce a kind of porridge. Inthe evenings my supper consisted of soupand a freeze-dried pre-cooked dish.

The surface of the ice-floe is rugged. Theblocks of ice fracture, collide against eachother and impact to form walls extendingover several km.

Did you also draw on the cold weather sur¬vival techniques of the inhabitants of the far

north? Did you, for example, dress in theirfashion?

Not at all. These people are hunters wholive in encampments, do not travel far anddo not go in for comparable, long-lastingphysical or sporting activities. They are notinterested in the North Pole, where there is

nothing and where life is not possible, andthey have never been there. In this they aresimilar to the Nepalese who would notdream ofclimbing Everest. As far as dress isconcerned, clothes are now made that are

much warmer and much lighter than tradi¬tional Eskimo clothing. The clothes I worewere made of Qualofil, a synthetic fibrewith very good insulating qualities.

Your journey lasted sixty-three days. Canyou describe a typical day?

I used to get up at four in the morning andset off at six. I would walk for eight to tenhours a day, until about three or four in theafternoon. Then I would stop, switch on mybeacon-emitter and put up my tent. Afterthat I would have a snack and rest until

seven, when I would contact Michel Franco

by radio. After that I would write up my logbook, have my evening meal and go tobed.

Weren't you ever afraid that you might go tosleep in the cold and never wake up again?

No. When you are in good physical shape,as I was, you are always first woken up by

31

Nutritionist and medical doctor, Jean-Louis Etienne devised the contents of

compact rations to provide him with 5,000calories a day. The food was freeze-drledand vacuum-packed in numbered packetseach weighing 1 kg. Supplies were flown tohim every two weeks.

the cold. You only die of cold if you are ill,or tired for example, after being stuck forseveral days on a mountain ledge. In thatcase, after a long struggle, you getexhausted and there is a danger of fallingasleep for good.

Did you manage to warm yourself up in yourtent?

No. The temperatures in the tent variedbetween -52°C and -20°C. I had to take

great care, before going to bed, to brush offthe frozen perspiration which covered melike a skin under my watertight clothing andwhich could, during the night, have broughton a chill. I used to make myself a hot waterbottle with a 1-litre aluminium bottle which

I would fill with boiling water and holdagainst myself inside my sleeping-bag.

Did you suffer from solitude in those vast

frozen expanses?

Solitude is not a handicap, it is a fantasticforce which enables you to bring all yourresources fully into play. Going to theNorth Pole is no joyride. You have to be onthe look-out all the time. You have to pickyour route and avoid falling and injuringyourself. You are living permanently on therazor's edge. At the same time, however,you can give free rein to your imagination.Blocks of ice are transformed into mountain

peaks, into towers or cathedrals. Some¬times I would say to myself: I shall go on tothat house ... to that mountain ... After

about three weeks to a month, when youhave got into your stride and the landscapestarts to seem monotonous, other thoughtstake over. I have never thought so much

about my childhood and my family. Andthen there was God ... the God of the Arc¬

tic, the God of the Pole, of whom I

demanded right of passage. It was, as itwe're, a sort of journey of initiation. Yet Inever felt any anxiety.

But did you feel fear?

Yes, twice. Once when I saw the tracks of a

bear, and then when the ice gave way undermy feet. My reflex was to fall flat on thesheet ice and to crawl. Only afterwards didI realize that I might have had a seriousaccident.

When you got back, did you undergo a seriesof medical examinations?

Yes. I had lost six kilograms. The mostimportant test was an evaluation of myadaptation to the cold. As I had done beforeI set out, I underwent tests in a cold cham¬

ber. I stayed in the chamber, naked, for twohours, in a temperature of 1°C and in anairstream of a speed of 8 metres per second ,which is the equivalent of a temperature of-10"C. My internal temperature and myconsumption of oxygen was then measured.Before setting out, over a period of twohours, I had maintained a temperature of37°C at the cost of a certain consumption ofenergy. On my return, it was observed thatmy temperature went down progressively to35.5"C before my body began to fightagainst the cold, and that my energy con¬sumption was considerably lower. In otherwords, I had become accustomed to livingat a below normal temperature and, fromthe point of view of energy expenditure, mytwo hours in the cold chamber had been

very economical. Like primitive man, orlike nomads who sleep in the open air, mybody's thermoregulatory mechanism hadadapted to hypothermic (low tempera¬ture) conditions. Thus, modern man,accustomed to high temperatures, canreturn fairly rapidly to the physical ther¬moregulatory comportment of his primitiveancestors.

Has this experiment of yours added to thesum of scientific knowledge?

From it I have gained a medical observationon human adaptation to cold, as well as anutritional study the rations I developedare now being used in France by the men ofthe Chasseurs Alpins Regiment and by par¬ticipants in the Paris-Dakar car rally. Thewatch I developed has been put on the mar¬ket and the tests using the beacon-emittersupplied by the Centre National d'EtudesSpatiales are considered to be conclusive. Ihave also worked with Professor Jouvet, of

Lyon, on the subject of sleep. In fact, con¬trary to all expectations, I slept very wellthroughout my journey. But it must berepeated that scientific research, and par¬ticularly medical research, should be basedon a large number of experiments. No validobservations can be based on a single case.Most of all, I have the impression that, inthe eyes of young people, I have taken overthe role of those who first aroused in me mypassion for adventure.

After the North Pole, you now plan to crossthe Antarctic.

This time I shall not be alone. I shall have

three travelling companions, two Amer¬icans and someone from the Soviet Union.

We shall also have two dog teams. We shallcross the continent, keeping in contact witha polar sailing vessel which will hug thecoast and transmit the pictures we shall besending. This expedition, planned for 1989-1990, will coincide with the expiry of theAntarctic Treaty (1961-1991) which regul¬ates the status of the Antarctic. We want to

focus attention on this immense territorywhich, under 2,000 metres of ice, contains

great mineral wealth which in four yearstime will belong to no one. It is our hopethat all industrial or strategic exploitation ofthe continent will be excluded and that it

will retain its international status and its

vocation as a land of scientific research.

Above all, our hope is that it will remain aland of silence.

32

Marathon Manby Bredo Berntsen

LONG-DISTANCE running hasenjoyed a popular revival inrecent years, and runners such as

Paavo Nurmi, Emil Zatopek, AbebeBikila and Grethe Waitz are household

names. But it was 150 years ago that thegreatest runner of all time was at the peakof his career. He was a Norwegian namedMensen Ernst.

His real name was Mons Monsen Oyri.He was the son of a poor tenant farmerfrom Leikanger on the Sognefjord wherehe was born in 1795. He lived there until

he was about fifteen years old, when hemoved to the town of Bergen. He went tosea, and won his first competitive run inCape Province in 1813.

As a seaman and adventurer he visited

the American, African, Asian and Aus¬

tralian continents, acquiring along theway survival skills that were later to helphim navigate, wheedle and bluff his waythrough his extraordinary journeys. Theonly surviving contemporary portrait ofthe "Running King", as he was known inNorwegian, shows him cradling a sex¬tant.

In 1818 he arrived in London. It is here

that he officially became a "pedestrian",a runner or walker who covered long dis¬tances in return for money. Here he alsotook his professional name, Mensen

Ernst. His subsequent career was to lastfor twenty-five years.

His first important run was in the springof 1819, from London to Portsmouth (116kilometres) in nine hours. His popularitywas assured when he then covered the 240

kilometres from London to Liverpool inthirty-two hours.

After a time he began to long for theContinent, however, and in 1820 crossed

the Channel again, travelling on foot toAnnenrode manor in Mühlhausen (inwhat is now the German Democratic

Republic), where he made a number oflife-long friends. From then on he lived asa professional runner, and his fame as the

greatest runner of all time spread quicklyas he ran from city to city Berlin,Prague, Rome across the Continent. In1826 he put on a demonstration inCopenhagen, where the high fees heearned included 100 "daler" from the

Danish King Frederick VI. Ironically, hisnative Norway was one of the few coun¬tries through which he never ran.

After some years Mensen Ernst cameto see himself as something of an interna¬tionalist. He became a genuine traveller,curious about foreign cultures andcustoms; he learned to speak French,English and German well, and knewsome Italian and Turkish.

The only surviving contemporary portraitof Mensen Ernst

In 1832, aged thirty-seven, Ernst wentto Paris in order to plan an audacious runto Moscow. Among those who helpedhim organize the stakes was a Swedishdiplomat, Count Löwenhielm. Ernst wasto receive 3,800 francs if he covered the

distance in fifteen days. He left Paris on11 June, arriving in Kaiserlantern twodays later. "I felt I was sailing ... on mytwo unique frigates," he was quotedlater, in a German book about him writ¬

ten in 1838. "Those who witnessed myrunning considered me eccentric, or elsea fool, or possessed by the devil."

On 18 June he crossed the Polish river

Vistula and next day was in Russia. Heactually reached Moscow a day earlierthan expected. The commander therehad prepared to greet him, but because ofErnst's early arrival and the ragged stateof his clothing he was taken at first for abeggar. He had covered about 2,500 kilo¬metres, or more than 170 kilometres

daily.How did Ernst adapt to the extreme

conditions encountered on his journeys,the burning sun, cold winds, pouringrain? We know that he had a strict set of

rules that he followed all his life. He stuck

to a simple diet, for example: mostlybread and cheese, a few vegetables, lessfrequently cold meat; but he never atewarm food. He also preferred to sleepoutdoors, believing that lying on hardground kept the body supple. If he didsleep indoors it was always on a hardbench, never a soft bed. His only weak¬ness was for wine, which he used to drink

by the bottle even on his runs, but with noapparent ill effects.

By the time he returned to Paris fromhis Moscow run, Mensen Ernst was a

hero. He had become a living legend whoattracted rapturous audiences of thou¬sands.

In 1833, he set out from Munich for

Old London Bridge in the early 19th cen¬tury, around the time when Mensen Ernstbegan his running career.

33

Nauplion, then the capital of the newlyfounded state of Greece. He suggested toKing Ludwig I and Queen Thérèse thathe carry documents for their son, Otto Iof Greece, and after a delay of somemonths his offer was accepted. His depar¬ture on 6 June was cheered by a crowd of20,000 outside Nymphenburg Palace.

This was a particularly dramatic jour¬ney, partly because of the rugged land¬scape, partly because of some unusuallysevere problems Ernst encounteredalong the way. In Montenegro he was setupon by five robbers wielding pistols andswords; as well as his money, they tookhis maps, compass and quadrant, but for¬tunately not the letters. He managed tofind his way to the town of Cattaro, wherehe got food and drink, new maps andcompass, and started out again only tobe arrested as a spy. He spent three daysin jail before he was freed by the Pasha ofJanina, who "looked more like a Western

general than an Oriental Pasha", as Ernstlater said.

ÍT///.'V.,-»rt- i

On 1 July he stood outside the King'sresidence in Nauplion to receive hisaward of 1,000 guilders. He had covered2,700 kilometres in just over twenty-fourdays. Allowing about four days' delay forvarious mishaps, he had done the run intwenty days, or about 135 kilometresdaily. These statistics are so extraordin¬ary that we are lucky to have contempo¬rary sources to verify them.

Ernst's third and most dramatic projectbegan with an offer by British merchantsof the East India Company in Con¬stantinople: £150 to carry important doc¬uments to Calcutta. He left on 28 July1836. The vigorous Norwegian hadthought the journey would take perhapssix weeks; in fact he did it in four, on a

route that took him through Anatolia,and finally across the Indian sub-con¬tinent.

On his twenty-eight-day return jour¬ney he took a more northerly route:Lahore, across Persia to the Caspian Sea,Teheran, Tabriz, and up to the Black

The desert near Theben, north of Syene(now Aswan) in southeast Egypt, wherethe great runner died from dysentery in1843.

Sea. He covered about 8,300 kilometres

in fifty-nine days, 150 kilometres dailyallowing for a three-day rest in Cal¬cutta.

The newspapers of his day praised hisachievement in completing the Asiatictour. The Times on 24 March stressed

"the unquestionable certificates" held byErnst.

His fourth epic run was to be his last. Itbegan when the German author, proprie¬tor and adventurer, Count Hermann von

Pückler-Muskau, thirty years beforeStanley and Livingstone, asked him tofind the source of the White Nile. Count

Hermann had a keen interest in runningstemming from a visit to Greece in 1837,when he had watched the Marathon and

heard about the Norwegian's exploitsfour years previously.

Ernst left the Count's estate in Prussian

Silesia on 11 May, 1842. He passed Con¬stantinople and reached Jerusalem inthirty days, and then ran the 500 kilo¬metres to Cairo. After some months in

Cairo he headed south along the Nile.But now his luck had run out. He suc¬

cumbed to dysentery on 22 January 1843,ending his legendary career in the desertnear Syene, now Aswan. Ten years later aNorwegian newspaper declared: "Theworld will never see his like again." Norhas it!

BREDO BERNTSEN, of Norway, is deputylibrarian at the University of Oslo. He is theauthor of a book about the life and times of Men-

sen Ernst, Loperkongen (The Running King",Oslo, 1986), and of many other articles andbooks including Naturvernets historie i Norge(1977, "The History of Nature Conservation inNorway").

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Different walks of life

Above, at an altitude of some 4,000 metres, a traveller and his pack-animals wend their way abovethe valley of Dolpo in the Himalayas (Nepal); below, a woman aquanaut carries out an experimentnear an underwater habitat in the Caribbean (see page 25).