Can pollution be controlled?

At the Stockholm Environmental Conference, in answer to environmentalists' demands for the banning of supersonic aircraft, Lord Zuckerman, ex-chief scientist to the British government, answered that

"If it were an ineluctable conclusion that the use of supersonic civil transport would irrevocably wreck the ozone layer which overlies our atmosphere, can we seriously imagine that we would not find ways of inhibiting the use of such aircraft, as our knowledge of their secondary effects, if any, become more apparent? What are we: ants, lemmings or rational human beings?" [1]

Lord Zuckerman appears to be living in a world of his own. Indeed the experience so far has been that very harmful pollutants have often been produced for a very long time before even their harmfulness has been noted, during which time they have entered into so many different manufacturing processes that they have become general environmental contaminants.

Even then, efforts to introduce any controls at all have been so feverishly opposed by industry and government with the aid of the scientific experts whom they employ, that still more time has elapsed before they have met with any success however limited. And limited they always have been. Indeed with respect to the control of pollution we have behaved very much like the legendary lemmings. Let us consider a few examples.

Polychlorinated biphenyls (PCBs) are today regarded as known carcinogens, also ones that appear to be toxic at much lower levels than previously thought. They were first brought into use in 1929. It was nearly 40 years before their environmental hazards were recognised. In the intervening years, 30,000 tons had been dispersed in the atmosphere, 60,000 tons into water systems and 300,000 tons had been dumped. [2]

If DDT can be transformed into PCBs, which seems to be the case under the action of ultra-violet rays, then the quantities are much bigger still. What is certain is that PCBs are now a general contaminant of our environment. They are present in water, air, soil and sediment and tend to accumulate in the fatty tissues of animals. [3]

DDT is now also recognised as causing serious biological damage to biological organisms and is a suspected carcinogen. Since it first entered into use the total amount produced is somewhere in the area of two million tons and, like PCBs, it is now a general environmental contaminant. Though its effects were revealed over 30 years ago with the publication of Rachel Carson's Silent Spring, no real action was taken until 1972. Today, even though it is no longer allowed to be sold in the US, exports are unaffected and it continues to be produced at around the rate of 100,000 tons a year.

Another general contaminant of life on this planet is vinyl chloride monomer (VCM), which is now a recognised carcinogen. Prior to the discovery of its hazards however, an estimated 100 million pounds a year were being lost to the environment during manufacture and 2 percent of the US output of five billion pounds was being released "through deliberate dispersive use", though the most hazardous of these uses, as a propellant in aerosol spray cans, was banned in 1974. [4]

The use of this pollutant is now subject to certain controls in many countries: however, its production in total terms has not been affected. In particular it is still used as a plasticiser for wrapping materials and is known to leach in small but significant amounts into the food-stuffs contained.

The carcinogenic effect of asbestos has also been known at least since the early 1930s. The time lag between first reports of asbestos-related disease and control measures to reduce the risk, was about 30 years. During this period, to quote Lawrence McGinty,

"The toll of death from cancers and lung disease caused by asbestos will never be counted. Some are buried with conveniently incorrect death certificates, others died from lung cancers indistinguishable from those caused by smoking cigarettes. Although asbestos is not the most potent toxic substance used industrially, its very pervasiveness means that the number of people exposed to it - workers, consumers, and those living in cities - is enormous. It would be quicker to count those who haven't been exposed." [5]

Other carcinogens such as red dye No.2 or amaranth, another established carcinogen, have entered into an astonishing variety of processed foods. In the US each year, about nineteen million dollars-worth of these have been produced and added to $19-25 billion worth of food. According to the Federal Drug Administration (FDA), amaranth was used in

"ice cream, processed cheese, luncheon meat, frankfurters, fish fillets, shell fish, cornflakes, shredded wheat or wheat cereal, rice flakes or puffed rice, rolls (sweets, cinnamon, Bismark etc.) snack items (pretzels, corn chips, crackers etc.) cookies, pie crust, cake-mix, pickles, canned peaches, citrus juice and other canned fruit juices, other canned fruits and fruit cocktails, salad dressings, jelly, pudding mixes, syrup, jam, candy bars, vinegar and cola drinks. [6]

Americans are said to have ingested about five hundred tons of it a year. The FDA attempts to ban it were delayed for 15 years. It has now been banned in the US but is still in general use in other countries.

Hexachlorobenzene (HCB) has been widely used as a fungicide for seed protection. World production is thought to be around four million pounds a year. It was found to be highly toxic as early as 1955 when grain seed in Turkey treated with HCB that was intended for sowing, was used instead for bread production. Five thousand people were affected by eating the contaminated loaves and between 250 and 500 died.

WHO has shown that children under the age of two taking HCB via their mother's milk, suffered a 90 percent mortality rate. In the US, HCB is a trace contaminant of human milk and levels are also to be found in other foodstuffs including butter. So far efforts to ban this substance have failed. [7]

Hexachlorophane is also a highly toxic chemical. In the summer of 1972, thirty-nine infants in a French hospital died from being rubbed with a baby powder containing 6 percent Hexachlorophane. It was banned by the FDA in January 1972, but only after being used for thirty years in a host of non-prescription products including 400 categories of deodorants, soaps, shampoos, toothpastes, cleansers, and cosmetics, involving thousands of brand names and hundreds of millions of dollars in retail sales. [8]

Chloroform was shown to cause liver cancer in small animals over 30 years ago, but it is still used in cough mixtures, mouthwashes and toothpastes. It is also used as a preservative. In fact it is now in such general use that when it was suggested to a UK expert that this substance might be banned he answered, "it would be like trying to get rid of alcohol - there is a little bit everywhere." [9]

It is important to realise that I have named but a handful of the four million chemicals which, according to OECD, we have introduced into our environment; 563,000 of these are thought to be in common use and a hundred are produced in excess of 50,000 tonnes a year. [10] It is also important to realise that very few of these chemicals have been properly tested - a question I shall examine in greater detail further on in this chapter.

It should thereby be fairly obvious that we live in a highly contaminated environment - and when we consider that possibly 1,000 new chemicals are introduced every year - some say 3,000 - and that the quantities of the existing ones generated by our industrial activities continue to increase with the growing world economy, our environment is clearly becoming more highly contaminated every year - which explains the current and growing epidemic of pollution-induced diseases, in particular cancer.

What is more, it is equally obvious that our efforts to control pollution are very ineffective - that we are, in fact, behaving much more like lemmings than like Lord Zuckerman's 'rational human beings'. Why should this be so?

The excuses

When the pollution caused by a particular activity or set of activities is pointed out to the polluters or to the authorities and it is suggested that something be done about it, the answer is nearly always the same. We are told that this is not possible until further scientific research is undertaken in order to obtain 'the hard scientific evidence' required to determine the exact effects of the pollutants on living things.

Consider, in this respect, the efforts made by Chemie Grunentaile (the firm responsible for making and distributing thalidomide) to avoid the banning of this product. Among other things, a famous expert, Professor Eric Blechschmidt, Director of the Institute of Anatomy of Gottingen University, was prevailed upon to state in a Court of Law that

"so long as there is no complete certainty about how the thalidomide might execute its effect on any embryo, theories about the drug's detrimental quality are premature and represent no more than pure speculation. Any binding thesis about a causal link between thalidomide and deformities does not yet exist." [11]

Consider, too, the efforts made to control the pollution of the Mediterranean. [12] The United Nations Environmental Programme sponsored a series of international meetings to try to reach agreement on actions required to prevent this sea from becoming a lifeless waste but so far these have been in vain. The excuse for inaction is, as usual, ignorance as to the exact nature of the pollutants which are causing all the damage.

"We do not have enough evidence yet," said Dr. Keckes, the scientist in charge of the 'scientific assessments' of the state of this highly polluted sea. "The rate of implementation of the Treaty will depend on how fast we can define the standards scientifically." [13]

Consider yet another example. The National Cancer Institute (NCI) has demonstrated the carcinogenicity of trichlorethylene which is used as an industrial solvent particularly for degreasing machine parts, in foodstuffs for de-caffeinating coffee and has been used by solvent abusers with fatal results.

In the UK, the Health and Safety Executive (HSE) however, refuses to reduce existing safety levels which are at present 100ppm. One reason is that the NCI tests were on animals and not on humans. This is a weak excuse, since substances which are carcinogenic to one form of life tend to be carcinogenic to others - the informational medium contained in the genes and in the nucleus of a cell affected by a carcinogen being expressed in precisely the same medium, DNA. Tighter controls, they insist, will have to await the result of surveys of workers exposed to this chemical.

What is more, a spokesperson has admitted that the government Employment Medical Advisory Service has no immediate plans for such a survey. [14] Indeed whenever we are told that no scientific evidence has been found to incriminate a particular chemical, the chances are that no one has bothered to look for the evidence. [15]

The question we must ask is how much can governments justify allowing several million chemicals, to which organisms and ecosystems have never been exposed during the course of their evolution, to be released into our environment without such tests being carried out? Greater irresponsibility is hared to imagine. But would carrying out such tests serve any real purpose? Would they yield serious information that could really be of use in determining an effective strategy for controlling offending chemicals? As I shall now attempt to show, the answer is undoubtedly no.

The theoretical basis of pollution control is provided by the principle that dangerous chemicals are only dangerous when used at sufficiently high levels and that there must be a level at which concentrations of the chemical are biologically harmless. If this is so then it suffices to ensure that these levels are never exceeded so that no biological damage to occurs.

The more we know about the biological effect of chemicals, however, the more it becomes apparent that this is simply not true. Serious efforts have been made to establish safe levels of different pollutants but these studies have always proved to be in vain.

This is the case, for instance, with radiation. It is now generally accepted that any increase in radiation levels during the course of our evolution must be reflected in some biological damage. The same seems to be the case with asbestos. The US National Institute of Occupational Safety and Health (MOSH) has stated quite explicitly that

"excessive cancer risks have been demonstrated at all fibre concentrations studied to date. Evaluation of all human data available provides no evidence for a threshold or for a "safe" level of asbestos exposure." [16]

In general this is true for all carcinogens, a principle that is accepted by the Health Education and Welfare (HEW) in the US. As its former secretary, Arthur Flemming, has said, "Scientifically there is no way to determine a safe level for a substance known to produce cancer in animals."

It is this principle that provides the rationale for the famous Delaney Clause which makes it illegal in the US to add any chemical to foodstuffs that can be shown to be carcinogenic, even in very small amounts. Since the Delaney Clause was passed no significant progress has been made in our ability to determine a safe level of a cancer-causing chemical. On the contrary, according to Anita Johnson, "recent evidence suggests that estimating a safe dose is more difficult than was previously thought." [17]

For instance the FDA conducted a massive 'megamouse' study at a cost of more than $5 million to determine if very low doses of a known carcinogen over a period were in any way safer than high doses, as is generally maintained by the chemical industry. 24,000 animals were used in this study and the results showed that low doses were not safe at all. Liver cancers were produced at the lowest dose as well as at the highest.

If this is so, then the acceptable levels fixed for potentially dangerous chemicals released into our environment have no scientific basis whatsoever. In fact, it is very easy to show that they are simply the minimum levels that can be achieved without compromising economic priorities.

Thus the WHO standard of 0.02 to 0.05 ppm mercury in food

"is simply the practical residue limit, the concentration of mercury expected in the diet from natural background and environmental contamination." [18]

In Sweden, the maximum permissible level was maintained at 1.00 ppm for a very long time. The reason is that if the limit of 0.5 ppm had been adopted in the late 1960s as was then proposed, it would have become necessary to close down more than 45 percent of Sweden's inland fisheries. [19]

The acceptable level of lead in drinking water is above that which tends to be present today. When WHO recently raised it from 50 microgrammes to a hundred microgrammes per litre, this was not the result of the sudden discovery that man was less sensitive to lead poisoning than was previously thought, but because few water authorities could provide water to this standard.

Indeed the Cox report, drawn up with the aid of experts from twenty-four countries, established that toxic effects are noted above fifty micro-grammes per litre - while Dr Kehoe who, according to Professor Bryce-Smith "has probably carried out more studies on lead than almost any other authority living", argued very strongly that the level should be set as low as twenty microgrammes per litre. [20]

The level fixed by the FDA for aflatoxins, highly carcinogenic substances produced by certain moulds left on improperly dried crops such as peanuts and cereals, is 20 ppb. Yet we know that aflatoxins can cause cancer in animals when fed at levels of 45 ppb to fish, 1 ppb to rats; while at 15 ppb aflatoxin, 100 percent of rats get cancer. As Anita Johnson points out, these very high tolerances are an indication of the commercial pressures felt daily at the FDA.

In the same way, the level set by the FDA for PCBs is 5 ppm in fish and poultry in spite of the fact that PCBs are so toxic that they have been shown to suppress reproduction in animals at a dose of 2.5 ppm. To quote Anita Johnson again,

"The FDA appears to have chosen 5 ppm simply because it would permit the vast majority of FCB-contaminated products to be marketed as usual."

Efforts to reduce permissible levels by various government agencies are consistently being thwarted by commercial pressures. The Department of Labor, for instance, was expected to announce a reduction in the acceptable level for occupational exposure to lead in the air, by 50 microgrammes per cubic feet of air. This would have reduced the existing level by four times.

The US Regulatory Analysis and Review Group opposed this on the grounds that the cost to industry of maintaining these levels would be in excess of $1 billion. New levels for exposure to benzene proposed by OSHA were also successfully quashed in the Federal Appeal Court in New Orleans on the grounds that the agency had failed to demonstrate "a reasonable relationship" between anticipated benefits and costs. [21]

International variations

Needless to say, acceptable levels vary considerably from one country to another, largely because of the different pressures exerted by government departments and commercial interests.

Thus, the acceptable level for Vinyl Chloride Monomers (VCMs) was for a long time 550 ppm in the US whereas it was only 100 ppm in West Germany and only 10 ppm in the USSR. This seems to have been largely because of the pressure applied by Goodrich, the principal manufacturer in the US, which strongly opposed the proposed new standard. (It was then reduced to 1 ppm over an 8-hour period with permitted excursions of up to 5 ppm over and above which respirators must be worn.)

This refusal to take any real action to ban carcinogens reflects standard government policy. Indeed the government boasts of its "flexible and pragmatic approach" whereby polluters are simply asked to keep pollution levels down "by the best practical means" - which, in practice, means in that way that interferes as little as possible with the far greater priorities of maintaining employment and economic growth.

Thus the International Committee on Radiological Protection (ICRP) recommends that all exposure to radioactivity

"be kept as low as reasonably achievable, economic and social factors being taken into account; and... the dose equivalent to individuals should not exceed the limits recommended in the appropriate circumstances by the Commission."

As Professor Athersley pointed out at the Windscale Inquiry, what this implies "depends on how 'reasonably achievable' is interpreted." [22]

At Windscale (now Sellafield), where levels of caesium and alpha emitters such as plutonium and americium to the Irish Sea are very much higher than they are from any other similar reprocessing plant, and where no efforts whatsoever are made to contain emissions of krypton 85 and tritium to the atmosphere, the term 'reasonably achievable' is clearly interpreted in such a way as to make it unnecessary for British Nuclear Fuels to incur any additional costs that might reduce this state-owned company's economic viability.

This attitude is reflected in all our government's pollution control policies. Thus the UK representatives at EEC discussions on the control of pollutants released into European rivers refused to accept the controls proposed on the grounds that our rivers were faster flowing and could therefore absorb more pollutants than could those on the continent. This is an absurd argument since the levels of pollutants entering our grossly polluted seas from our rivers, are in no way affected by the river's rate of flow. [23]

Individual variation

The most obvious problem involved in fixing an acceptable level for any pollutant is that susceptibility to different chemical substances varies from individual to individual, even more so from one age group to another. As Professor Schubert points out, the reason is often genetic and is related to the presence or absence of the enzyme needed to break down a chemical.

Children are particularly susceptible to most pollutants, foetuses even more so. Thus whereas adults appear to take up 10 percent of the lead that enters their body, the rest being eliminated, the figure for infants may be as high as 50 percent. [24]

The susceptibility of foetuses to damage by X-rays is well known. During the first three months of pregnancy when the organs are developing they are more susceptible to mutations and a dose of 500 millirads appears sufficient to double the number of cancers likely to develop within the first ten years of life.

The doubling dose however appears to increase to about 2,000 millirads if exposure takes place during the last six months of gestation when the foetal organs are growing. In general, cells undergoing rapid division as in the foetus and newborn baby are most vulnerable to carcinogens.

Individual variation is also related to domicile. People are more or less vulnerable according to their proximity to a source of pollution and, of course, it will vary even more in accordance with the work they are involved in, which may bring them into contact with pollutants of varying degrees of toxicity. Individual lifestyles are also very relevant; obesity and alcoholism may increase susceptibility to pollutants while eating and drinking habits affect resistance to chemicals that may find their way into different types of food and drink.

Diet can affect susceptibility to pollutants from whatever source because malnutrition weakens all the body's defences. Unfortunately all such variations in susceptibility to different pollutants are simply ignored.

Thus in the US, the FDA established an 'interim guideline' of 0.5 ppm of mercury in food. This is based on the assumption than an average serving of fish is 150 to 200 grams. It also assumes that the average American does not eat fish more than twice a week and, as a result, would not consume more than 0.03mg. of methyl mercury per day, which is the maximum safe limit. [25]

This may be all right for the average American, but everyone is not average. What happens to those people who happen particularly to like fish, or who live in an area near the sea where a lot of fish happens to be eaten, or who are professional fishermen, or married to fishermen? Is it right that they should be condemned to suffer the terrible consequence of mercury poisoning?

In Britain there is the same callous disregard for the non-average consumer. Thus, towards the end of 1970, studies began to show that fish at the top of the food chain such as tuna and swordfish, wherever they seemed to come from, were heavily contaminated with mercury. 900 million cans of tuna were taken off the market in the US because they contained more than 1 ppm of mercury.

In Britain, tuna on the market was found to contain similar levels of mercury. For a while, the public was advised not to eat it, but then, as Anthony Tucker points out, the government

"contrived to rationalise a course of inaction by resorting to averages. By counting British heads and the number of cans sold a year and by completely ignoring those who like tuna and eat a lot, the scientific advisory committee was able to arrive at reassuring conclusions." [26]

Mr Prior, who was then Minister of Agriculture, made this announcement at the end of the year,

The experts consider that it is the total intake of methyl mercury that is important... they consider that it is unnecessary at this time to withdraw from sale or to advise consumers not to eat any of the canned tuna now on the market. The tests have shown that all this fish is within the safety limit set in some other countries including Sweden. In short, there is no reason why the housewife should not buy it."

Critical groups

This iniquitous philosophy is clearly reflected in the UK in the concept of 'critical groups', i.e. of people who are particularly vulnerable to a specific pollutant. It is on the basis of the exposure of such groups, for instance, that the permissible levels for the discharge of radioactive wastes are calculated.

One such critical group, living in South Wales, is composed of local eaters of traditional laver bread, made from seaweed, which unfortunately, tends to concentrate radio-isotopes of various sorts and in particular ruthenium. Concentrations in the seaweed in the vicinity of the Sellafield nuclear installation are already above the permissible levels (in a recent test they averaged out at 370 picocuries per gramme of seaweed).

This, however, is not regarded as a cause for concern for the unbelievable reason that the Cumbrian seaweed comprised only a small proportion of that used in laver bread manufacture. Too bad of course for anyone who should wish to use more Cumbrian seaweed than the average for making laver bread.

But the situation is now even worse, for a few years ago the women who used to collect Cumbrian seaweed stopped work. As a result the laver bread eaters of South Wales are no longer considered to be a 'critical group' and the pollution of seaweed with radioactive waste is no longer of any concern.

If this principle were generally applied to determine permissible levels of all the pollutants released into our environment, we would be safe so long as we were average consumers of each contaminated foodstuff and, of course, so long as we did not change our habits in any way from year to year.

At the same time, if ever political, social, economic, ecological or climatic changes of any kind forced us to adopt new living, working, eating, drinking or breathing habits, we would then be exposed to dangerous levels of all sorts of pollutants that we would have previously not encountered in conforming to the authorities' model of the average person.

In other words, this present system involves constantly narrowing down our options for the future and hence reducing our capacity to adapt to changing conditions: a truly suicidal prospect. If our government were really concerned about the effect of pollutants, it is not for the critical groups of today that it would cater but for all the possible critical groups of an unpredictable tomorrow. This means that we should not be catering for the average person but for the maximum person.

Catering for the maximum person

There are two other very good reasons why in any case this must be so. Firstly, even if it is possible to be average with regard to exposure to a single pollutant, it is obviously not feasible to be average with regard to the 4 million or so pollutants that we have introduced into our environment.

In reality every single person is likely to be non-average, in some respects at least, and so to be subjected to more than arerage levels of one, and more likely, many pollutants. The fact is that the average person does not exist. S/he is but a figment of the statistician's imagination.

The second reason why we must cater for the maximum person, is that humans are not the only form of life on this planet. We cannot regard as expendable, and thereby justify systematically poisoning all the non-human forms of life that happen to inhabit the areas that humans do not exploit to satisfy their immediate requirements. We can only do so at the cost of causing serious ecological disruption with all sorts of unpredictable consequences.

Unfortunately, of course, to reduce pollution levels to the point required to protect the maximum person and living things in general from pollution damage, could only be done by compromising other priorities. The cost to industry would be too great - economic growth could no longer be maintained.

Measurements

A further problem is that it is difficult to fix levels below those that can actually be measured by currently available techniques, yet many pollutants may well be biologically active below this level. Thus Dr Sturgess of the Essex River Authority points to the damage done by a hormone weed killer in concentrations as low as one in a thousand million.

"Present methods do not even enable one to detect the presence of pollutants in this dilution, let alone trace them." [27]

The measurement of ozone concentrations in the stratosphere which are required to confirm or invalidate the thesis that it is being depleted by fluorocarbons and other chemicals emitted by our industrial activities, are only possible in a rudimentary way, since

"Available measuring techniques are too insensitive to detect small long term variations." [28]

Asbestos, even at levels of 0.1 fibres per cubic centimetre of air (the acceptable level proposed by the US National Institute for Occupational Safety (OSHA) ), is very difficult to detect and may still cause cancer, since the average worker doing an 8-hour shift would be breathing about 800,000 fibres into his or her lungs every day.

The difficulty in measuring asbestos pollution in the environment is illustrated by the experience of the now defunct Greater London Council's Environmental Sciences Group. Air samples taken by this group were sent to eight different commercial laboratories for analysis. Each one gave a different set of results. [29]

In the same way during the course of a study carried out by the French consumer magazine Que Choisir? a sample of human faeces to which a specific pathogen had been added was submitted to thirty-two commercial laboratories for analysis. Only one succeeded in detecting its presence.

Sub-lethal effects

For these and similar reasons it is only feasible to measure high levels of specific pollutants in our environment and low levels are simply assumed to have little effect on the health of human and non-human animals. This, of course, as already intimated, is a pure act of faith, based on no evidence of any kind.

On the contrary the more we learn about the biological effects of different pollutants, the more it becomes clear that exposure to low levels over a long period, can be as damaging, if not more so, as exposure to high levels over a brief period. This is certainly the conclusion of Dr. Waldichuck of the Pacific Environment Institute, as he showed in a paper he presented at a Royal Society Meeting on the effect of sub-lethal levels of pollution on marine organisms. [30]

Waldichuck points out that actions to control pollutants in rivers or the sea only tend to be taken after fish kills, i.e. to deal with acutely toxic conditions. It may be just as important to guard against low levels of pollution which, among other things, can adversely affect fish reproduction and thereby insidiously assure the decline and indeed the disappearance of fish populations.

These are very difficult to control, indeed, fish populations or even species, can disappear in many cases without anyone noticing it, all the more so in that natural fluctuations in fish abundance and changes due to fishing may obscure a decline in population caused by a pollutant.

There is already ample evidence of fish populations declining and even disappearing from polluted fresh water environments. Thus species of fine fish have declined very dramatically in the North American Great Lakes. The Atlantic salmon has disappeared from many polluted streams in Europe and eastern North America. The Pacific salmon has been affected in the western United States, while populations of other fish have declined and, in many cases, disappeared from acidified lakes in Scandinavia.

The sub-lethal effects of low-levels of different pollutants are best understood once we have adopted an ecological view of health.

Today, individuals tend to be regarded as healthy to the extent that they do not display clinical symptoms of disease but this is totally unrealistic. An organism must be regarded as healthy to the extent that it is viable, more precisely, to the extent that it is capable of dealing adaptively with environmental challenges. In this sense, health is synonymous with homeostasis or stability.

It can be shown that health can be impaired by all sorts of minor insults, in that these can reduce an organism's ability to deal with environmental challenges. This appears to be the view of Waldichuck. He shows many of the ways in which a marine organism's behaviour pattern, and hence its ability to survive, is impaired by low doses of different pollutants. For example, very small quantities of cadmium affect calcium metabolism with adverse effects on the equilibrating mechanism of fish. [31] This probably reduces the ability of fish to avoid predators and also their capacity to seek and capture their prey.

Very low levels of various pollutants, in particular of organophosphorus pesticides, inhibit enzyme activity, and can also impair hormone function. Different concentrations of copper and iron have been found to affect plasma cortisone and other hormones in Sockeye salmon. [32] Low levels of oil pollution have been shown to have serious effects on fish eggs, giving rise to chromosomal errors and gene-level mutations and, when these occur during the gastrula stage, they are almost invariably lethal

Low levels of pollution also give rise to behavioural abnormalities. Normal schooling behaviour, for instance, can be disrupted by a pollutant. The learning ability of fish can be affected by very low concentrations of chlorinated hydrocarbons. [33] This may impair their ability to return to their home stream, especially if they are subjected to these concentrations in the juvenile stage during the imprinting period.

Low levels of pollution can also affect the chemo-receptors of fish which also impairs their ability to find their home stream, to locate food and avoid predators. A fish's equilibrium can also be affected by low levels of mercury. [34] [35] [36]

Sockeye smolts infected by parasites succumb to lower concentrations of metals than uninfected fish and, in general, fish exposed to low level pollution either become infected by a disease more readily than unexposed fish, or may break out with a disease that previously existed only in a latent form.

What is important is that in general, an organism whose health has been impaired by low levels of different pollutants, need not display any clinical symptoms until such time as the cumulative damage makes it vulnerable to a particular insult, which in normal conditions it could simply have taken in its stride. This means that by the time clinical symptoms do appear, the organism is already so badly damaged that it may no longer be viable.

It is easy to see why this must be so once one understands the physiology of basic biological functions. To quote Anthony Tucker,

"Functions such as seeing or the co-ordination of movements or, indeed, any activity, are not the outcome of the activity of single neural cells. All are the outcome of processes which involve thousands and probably millions of interconnected cells. Such systems have what electronic engineers are prone to call a high level of redundancy. That means that many pathways are not strictly necessary for the function to be carried out efficiently, but simply duplicate or triplicate other pathways in case some kind of blockage or breakdown occurs. [37]

This consideration needs weighing very carefully when considering the effects of organic mercury, lead or the many organochlorine and other pesticides which, like DDT, can incapacitate neural systems, for it means that by the time clinical symptoms of nervous disorder appear, such as lack of co-ordination or loss of vision, then enormous damage has already been done to the structure of the brain.

It also means that quite extensive damage can be done without any clinical symptoms ever becoming detectable. This, in relation to heavy metals, is a terrifying prospect.

Dr S. G. Rainsford of the medical branch of the British Factory Inspectorate, comes to a similar conclusion when reporting on a 6-year survey of lead workers carried out by his organisation.

"The most disturbing factor is that the worker can be severely poisoned by lead without either having symptoms or showing clinical signs of plumbism. Probably the commonest early symptoms are abdominal discomfort, dyspepsia, loss of appetite and general aches and pains, the latter frequently being described as rheumatism, fibrositis, etc." [38]

Another very significant study also cited by Anthony Tucker was carried out in Edinburgh in 1965. It revealed that symptoms of lead poisoning tended, in the course of medical practice, to be treated as a normal occurrence without there being any attempt to seek their cause. Needless to say, the health of those affected had been impaired and the chances of their succumbing to a serious disease, which they could otherwise have easily survived, had correspondingly increased.

The same principle is well illustrated by the well-publicised incident in which 50,000 - 100,000 sea birds, mainly guillemots, died from no apparent cause in the Irish Sea in the autumn of 1969. Largely because of the popular outcry, the incident was carefully investigated by a team of scientists headed by Dr Martin Holdgate, head of the government's Central Unit on Environmental Pollution.

What is particularly interesting is that no single factor could be incriminated. During the summer of that year there were heavy storms which may have made it difficult for the birds to feed themselves. Indeed all the dead birds seem to have suffered, in different degrees, from starvation. Their bodies also were found to contain unusually high levels of PCBs. These tend to accumulate in the body fat, just as does DDT, to which these substances are closely related.

It seems probable therefore, that, being short of food, their surplus fat was mobilised which led to the transfer of these poisons into the blood stream. This could quite conceivably have resulted in their death. But further examination showed that their bodies also contained relatively high levels of all sorts of toxic elements such as cadmium, selenium, mercury, lead, etc. which could also have contributed to their demise.

Anthony Tucker points to the implications of this disaster:

"The ragged wreckage of dead birds speaks for itself. Like similar wildlife catastrophes in North America and elsewhere, this disaster contains a grave message, whose importance cannot be overestimated. It is that the thresholds of environmental calamities are obscure; that levels of contamination are already past the point at which they can amplify many times - perhaps hundreds of times - the fatal effects of purely natural stresses; that it is impossible to predict where disasters will strike and often impossible to define causes after they have happened; and that there is little to be gained from niggling arguments about particular effects of individual components of contamination. The burdens of toxic metals as a whole, and of organochlorines, have already degraded the entire context of the lifesystem." [39]

In the meantime, judging from reports in the Marine Pollution Bulletin, the contamination of sea birds, and hence of the marine environment itself, around these islands, continues to increase. A 1973 study on a representative series of marine and estuarine birds revealed that they were all grossly contaminated with mercury.

Levels in their liver ranged from 0.7 ppm to 122 ppm in the case of a redbreasted merganser. [40] We can only understand the full horror of these revelations if we realise how many other equally toxic pollutants are likely to be lodged in the livers of these birds - pollutants which our scientists have not yet been engaged to look for and measure.

What is happening to our sea birds is almost certainly also happening to us. A population living in a hideously contaminated environment such as ours, must be a sickly one, which in fact it is. It is not surprising that there are hundreds of thousands of people waiting for beds in our hospitals and that the annual cost of our National Health Service should now be nearly £19 billion (1987) and increasing, much faster than the GNP. Indeed, if current trends are allowed to continue, the whole of our GNP in a few decades from now, will have to be spent on trying to reduce the toll of human disease.

In the meantime the tendency in diagnosing a disease is still to look unsuccessfully for single cause-and-effect relationships. It is assumed that if a person is ill there is a single reason for it. The possibility that the illness might be due to the combined effect of hundreds and thousands if not millions of different 'causes,' all of which have contributed to reducing his or her resistance to disease, is not even considered.

Synergistic effects

It is not just the effects of so many pollutants that we must take into account, but the possible synergistic effects between specific pollutants which, as the SCEP Report states, are "more often present than not". [41]

Thus Professor Irving Selikoff has shown that asbestos insulation workers who smoke cigarettes have an 8 times greater risk of contracting lung cancer than other smokers simply by virtue of their exposure to asbestos, but a 92 times greater risk than non-smokers because of the very powerful synergic effect between exposure to asbestos fibres and tobacco smoke. [42]

The addition of mercury to sea water appears to inhibit the growth of 21 different strains of bacteria involved in the degradation of oil in sea water. [43]

The presence of a small amount of DDT, equivalent to that found in humans, greatly increases the liver damage produced by small amounts of carbon tetrachloride. [44] The toxic effects of this solvent are also increased 100-fold by the addition of the common drug phenobarbital.

The addition of oil to water substantially increases the damage done by DDT, PCBs and other such poisons that are not very soluble in water but that are very soluble - perhaps as much as 10,000 times more so - in oil. [45]

The addition of the commonly used dispersant BP. 1100 x Finasol OSR 2 to oil during a spill, increases its toxicity to herring larvae by 50 - 100 times, quite apart from seriously increasing the period during which it is acutely toxic. [46]

The use of chlorine as a disinfectant in our drinking water may have a whole range of synergistic effects with chemicals that are often present in it. Thus when associated with benzene it can, in the presence of ultra-violet light, give rise to hexachlorocyclohexane (HCH) - a particularly toxic insecticide. [47]

Epstein points out that modem toxicology does not take into account additive or synergic effects. [48] Nor are they taken into account, as Schubert points out, in setting the acceptable levels for exposure to mutagens. [49] For instance, the International Commission for Radiological Protection defines an acceptable risk as one which would involve the doubling of the spontaneous rate of occurrence of genetic damage. But if one takes into account the possible synergistic effects of each mutagen, then such a criteria seems absurd.

As Professor Bryn Bridges notes

"What is a suitable recommendation for one mutagen (i.e. radiation) will not suffice when each of a number of mutagens is considered. It has been estimated that about a 1,000 to 1,500 new chemicals are introduced into the environment each year, of which no more than a minute fraction is tested for mutagenic activity. If a thousand mutagens were each allowed at population doses, which doubled the spontaneous rate, then the overall rate might go up a thousandfold, quite apart from any synergistic interaction which might occur." [50]

Of course, if minute doses of different pollutants are damaging, then one can only reduce the damage by limiting the number of pollutants released into our environment. Such a policy, of course, would not be consistent with the achievement of our present economic priorities.

Tumour promoters

It also appears that cancer can be induced by a single exposure to a very low level of a known carcinogen, one that would not normally cause cancer, when this happens to be combined with prolonged exposure to equally low levels of a substance that is not in itself carcinogenic. Such a substance is referred to as a tumour promoter. [51]

This principle may explain the induction of skin cancers and has also been shown to be relevant to explaining other cancers, including those of the lung, colon, bladder and liver. It tends to confirm the notion that carcinogenesis is a multi-step process. A single insult may not always be sufficient; others of a different sort being required before cancer develops.

Croton oil is said to be a promoter. It is a complex mixture of chemicals including esters of the plant alcohol phorbol. The ester referred to as TPA (12-0-tetradecanoylphorbol-13-acetate) is an especially effective promoter. It appears that the combination of an initiating carcinogen plus TPA, is at least ten times as effective in inducing tumours as the carcinogen alone.

Other suspected tumour promoters are phenobarbital and the artificial sweeteners saccharin and sodium cyclamate. Bile acid is meant to be a promoter which is supposed to explain, in part at least, the relationship between cancer and a high fat diet.

How the promoters act is not entirely clear. One effect may well be to interfere with the normal development of cells. This is shown to be the case with phorbol ester promoters by researchers at the Wistar Institute of Anatomy and Biology at the University of Pennsylvania. These promoters inhibit the differentiation of a variety of cells in culture. Once the cells become mature, they lose their capacity to divide but if their differentiation is inhibited, they remain in an immature state and continue to divide, perhaps in an uncontrolled way as do malignant cells.

If this is so, then the implications are dramatic. It means that in trying to determine whether a particular chemical is carcinogenic in the real world, we must not only look for synergic effects with other carcinogens but also with a host of other non-carcinogenic chemicals which could conceivably act as tumour promoters.

Decay products

To fix an acceptable level for any chemical would also require taking into account the nature and toxicity of the substances that, under different conditions, tend to be associated with it, which would include, as Epstein points out, its "chemical and metabolic derivatives; its pyrolytic and degradation products; and its contaminants and reactor products." [52]

Thus the thinning of the shells of bird eggs which has resulted in large-scale breeding failures and the near extinction of many species of birds at the top of the food-chain appears to be caused not by DDT as suspected but by its decay product DDD. It is also possible that under certain conditions, it degrades into PCBs which would make nonsense of calculations of acceptable levels of this substance in industrial effluents.

Cyclamates are not dangerous in themselves but because they decay into carcinogenic cyclohexylamine. NTA, which detergent manufacturers introduced to replace phosphate-based detergents, also breaks down into products with toxic properties.

Mercury, in its inorganic form, is largely insoluble in living tissue. Its half-life in most mammals, as Anthony Tucker points out, is only 6 days, which means that it is rapidly removed by the body's natural detoxification mechanisms. However under the action of bacteria in the water and in the soil, it breaks down into an organic compound whose half-life in the body is about 70 days. [53]

This means that the total body burden of someone ingesting 2 milligrammes of inorganic mercury would be no more than 20 milligrammes, however long the exposure. In the case of organic mercury the figure would be 200 milligrammes within a year, though death would intervene long before.

The same appears to be true of lead, which scientists have discovered to be very readily transformed into an organic form, which is very much more toxic than the inorganic variety. It is probably also true of plutonium. Dr Bowen has reported several times that in the marine organisms examined in his laboratory, he found that concentrations in living tissue were a hundred to several thousand times higher than in the surrounding water. [54]

Particularly important for those eating fish from the Irish Sea is that plutonium 241 can decay into americium 241. The latter is an alpha emitter - the former is not - and releases of it are thereby not included in the permissible levels of alpha emitters released into the sea from the Sellafield retreatment plant in Cumbria.

In 1969, the permissible releases were increased from 1800 curies to 6,000 curies per year and since then, according to Peter Bunyard, 40 times more plutonium 241 has been discharged from Sellafield than all the alpha emitting isotopes of plutonium put together. It may well be that

British Nuclear Fuels who operate Sellafield have succeeded in conning the public into being allowed to discharge more than seven times the quantities authorised, which are already scandalously high, as evidenced by the fact that plutonium, one of the most carcinogenic substances known, is now a general contaminant (though at the moment in small quantities) of fish life in the North Irish Sea." [55]

Once again we are faced with a consideration that unfortunately we cannot afford to take into account without compromising economic goals. The cost of examining the innumerable decay products of all the chemicals we have introduced into our environment would be incalculable, the consequences of banning the chemicals whose decay products proved to be harmful, economically inconceivable.

Toxic impurities

Toxic impurities also tend to be present in many chemicals, causing them to be very much more toxic than they would otherwise be. This is known to be the case with the organophosphate, Diazinon, used in homes and gardens for cockroach control. It contains an impurity called sulphotep, which is 30 - 100 times more toxic than Diazinon and is much more stable.

Its build-up in the environment is favoured by the fact that organophosphate pesticides tend to be applied at more frequent intervals than the more persistent chlorinated hydrocarbons that they have in some cases replaced, which must lead to a gradual building up of sulphoteps.

Delayed action

A further complication is that the effect of pollutants on biological organisms may take a very long time to show up. Thus 7 years after atomic bombs had been dropped on Hiroshima and Nagasaki, a high incidence of leukaemia began to be observed among the survivors. After a few years this began to fall off, and it was assumed that the worst was over. However, 15 years or so later, an unusually high rate of cancer started appearing among the survivors. This tended to confirm the now well established fact that tumours may appear a very long time after exposure to a carcinogen.

It has also now been found that some cancers only appear a generation later. A rare form of vaginal cancer, for instance, has been observed among women whose mothers were administered the hormone diethystilboestrol (DES) during pregnancy. Carcinogens are also known to cross the placenta and affect the foetus causing cancer in later life.

The delayed effects of pollutants in increasing the vulnerability of ecosystems to population explosions, in reducing the resistance of populations to diseases and also in seriously changing the composition of the atmosphere and the stratosphere, may take a very long time to detect. As the OECD Environmental Directorate reports, for instance,

"because of the long time-lag between release of fluorocarbons to the atmosphere and their migration to, and eventual removal from, the stratosphere, their full impact may not be apparent for a decade or more." [56]

This may be an understatement since it may even take as long as a century for halocarbons to reach the stratosphere. [57] The trouble, as the Environmental Directorate points out, is that by that time it may be too late to avoid serious consequences for humans and their environment.

The delayed effect of carcinogens also renders useless epidemiological studies of carcinogenesis triggered off by substances that have not been in use for at least 20 - 25 years. Unfortunately, a large proportion of potential carcinogens, in particular synthetic organic chemicals, fall into this category, as do cyclamates.

The Committee of the National Cancer Institute looking into the safety of this substance, concluded that no epidemiological data were available since bladder cancers had a latency period of 20 years or more and "cyclamates had not been on the market long enough for cancers to show up." [58] Yet we are still constantly being assured of the safety of chemicals on the basis of such tests.

As Wurster pointed out, the studies conducted by Hayes and his colleagues and those conducted in the Shell Laboratories which claimed to establish the innocuousness of DDT, could not have done so for a variety of reasons, one of which was that the periods of exposure were too short to detect carcinogenicity. [59]

Yet the National Cancer Institute's report on the effects of fluoridation of American water supplies states that

"no significant excess mortality from cancer could be detected up to fifteen years after fluoridation in areas where ninety-five percent of the population had been abruptly and continuously exposed."

This is supposed to justify the dubious thesis that fluoridation does not increase the cancer rate. [60]

The identification of chemicals

The problem of establishing levels for different environmental pollutants is further complicated by the fact that we have identified no more than a fraction of them.

As Professor René Dubos pointed out, there are probably hundreds of unidentified pollutants in car exhaust alone. He estimates that we have identified less than 30 percent of those contained in the air we breathe in modern cities, but

"recent experiments have shown that newborn animals exposed to these undefined contaminants may show disastrous consequences when they become adults." [61]

The plume of vapour from the Seveso Plant, as Anthony Tucker notes, probably contained

"a cocktail of great complexity whose constituents were not only biologically potent at concentrations close to the limits of detection. . . and 'so subtly interwoven chemically' as, for all practical purposes, to defy identification." [62]

An EPA study of America's drinking water reveals that

"there may be a myriad of organic chemicals, not yet isolated and identified, such as the pesticides that could be present in these water supplies, which are carcinogenic, teratogenic or mutagenic." [63]

In the UK, a study by Fielding and Packham comes to the conclusion that it is, to all practical purposes, impossible to identify the organic pollutants in our drinking water. Even though a litre of urban drinking water may not contain more than twenty milligrams of organic constituents, this small amount of material

"is a very complex mixture containing hundreds of different compounds some of natural and some of synthetic origin. Its analysis is difficult and even the most advanced and elitic technology cannot yet identify more than ten to twenty percent of the organic material present." [64]

The inter-agency Task Force on Inadvertent Modifications of the Stratosphere (IMOS) has pointed out the difficulty in identifying stratospheric pollutants. It warns,

"The additive effect from several substances might become significant in the future, even if the effect from any individual substances is relatively small."

It also warns that there may well be materials yet to be invented or discovered that are serious candidates for concern. [65]

Different levels at different times

The problem of establishing acceptable levels and monitoring them satisfactorily is further complicated by the fact that levels observable in an organism or in an ecosystem are constantly changing.

Thus it has been found that American oysters accumulate twice as much cadmium from the surrounding water during the months of July and August as during the winter and the spring. The reason appears to be that the higher water temperature during the summer increases the oysters' metabolic rate. This causes them to pass more of the surrounding water over their gills in a given time and thereby to be exposed to more cadmium. [66]

The DDT content of barracuda in US waters which tends to be high most of the year, falls by about 75 percent during the spawning season. It coincides with the loss of fat in which the DDT is stored and is somehow returned to the environment, but just how nobody seems to know. [67]

Unusual climatic conditions can also lead to big variations in pollution levels. The 1976 drought in Britain, by drastically reducing the flow of water in British rivers, radically reduced their capacity to dilute pollutants. This could not but affect fish life and also reduce the quality of available drinking water.

Because of the 1976 drought too, ozone levels in central London regularly rose above 20 parts per 100 million. Worse still, in early July, for 8 consecutive hours on 5 consecutive days, ozone levels averaged more than 10 parts per 100 million (the industrial safety level) with peaks of 25 parts per 100 million - which was well above previous peaks of 16 pphm at Harwell. [68]

The ozone concentration of the stratosphere is also changing very regularly.

"There are large natural variations of ozone on a scale of days to many years, and of a complexity which cannot be readily incorporated into current predictive models." The natural variations are in fact so large that it has been "estimated that a five to ten percent decrease in ozone, persisting and measured for several years, would be needed before a change could be attributed to man's activities with any statistical reliability." [69]

Levels are also constantly changing simply because of people's polluting habits. If a chemical company cleans out vats containing some noxious chemical on a particular day, levels of the pollutant, which may have been very low the day before, will clearly substantially increase, at least temporarily.

Dr J. Sontheimer, a chemist working on the pollution of the Rhine, notes how levels of different pollutants vary from day to day.

"There is no way of foreseeing what will be floating in the river tomorrow ... a cleaning process that works well one day, works badly the next." [70]

Under these conditions the value of individual measurements is negligible. To be significant, they would have to be carried out over a long period - which, among other things, would present insuperable logistical and financial problems.

Accidents

Establishing acceptable levels for different pollutants is in any case fairly fruitless, in view of the increasing vulnerability of our society to large-scale technological accidents, that are already leading to the exposure of whole populations to very high levels of dangerous pollutants.

Government and industry invariably assure us that the odds against a serious accident occurring in a particular industrial installation are massive - one in a million, for instance, against this occurring at a nuclear power station. However the odds against two jumbo jets colliding on a runway appeared to be equally negligible until it actually occurred at Las Palmas.

So were the odds against any of the large-scale pollution disasters of the last few years: the massive leakage of radioactive waste at Hansford; the Dioxin disaster at Seveso; the arsenic trioxide disaster at Manfredonia; the PBB one in Michigan; as well as the Chernobyl disaster (which, of course, has occurred since this text was originally written). The experts told us they could, in effect, never happen - but they all did and the damage they have done has been on an intolerable scale.

Murphy's law

We must realise that it is impossible to design, build and operate a technological device that cannot go wrong. This is a principle known to engineers as 'Murphy's Law'. It states, "if it can go wrong, it will go wrong."

One cannot ever design a typewriter, a bicycle or even a motor car, that is not subject to breakdowns. This may not matter too much, for any accidents that can occur to such devices are on a relatively small scale and will affect but a small number of people. This is not so, however, in the case of accidents occurring at nuclear and modern chemical plants.

Apart from technological breakdowns one must also consider the human element. People simply cannot be counted upon to deal with routine matters, day in day out, with the care and attention normally displayed in emergency situations only; which means that accidents caused partly at least, by human error, are, in the long run, inevitable.

Consider the case of the famous accident at the Browns Ferry Nuclear Power Plant in Alabama on 2 March 1975. Mr Gregory Minor, the manager of advanced control and instrumentation, stated himself that the safety systems in operation "went far beyond the normal levels of reliability."

What happened was that fire destroyed the safety equipment. This sort of mishap was indeed extremely unlikely but could not be ruled out. "You can't expect these things to run flawlessly for forty years with so many people involved", said Mr Minor. [71]

With the rapid breakdown of our society and an ever more reduced sense of responsibility, the problem is likely to get worse rather than better. It is interesting that a chief engineer at Sellafield should be the one to make this point:

"I do not think the country can operate with an acceptable standard of safety an extremely dangerous plant like Windscale under current standards of respect for law, national and personal morals and discipline in social and industrial affairs. To maintain safety in such a plant calls for standards of personal dedication, sense of responsibility and discipline which do not generally exist in the permissive society. This has been demonstrated by the fact that the Windscale workforce was prepared to hazard public safety in pursuit of a minor financial objective. (It went on strike) Might not a later generation occupy the plant and threaten sabotage if their demands are not met?" [72]

The nuclear installation at Sellafield has already been the scene of many accidents, one of which in 1957 was very serious, leading to the escape of considerable quantities of radioactive gases into the environment.

Dr Wakstein made a study of the lesser ones from the limited amount of material made available by British Nuclear Fuels Ltd (BNFL). He could only find reference to 28 accidents. However, prompted by the then Minister of Energy, Tony Benn, BNFL later produced a list of 177, most of them additional and as Wakstein points out "not hitherto disclosed to the public". [73]

If the overlap in the second list is eliminated, it appears that there was a total of 194 accidents and 'incidents' between 1950 and mid 1977 and more have occurred since. Eleven involve fires or explosions, seven have reference to criticality and about 45 involve releases of plutonium; the average rate is 7 or 8 a year and the number is increasing.

BNFL refuse to regard them as accidents. They are referred to instead as "incidents" and on each occasion the public is assured that no harm can possibly come to it. This is a totally dishonest assurance, since the pollution released cannot be permanently isolated from the biosphere and must somehow and sometime find its way into biological systems, thereby causing biological damage including mutations and cancers.

What must be considered is the sheer number of these incidents. Also imagine what it would be like in this country if we went ahead with Mrs Thatcher's programme and sought to become dependent on nuclear power stations for 50 to 80 percent of our energy requirements, which would mean covering this tiny island with a network of several hundred nuclear power stations, together with their allied installations, etc. We must also imagine what it would be like if we then went ahead with our breeder-reactor programme.

Sir John Hill, in his time the most fervent advocate of nuclear power in Britain, admitted that

"if something went wrong with a fast breeder reactor it could explode. No plant of any description can be made to deliver over a million horsepower without the chances of an explosion if something goes wrong." [74]

Dr Farmer, Safety Advisor to the UK Atomic Energy Authority, has admitted that if this occurred there could be as many as a million casualties.

Dr John Edsall, the Nobel Laureate, also describes what the dangers from accidents might be if the US went ahead with its breeder-reactor programme:

"The hazards of the present reactors will be multiplied many fold in the breeder; an explosion in a fast breeder could make thousands of square miles uninhabitable for many years, and could endanger the lives and health of millions of people." [75]

The epidemiological approach

It may be argued that we can make up for the difficulty in establishing acceptable levels of a particular chemical by concentrating more on epidemiological studies. These can obviously help, but too much cannot be expected of them in view of the fact that people living in modern industrial conurbations, are exposed to a wide range of different pollutants at levels, which, in a given area at least, may not be too dissimilar and that, in such conditions, the identification of a dangerous chemical is only likely under exceptional conditions.

Thus, as Epstein points out, the carcinogenic effect of asbestos was determined largely because of the very rare form of lung cancer (mesothelioma) associated with it. The carcinogenic effect of diethystilboestrol (DES) was also only discovered because of the very rare form of cancer of the vagina (adenocarcinoma) it induced in the daughters of women exposed to it during pregnancy - and even then it would probably not have been discovered, if a lift had not broken down in Boston, enabling the paths of a gynaecologist and a pathologist to cross for a sufficiently long time for them to exchange relevant experiences. [76] The teratogenicity of thalidomide was recognised only by the bizarre deformities it produced. As Epstein writes,

"In all likelihood thalidomide would still be in use as a safe drug, had it produced relatively common anomalies, such as cleft palate or strial septal defects."

Epstein further points out that no known major human teratogens such as X-rays, German measles, mercury or thalidomide "have been identified by prospective epidemiological approaches, even in industrialised countries with good medical facilities." [77]

A further problem is that adverse reactions to drugs are rarely reported. Thus, though there were recurring complaints about the side effects of the drug practolol which ICI has now taken off the market for causing sclerosing peritonitis, these tended to be ignored by prescribers even though they were often serious (damage to sight, hearing, or the gastro-intestinal tract). [78]

From animal to human

Even were we to overcome all these problems we would still be faced with a further one. For obvious reasons, it is very difficult to establish permissible levels on the basis of experiments with humans. Animals of some sort must be used. Unfortunately, however, tests carried out with laboratory animals only provide a vague indication of how they will affect humans. Epstein points out for instance, that

"Meclozine and antihistamine, used to treat morning sickness, is teratogenic to the rat but apparently not so to humans. The opposite is the case with thalidomide, to which humans appear to be sixty times more sensitive than mice, a hundred times more than rats, two hundred times more than dogs and seven hundred times more than hamsters." [79]

On the other hand, because of the basic similarity of all forms of life at a molecular level, it seems reasonable to consider that chemicals which are carcinogenic to one form of life tend to be carcinogenic to others as well.

The number of pollutants

The problem is further aggravated by the literally incalculable number of chemical substances we have introduced into our environment. To begin with, there are those that have been introduced on purpose - and are used in commercial products of different sorts. Their number is increasing very rapidly every year.

According to Blodgett, 400 active chemicals were used in this way in 1965, formulated in over 60,000 registered products of which some 35,000 were for agricultural application. By 1973, however, the number of registered products was 33,000 incorporating some 900 different chemicals, although twenty substances amounted to 25 percent of the US production. [80]

As Blodgett points out, very few of these have yet been adequately tested. In the meantime, an estimated 500 to 2,000 new chemicals enter large-scale commercial use each year. Of these, the NCI subjects only 150 to long-term rodent feeding tests, each of which in 1976 was said to cost $100,000. [81]

But we must also take into account the far more numerous by-products generated during the production of these chemicals. Together, according to the United Nations Environment Programme (UNEP), they amount to several millions and the number of further substances that combinations of these could yield is so great as to defy the imagination. [82]

Dr Saffiotti of the National Cancer Institute estimates that two million at least are known. Of these, however terrifying as it may seem, only 3,000 have been adequately tested for carcinogenic properties, while 1,000 have shown some signs of being carcinogenic. [83]

But what do we mean by adequate testing? The NCI tests are carried out on an average of 800 animals. But can such tests really provide the information we require? Undoubtedly not. If we take into account the immense number of potentially harmful chemicals to which industrial people are exposed and their additive and possible synergistic effects, we must test for minute biological effects which, needless to say, renders the problem even more intractable. As Epstein writes,

"Assume that man is as sensitive to a particular carcinogen or teratogen as the rat or mouse. Assume further that this particular agent will produce cancer or a birth defect in one out of 10,000 humans exposed; then the chances of detecting this in a group of fifty rats or mice, tested at ambient human exposure levels, are very low. Indeed, samples of 10,000 rats or mice would be required to yield one cancer or teratogenic event, over and above any spontaneous occurrences; for statistical significance perhaps 30,000 rodents would be needed." [84]

Megamouse experiments

Saffiotti considers that to test potential carcinogens at very low levels similar to those at which human populations may be exposed, through residues in food for instance and in order to detect a low incidence of tumours, about 100,000 mice would be required per experiment. Each experiment would cost about $15 million (1979) and to carry out a significant number of them would

"block the nation's resources for long term bio-assays for years to come and actually prevent the use of such resources for the detection of potent carcinogenic hazards from yet untested environmental chemicals." [85]

Even then, the results, for a number of reasons, would be highly contestable. To begin with such an approach assumes that there is a threshold dose at which a carcinogen is no longer effective and, as we have seen, and also as Saffiotti points out, "there is presently no significant basis for assuming that such a threshold would appear."

Secondly, these studies would, in any case, have to be confirmed by other tests carried out in different conditions such as variations in diet, variation in the vehicles used, in the age of the animals, in their sex, etc. Each of these tests would then imply further megamouse experiments.

What is more, they would clearly have to be tested in combination with countless other chemicals, with which they may have additive or synergic effects. They would also have to be tested over that period during which delayed symptoms might be expected to occur, while to test for mutations would mean carrying out such tests on animals for many generations.

The ecological approach

The fact is that the problem cannot be solved in terms of what passes today as 'scientific method'. This is now admitted by a growing number of scientists who have seriously considered all the factors involved. Professor Alvin Weinberg is among them. He considers that a new 'trans-scientific' methodology is required for this purpose. On this subject it is worth quoting him in full.

"[The question] 'What is the effect on human health of very low levels of physical insult?' can be stated in scientific terms; it can, so to speak, be asked of science, yet it cannot be answered by science. I have ... proposed the name trans-scientific for such questions ... Let me use as an example of a trans-scientific question the problem of low-level radiation dose ... One may well ask, assuming the dose-response curve to be linear down to zero dose, how large an experiment would be required to demonstrate empirically that 170 millirems ... would increase the mutation rate by the 0.5 predicted by the linear dose-response theory. The answer is that around 8 ^ 10 mice would be required to demonstrate a 0.5 percent level at the 95 percent confidence level. So large an experiment is beyond practical comprehension. The original question as stated is therefore, in my terminology, trans-scientific. Where low level effects are concerned, there will always be a trans-scientific residue." [86]

It follows that it is not by making millions of deceptively precise measurements that we can understand how pollution is affecting our environment, such an enterprise being, among other things, logistically impossible. It is the effect of pollution taken as a whole on living systems taken as a whole that we must consider.

This is the conclusion of Caroll Wilson and his colleagues' 1969 Study of Critical Environmental Problems (SCEP): Man's Impact on the Global Environment, which is still by far the best study on global pollution problems. Its authors considered that our "total pollution burden may be impossible to determine except by direct observation of its overall effects on ecosystems." This is also Schubert's conclusion:

"It has become apparent that an overall approach is necessary if society is to control and minimise genetic and toxicological risks to the population. It is unproductive and self-defeating to repeatedly deal with an individual chemical on an emergency basis simply because it happens to make the newspaper headlines. Repetition of such piecemeal consideration eventually distracts the public and government from the general problem of how to deal with the myriad of chemicals to which the population is exposed." [87]

Not only would this be logistically feasible but it would also provide information on which we could act. At the moment, we cannot take action to ban specific groups of pollutants suspected of being carcinogenic (phenoxy herbicides, organochlorines, etc.) At best, we can incriminate one or two individual chemicals which are then treated as scapegoats for the rest.

Nor can we take action to prevent the release of poisons into our environment as a whole, but only into certain parts of it, where the damage has been carefully documented by innumerable measurements, leaving us free to export the pollution to other areas where the effect of the pollutant is, and always will be, less well documented.

On the basis of today's criteria, it is possible for manufacturers to make out a case for the innocence of each one of the four million or so pollutants that they generate directly or indirectly, as a by-product of their activities, a case that can rarely be refuted on the basis of currently accepted scientific methodology.

Yet we know that between them, these pollutants are, among other things, causing the deaths of several million people a year from cancer. Though we cannot prove that individual pollutants are contributing to this damage, their guilt when seen as a group, is incontestable. This principle not only applies to the study of how pollution affects natural systems but to the study of natural systems themselves, indeed to that of the biosphere as a whole.

Professors Jay Forrester, Denis Meadows and others have pointed out how the reductionist methodology of modern science does not enable one to understand the behaviour of natural systems. It must be remembered that natural systems are above all organisations, which means that they are more than the sum of their parts, their identity and main characteristics being derived very largely from the way in which these parts are organised.

This means that they cannot be understood simply by examining and measuring these parts individually and in isolation from each other, which is basically what our scientists are still trying to do, but only in the light of a general model, reflecting not only their relationship to their own component parts but also to the larger systems of which they in turn are part. Such a model need not be quantitative. What we are interested in are the generalities not the particularities; the theoretical principles involved not just a mass of undigested quantitative data.

Also it is not by measurement that we can determine what are these principles. In the scientific world of today, measurement has largely replaced thought. Thinking, in fact, has gone out of fashion. If we want to understand how the world works and how we are to adapt to it we must learn to think again and not with the aid of those clumsy machines called computers but with our brains which are infinitely more sophisticated pieces of equipment.

Let us then try to consider how we could examine pollution in its total biospheric context.

Theorectical considerations

It took several billion years of evolution for the biosphere or world of living things, of which we are an integral part, to take on the shape in which industrial society found it and thereby provide an ideal habitat for humans and the myriads of other forms of life that compose it. During the course of this evolution, as Commoner puts it,

"The chemical, physical and biological properties of the earth's surface gradually achieved a state of dynamic equilibrium, characterised by processes which link together the living and non-living constituents of the environment. Thus were formed the great elementary cycles which govern the movement of carbon, oxygen and nitrogen in the environment, each cycle being elaborately branched to form an intricate fabric of ecological interactions. In this dynamic balance, the chemical capabilities of living things are crucial, for they provide the driving force for the ecological cycles; it is the chemistry of photosynthesis in green plants, for example, which converts the sun's energy to food, fibre and fuel. [88]

The biosphere can function as a self-regulating natural system and maintain its basic structure on which the very survival of its living components depend, only if the critical interrelationships between all its components - at all levels of organization, including that of the atom or the molecule - are maintained. As Commoner further points out

"... the chemical processes which are mediated by the biochemical system represent an exceedingly small fraction of the reactions that are possible among the chemical constituents of living cells. This principle explains the frequency with which synthetic substances that do not occur in natural biological systems ... turn out to be toxic."

Commoner illustrates this principle thus:

1. Of the approximately one hundred chemical elements which occur in the materials of the earth's surface, less than twenty appear to participate in biochemical processes, although some of those which are excluded, such as mercury or lead, can in fact react quite readily with natural constituents.
2. Although oxygen and nitrogen atoms are common in the organic compounds found in living systems, biochemical constituents which include chemical groupings in which nitrogen and oxygen atoms are linked to each other are very rare.
3. Although the numerous organic compounds which occur in biochemical systems are readily chlorinated by appropriate artificial reactions, and the chloride ion is quite common in these systems, chlorinated derivatives are extremely rare in natural biochemical systems.

It is no coincidence that these chemicals are not found in living tissues. There is good reason for it. The organisation that is the biosphere has been able to evolve at the expense of eliminating possible reactions between these substances and living things. If any living systems once included them, then they have been eliminated by natural selection.

The consistent absence of a chemical constituent from natural biological systems is an extraordinarily meaningful fact. It can be regarded as prima facie evidence that, with a considerable probability, the substance may be incompatible with the successful operation of the elaborately evolved, exceedingly complex network of reactions which constitutes the biochemical systems of living things.

Furthermore, such theoretical considerations can be confirmed empirically.

Thus mercury is one of those 80 elements not essential for living processes. There is at least one good reason for this. Biochemical systems have evolved a system of enzymatic catalysis in which sulphur-containing groups play a crucial role. These react with mercury introduced into a living system and enzymes are inactivated, often with fatal results.

There is also a good reason why synthetic nitroso compounds in which nitrogen and oxygen atoms are linked do not occur either in living tissue. They appear to interfere with the reactions involved in the orderly development of cells, and give rise to cancer and mutations.

There is also a good reason why synthetic organochlorine compounds such as DDT and PCBs are excluded from living tissue. They are often very toxic or produce long-term damage such as cancer.

How does a living system succeed in excluding unwanted chemicals? The answer is that either these chemicals are not present in its environment in that form which would permit them to interfere with it, or the system develops subtle homeostatic mechanisms for maintaining low levels within it, even if the levels outside are higher.

These mechanisms, however, have developed via the evolutionary process - hence very slowly. They can only deal with chemicals found in that form and at that level to which the system was exposed during its evolutionary experience. In general the more the environment changes as a result of human activities, the less does it resemble that in which we evolved, and the less efficiently can our normal behavioural mechanisms enable us to adapt to it.

Thus, while the human liver is capable of detoxifying those chemicals that it has learnt to detoxify over millions of years of human evolution, it is incapable of detoxifying chemicals to which it has not been exposed during this period.

It is these considerations which led Professor Stephen Boyden of the Australian National University to formulate his principle of phylogenetic maladjustment. [89] He pointed out that since the evolutionary process is adaptive, it must be when subjected to that environment with which we have co-evolved that our biological needs are best satisfied.

This means that any modification of our environment causing it to divert from that to which we have been adapted by our evolution must lead to phylogenetic or evolutionary maladjustments and the greater this diversion the greater these maladjustments must be.

Banning pollutants

From the preceding analysis it should be clear that to avoid the rapid deterioration of the biosphere and the corresponding reduction in its capacity to support complex forms of life such as humans, there is no alternative but to reduce very considerably our environment's total pollution-load.

This cannot be done by examining individual pollutants by the reductionist method in controlled laboratory conditions, but only on the basis of a model that takes into account both theoretical and empirical factors, in terms of which the probability of the harmfulness of different chemicals can alone be established.

The degree of probability required must vary with the extent of the damage that a specific pollutant is suspected of causing. For instance, if it could be implicated in causing cancer or mutations or in possible climatic changes, then clearly, the slightest possibility of its guilt must be regarded as sufficient to warrant its removal from the market.

The chemicals that must first be withdrawn are largely those which have been introduced in the last 30 years - during which time, as Commoner has pointed out so convincingly, pollution levels have escalated in the US by between 200 and 1,000 percent - totally out of proportion to the economic growth registered during this period and even more so with any possible benefits we might have derived from their use. [90]

Foremost among these chemicals are the synthetic organics which must include the synthetic nitroso and organochlorine compounds mentioned by Commoner. There are some 9,000 of them, mainly used as plasticisers, aerosol propellants, refrigerants, pesticides and herbicides. According to Epstein

"Very few, if any of these compounds are without toxic effects, either because of their own chemical properties, or because of chemicals discharged to the environment during their manufacture, or because of breakdown products, or because of some potentiating, synergistic effect when they come into contact with other chemicals." [91]

Yet as Saffiotti points out,

"only a small proportion of these substances are exhaustively tested against the possible hazards contingent upon wide dispersion in the environment." [92]

These are only the most obvious ones, the list of all the toxic chemicals that we are releasing, in an almost uncontrolled manner, into our environment would be a much longer one; it would include the several thousand chemicals we add to our food during processing, few of which, according to Ross Hume Hall, "have received more than a cursory examination", or have been rigorously tested for their ability to cause "birth defects, heart attacks, cancer and behavioural abnormalities". [93]

It would include nitrites, used extensively as food preservatives, and nitrogen fertilisers, whose massive use is leading to an equally massive increase in the nitrate content of our drinking water. But banning the use of such substances would not be sufficient. Drastic reductions would be required in emissions of SO2, NOx and CO2 to the atmosphere.

It is doubtful if pollution levels in our society could be reduced by any other means than by deliberately reducing the level of our industrial activities. This would mean giving up the goal of 'material progress' and setting out - as Robert Prescott Allen and I proposed in A Blueprint for Survival - to create a totally different non-industrial society, one in which economic and political activities were carried out on a very much smaller scale.

Will there be any real attempt to control pollution

On the basis of past experience we know that, unless the Green Party were to form a government, such a programme would never be adopted. Things are done in our industrial society to satisfy three sets of requirements; those of our industrialists who want higher profits; those of our trade unionists who want more jobs at an ever higher rate of pay; and those of our politicians who want more votes. Profits, jobs and votes, are seen as best obtained by maximising economic activities and hence pollution.

We can thereby predict that the acceptable levels for different pollutants will remain as high as public opinion will allow polluters to keep them; that dangerous substances will not be banned unless they give rise to immediate visible large-scale catastrophes such as those which occurred at Minamata, at Seveso and (since this chapter was originally written) at Chernobyl; and even then they will probably only be banned locally and for a short period. The public's memory is notoriously short.

To justify its inaction, our government will make use of every subterfuge to con the public into believing that pollution is under control. Thus,

• it will persuade successive committees of learned experts to fix unduly high permissible levels for the different pollutants in our environment;
• measurements will continue to be conducted and interpreted in such a way as to allay public fears;
• additive and synergistic effects and the effect of decay products and impurities will continue to be disregarded;
• the accent will remain on short-term toxicological effects, while long-term carcinogenic and mutagenic effects will continue to be played down;
• the absence of hard 'scientific evidence' to prove the harmfulness of particular chemicals, will remain an obvious excuse for inaction - and as little money as possible will be spent on obtaining this evidence;
• lack of funds and the adverse effect on our standard of living of spending too much money on pollution controls will be another excuse;
• when action is taken it will be, as today, largely for cosmetic purposes.

"The government is more likely to be concerned with ameliorating the feelings of the public, of alleviating those factors that are visible and are the source of public controversy. For instance, when requests arise for cleaning stacks, industry may remove the steam which is visible, but disregard the more dangerous sulphur dioxide, which is invisible but much more difficult to remove from the exhaust." [94]

Just as our government has done so far in the UK. When our government is forced by public opinion to pass legislation designed to prevent further environmental contamination, one can predict in advance that such legislation will either be so emasculated that it will have little effect or else that it will never be implemented as has largely been the case with the 1974 Control of Pollution Act.

What of the future?

For all these reasons, one can assume that the vast bulk of the pollution generated by our industrial activities will find its way into our environment, which means that total pollution emissions to the environment will, to all intents and purposes, reflect closely the level of industrial activity.

This conclusion is implicit in most of the serious forecasts of pollution trends in Europe. The Economic Commission for Europe points out, for instance, that in spite of all measures taken to control the release of waste products of all sorts into the European environment, it is continuing to increase at a rate of about 5 percent per annum, while the quantities of inorganic waste released into the environment worldwide will continue to double every 10 - 12 years. [95]

In another, little publicised, OECD report it is admitted that the OECD area is rapidly reaching the point where it must choose between industrial expansion and clean air. The report predicted that emissions of nitrogen oxides and sulphur dioxide from the burning of fossil fuels would go on increasing, unless there was a reduction in fuel consumption and by implication of economic activity. [96]

Already, in one year, it appears the waste the European community has released into the environment includes 90 million tonnes of household refuse, 115 million tonnes of industrial waste, 950 million tonnes of agricultural waste, 200 million tonnes of sewage sludge and 150 million tonnes of waste from extractive industries.

The physical problem of disposing of such massive quantities of waste products is in itself a major one and the danger to public health is already, the Commission admits, serious. Yet by the end of the 20th century, if economic activity continues at the present rate, the quantities will have quadrupled - with wastes accumulating on the land, in rivers and waterways and in the atmosphere and often too, in biological organisms including human ones with inevitable detrimental effects on health.

Pollution by radioactive materials must also increase in the same way. Already, as Dr Spearing points out,

"merely the 'low level' releases to the environment, currently occurring, contain long-lived radio-isotopes which are being discharged at a rate exceeding the rate at which their radio-activity is decaying. In consequence, there is a gradual and insidious build-up of environmental radioactivity and there is a very real risk of irreversible contamination of our planet to a degree that will impose a severe burden of human suffering on future generations, quite possibly to the end of the story of human life on earth." [97]

As Sir Brian Flowers warns

"By the year 2000, a world nuclear power programme would have generated such large quantities of fission products (and actinides) that even if they were dispersed uniformly in the vast bulk of the oceans, the resulting concentration would be within one or two orders of magnitude of the maximum permissible concentration for drinking water. This would not be satisfactory because of the many food chains that would concentrate the radioisotopes and return them to man." [98]

With regard to marine pollution in general, one of the world's foremost oceanographers, Dr Edward Goldberg, writes

"Our concern is the haunting possibility that levels of a toxic material can rise so high that exposure of organisms to such materials in the open ocean, as well as in the coastal ocean, may result in widespread mortality or disease ... If these substances mix with the deep ocean, they will he transferred within a decade to zones below the mixed layer, where they may remain for thousands of years ... " [99]

He concludes that we may leave future generations "the legacy of a poisonous ocean".

Another consequence of the increased contamination of our planet must be the continued incidence of cancer. Already more than 25 percent (51 million) of the 200 million people living in the US will get cancer; 34 million will die of it. As Epstein points out

"most of the people dying today are over forty or fifty years old and were thereby brought up in that period that preceded the general contamination of our environment by most of the known carcinogens in general use today. We can thereby expect that when today's children reach the age of forty or fifty, the cancer rate will be very much higher." [100]

"Given today's environment we are living with a time-bomb that's going to explode in twenty or thirty years from now in the form of even more persons being stricken with cancer." [101]

Indeed at the rate at which the cancer rate is increasing today, it is only a matter of a few decades before this dreaded disease becomes generalised among the populations of industrial countries - a truly nightmarish prospect. It is now generalised among fish populations in highly polluted US East coast rivers.

However, perhaps one of the most dramatic consequences of present pollution trends must be changing climatic patterns. Professor Flohn at the Second International Conference on the Environmental Future, went so far as to state that "a global climatic catastrophe is unavoidable, if we continue to use energy at the current rate", a conclusion that was also that of other eminent climatologists present.

Indeed it is difficult to see how such a conclusion can be avoided if one accepts with Flohn, that we are already "on the fringe when man-made changes" to the chemical composition of the atmosphere "are at the same level as natural ones" - and are, what is more, still increasing. [102]

What hope is there?

In the introduction of the Fifth Report of the Royal Commission on Environmental Pollution, Mr Crossland, who was then Minister of the Environment, congratulates its authors for showing that there was no substance to the predictions by environmentalists that our industrial activities were causing irreversible damage to our environment.

In the same report, its principal author, Sir Brian Flowers, concludes that pollution could never by itself limit economic growth. These statements, which reflect official opinion in this and other countries as well, could not be further from the truth. Indeed if global environmental pollution were to increase at the current rate for more than a few decades, economic activities, like all other human activities, would be dramatically curtailed by the mere fact that our planet would have ceased to provide a suitable habitat for complex forms of life such as human and the other higher mammals.

In reality of course such a situation is unlikely to occur. Over the next decades our polluting activities are likely to diminish rather than increase. This, however, is not going to be because of any intelligent decisions taken either by our industrialists, or our politicians, but simply because world conditions are becoming ever less propitious to the industrial process. It is, in fact, global economic catastrophe that is likely to provide the only effective method of pollution control.

Notes