Mr W. P. Howard, Secretary of The Asbestos Information Committee has written to us attempting to refute the statement made in The Ecologist Vol. 3 No. 1 (“Asbestos and cancer”), to the effect that “low levels of asbestos in the air increase the risk of cancer to the general public”. This is our response.
A great deal is known on the effect of asbestos on human health. Thus Merewether and Price in their extensive survey of asbestos workers in England found that 80 percent of those who had worked 20 years or more in this field displayed symptoms of this disease. Similar evidence was found by Bohme in Germany. He showed that morbidity rates increased with length of exposure, reaching a 79 percent rate for workers exposed for more than 10 years. Other studies have obtained similar results.
Another disease associated with asbestos pollution is the calcification of the pleura. the depositing of insoluble calcium salts in the lining of the lung. A Finnish study showed that this disease was observed in 499 of 6,312 people living near an asbestos mine. In about 7,101 people living elsewhere, no cases were recorded.
The most serious disease associated with asbestos is cancer. Merewether the Chief Inspector of Factories in the UK in 1947, stated that out of 235 reported cases of men who had died of asbestosis between 1924 and 1937, 31 had lung cancer – 13.2 percent.
Professor Richard Doll has reached the conclusion that asbestos workers run a 10 times greater risk of contracting lung cancer than the general population. A massive study was undertaken by the Asbestos Workers’ Union in New York and New Jersey which revealed a 60 percent higher death rate than in the normal population. Deaths were caused by lung cancer, cancer of the pleura, cancer of the gastrointestinal tract and asbestosis. Another study of 17,800 workers in the US and Canada (1967 – 1971) yielded similar results.
Very disturbing is the synergy between asbestos and cigarette smoke. It was estimated in the above study that asbestos workers who smoke have a 92 times greater risk of dying of lung cancer than men who neither work with asbestos nor smoke.
Asbestos is also linked with abdominal mesothelioma – also a form of cancer. This was established in 1960 in a study in South Africa. Studies in New Jersey reported high incidences of this disease in a community living in the vicinity of a large asbestos mill. Asbestos also appears to cause intestinal and uterine cancer and perhaps cancer of other organs. It was found in a recent study in Pittsburgh, that 98 percent of lungs examined contained asbestos fibres. In New York, 3,000 autopsies revealed 1,449 cases of lungs containing asbestos bodies. Pleural calcification has also been associated, in Finland, with non-occupational exposure to asbestos.
In the US legislation is beginning to appear to control the use of this very dangerous pollutant. Recently in Philadelphia, a court ruled that it was a criminal offence to spray asbestos at a building site. A City ordinance in Philadelphia now prohibits the spraying of asbestos-containing material at construction sites. The Environmental Protection Agency has recently proposed emission standards for asbestos from all mining, milling, spraying and manufacturing processes.
To understand the relevance of this information to human health today, we must realise that lung cancer is very much a disease of industrial society, in fact it appears to increase in direct proportion to industrialisation and hence GNP. Thus, if we take a country like Ceylon with GNP per capita of $140, the lung cancer incidence among males is 5 per million. In Mauritius, with per capita GDP of 225 dollars, the incidence is 16 per million; in Portugal, a much richer country, with per capita GDP of $479, the incidence is 130 per million; and in the US where the average income is $3,960 the incidence is 430 cases per million.
What are the features of industrialised society that make its members so vulnerable to this disease? I think that all those who have looked into the problem will agree that the main thing is that we are all exposed to well over half a million different chemicals of which the human organism has had no experience during the course of millions of years of evolution, and the number is increasing by 3,000 or 4,000 every year. It is for this reason that cancer, diabetes, heart diseases etc, often referred to as the diseases of civilisation, are becoming known as the diseases of maladjustment.
One of the most important facts that neither the government nor our establishment scientists have been willing to recognise is that the experimental method, consisting of examining the effects of each specific pollutant on laboratory animals, cannot possibly provide the necessary information to reduce the ever growing cancer rate.
There are many reasons for this, all of which I cannot go into here. One is that different experiments reveal different results because the exact conditions under which they take place are never the same and also results invariably lend themselves to different interpretations. Another is the immense problem of logistics involved. There are simply not enough laboratories or laboratory technicians in the world to carry out all the necessary experiments.
The SCEP report makes this point very clearly:
“The significant aspect of human action is man’s total impact on ecological systems, not the particular contributions that arise from specific pollutants. Interaction among pollutants is more often present than absent. Furthermore, the total effect of a large number of minor pollutants may be as great as that of one major pollutant. Thus, the total pollution burden may be impossible to estimate except by direct observation of its overall effect on ecosystems.”
On the basis of this essential principle the case against asbestos is far stronger than it need be to justify the strictest possible controls on its manufacture and use, if not an outright ban.
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