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MARCH 1969 Volume 11 Number 2 75 cents Presented at the Symposium on Unanticipated Environmental Hazards Resulting from Technological Intrusions convened by the American AssQ- ciation for the Advancement Advancement of Science Committee Committee on Science in the Pro- motion of Human Welfare and the Scientists Institute for Public Informa- tion Dallas Texas December 28 1968 ASBESTOS By I. J. Selikoff I DO NOT KNOw if it is entirely appropriate to consider our current problems with asbestos an unanticipated environmental hazard As I look back it would seem that we should have had some premonition For example 70 years ago H. Montague Murray then Senior Physician at the Charing Cross Hospital in London examined a man of 33 suffering with pulmonary fibrosis He had been working in the carding room of an asbestos textile factory Of the ten men working in that room thirteen years before he was the sole survivor He too died a year later at post mortem it was found that he had severely scarred lungs containing numerous asbestos fibers Dr. Murray described this case to the Departmental Committee on Compensation for Industrial Disease which after thanking Dr. Mur- ray noted that " . considerable trouble is now in 1907 taken to prevent the inhalation of the dust so that the disease is not so likely to occur as heretofore The disease which was referred to then had no name nor did it when Auribault described numerous deaths among French workers in an asbestos textile factory in 1906 nor did it when Pancoast found abnormal rays of the chest in 1919 in a group of American asbestos workers Surely taxonomy has a particular virtue in science individuals dying of this disease became much more evident when Cooke described another case in 1924 and 1927 and gave the illness its current name- asbestosis We can now accurately record for example that ten percent of the deaths among asbestos insulation workers in New York in the past 25 years were due to asbestosis The new category was soon replete with cases MARCH 1969 However comfort was provided this time in the Home Office Report put before the English Parliament in 1930. While pulmonary disease among asbestos workers in the past was acknowledged it was simultaneously concluded that the outlook was good In the space of a decade or thereabouts the effect of energetic application of preventive measures should be apparent in a great reduction in the incidence of fibrosis Such optimism persisted for the next 30 years asbestosis was acknowledged as a rather rare disease occasionally occurring among a small group of workmen employed in an isolated esoteric industry There were a few rumblings during this time whose echoes should perhaps embarrass us now Thus Kenneth Lynch reported a death from lung cancer in association with asbestosis in 1935 and several similar reports of this association between two then uncommon diseases followed For the most part however these reports were categorized as bibliographical curiosities Even the careful studies of Richard Doll reported in 1955 failed to disturb our calm perhaps because of the reticence with which the statistician summarized his findings Listing eighteen deaths due to lung cancer in 105 consecutive post mortem examinations at one asbes- tos works in England he concluded that . . lung cancer was a specific industrial hazard of certain asbestos workers " ... Even those who accepted Doll's conclusions there were some who did could point to a problem with a rather narrow spectrum A single neoplasm lung cancer was past tense a specific industrial hazard no hint that it could be more than this of certain asbestos workers the heavily exposed individuals in this factory In the past several years the spectrum has widened considerably First it has been recognized that the hazard associated with direct occupational exposure to asbestos is by no means a narrow or infrequent one The experiences of insulation workers in this country are instructive These men employed in the construction industry and often working doors and with materials containing only limited amounts of asbestos are much less exposed than many factory workers had been Yet their health experiences have been disastrous We have studied all members of the Insulation Workers Union in the New York metropolitan area On December 31 1942 there were 632 members of this Union Calculations in studiesby E. Cuyler Hammond J. Churg and myself indicated that by December 31 1962 according to life expectancy in the general population of U.S. white males there should have been 203 deaths among these men Instead there were 255 excess of twenty percent Using age year and specific rates there should have been six or seven deaths due to cancer of the lung or pleura Instead there were 45. There should have been nine or ten deaths due to cancer of the stomach or colon there were 29. There should of course have been no deaths due to asbestosis there were twelve Similar calculations to 1967 gave similar results Whereas 47 deaths were expected there were 94. Where eight or nine deaths due to cancer were predicted there were 49. Again there was a significant excess of specific types of cancer While there should have been two or three deaths due to cancer of the lung or pleura there were 27 and there were eight deaths due to gastrointestinal cancer against two expected Once more asbestosis claimed fifteen lives against none expected Studies are now under way in our laboratory of insulation workers in other parts of the country Mortality data indicate that the New York findings are unfortunately true elsewhere as well It not known exactly how many asbestos insulation work- ers are employed in the United States estimates range from 50,000 to 100,000 In the face of the mortality information one hopes the lower figure is more accurate Information is incomplete concerning the number of workmen in other trades in the United States A pioneer in modern asbestos epidemiology Dr. Irving J. Selikoff is Professor of Environmental Medicine at New York City University's Mount Sinai School of Medicine Director of its Environmental Sciences Laboratory and is also President of the New York Academy of Sci- ences He was awarded the American Public Health Association's Albert Lasker Award in Medicine for his research on isoniazid an antibiotic drug widely used in the treat- ment of tuberculosis with direct occupational asbestos exposure Totals of 100,000 to 125,000 are often proposed Again the lower figure is hoped for especially in view of the absence of satisfactory mortality information con- cerning such asbestos factory workers and since Mancuso's findings are disquieting Analysis of these mortality experiences is dis- turbing from another point of view in addition to its magnitude I refer to the occurrence of pleural TABLE 1 Observed and Expected Number of Deaths among 632 Asbestos Workers Exposed to Asbestos Dust Twenty Years or Longer 1943-1962 Cause of Death 19431947 19481952 19531957 19581962 Total 19431962 Total cancer all sites Observed 13 Expected 57 Cancer of lung and pleura Observed 6 Expected 0.8 . Cancer of stomach colon and rectum ..... . se Observed 4 Expected 20 Cancer of all other sites combined 1... Observed 3 Asbestosis .. Expected 29 ve Observed 0 17 8.1 8 1.4 4 2.5 5 4.2 1 Total all causes Expected Observed 28 Expected 39.7 54 50.8 26 130 13 2.0 7 26 6 8.4 4 85 56 39 9.7 18 2.4 14 2.3 7 5.0 7 88 54.4 95 365 45 6.6 29 94 21 205 12 less than 1 255 203 5 and peritoneal mesothelioma tumors of the lining of the lung and abdominal cavities among these workmen with direct occupational exposure During the 1950's there were several reports of deaths in asbestos workers caused by these diffuse tumors of the mesothelial surfaces Such isolated cases would have received little notice had it not been for the fact that the tumor has always been considered extraordinarily rare It is no longer rare among asbestos workers Indeed it is so common a cause of deaths among them while still rare among individuals not known to be exposed to asbestos to almost constitute a tumor specific to asbestos exposure Several reviews of autopsy files suggest that this rapid increase with hundreds of cases now known in Great Britain South Africa the United States and Canada is not due to refinement in diagnosis Thus review of all possible cases in several major pathology departments in Scotland has demonstrated an increase from one or two cases a year in the 1950's to some twenty cases a year or more at the present time Fourteen of the last 120 deaths in New York among asbestos insulation ENVIRONMENT VOL 11 No. 2 workers have been due to mesothelioma The problem has assumed sufficient importance to have warranted the establishment of Mesothelioma Reference Panels in a number of countries by the International Union Against Cancer and the recent establishment of a Mesothelioma Registry in this country by the National Institute of Environmental Health Sciences of the U.S. Public Health Service These experiences highlight one portion of the current spectrum of asbestos disease It is now recognized that direct occupational exposure to asbestos results in a hazard much more significant than formerly appreciated In the last several years however additional problems have been recognized which add another dimension the possibility that the utilization of asbestos is associated with a much wider risk perhaps one of the community at large This is less well defined much less well documented but because of its potential importance of considerable concern The recognition of this potentially wider spec- trum of asbestos disease has been based upon three germinal observations The first was the publication in 1960 by Wagner and his colleagues of 47 cases of mesothelioma in South Africa all from the northwest Cape Province an asbestos area of the country Analysis of the cases showed that few had worked directly with the mineral but that 15 of the 47 may have had contact with it often indirect They had lived in an area in which asbestos was mined or had worked in an environment in which indirect haphazard exposure was conceivable In striking contrast there were no cases of mesothelioma in the rest of South Africa reported in the TABLE 2 Observed and Expected Number of Deaths among 370 Asbestos Workers from January 1 1963 to April 30 1967 Couse of Death Observed Deaths Expected Deaths Ter Cancer of lung pleura bronchus and trachea Bronchogenic carcinoma Pleurci mesothelioma Peritoneal mesothelioma Cancer of stomach Cancer of Cancer of Asbestosis colon and rectum all other sites combined . Heart and circulatory disease including All causes of death Total all causes 49 86 27 23 22340525 AA *** 2 340525 2 340525 *** 2 340525 06 2340525 12 2 340525 45 22340525 . 22 28.5 8 104 94 47.5 US mortality data disregarding smoking habits States data not available but figure should be only 23 23 available but these are rare causes UPI Insulation workers employed in the construction industry have had disastrous health experiences even though their work is often outdoors and involves only limited contact with asbestos Up until the past several years it was thought that lung cancer from asbestos was an industrial hazard limited to the heavily exposed individuals in asbestos factories same period and none in 10,000 consecutive autopsies of individuals with silicosis This report unequivocally raised the question of whether asbestosassociated mesothelioma was limited to direct occupational exposure or whether much less intimate contact could produce the same result In the same year 1960 Kiviluoto raised an analogous question Pleural calcification had been known to occur frequently in characteristic form among asbestos workers In our experience indeed the majority of older asbestos workers may be expected to show these changes when rayed It was therefore striking to find typical asbestotic pleural calcification in 499 of 6,312 individuals rayed in one county in Finland while the neighboring county had none in 7,101 Kiviluoto astutely noted that the first county contained an asbestos mine and while none of the individuals with pleural calcification had worked in this mine they had lived nearby His countrymen Laamanen and his colleagues later demonstrated the presence of asbestos fibers in the air in the vicinity of the mine and while this may not reflect the true explanation for Kiviluoto's findings the question of environmental contamination was strongly suggested The third observation was equally sobering It had long been known that asbestos fibers when inhaled into the human lung may become coated with an rich characteristic golden brown material forming an asbestos body These are found for example in very large numbers in the lungs of asbestos workers In 1963 Thomson reported that he found bodies with the same appearance in the lungs of people who were not asbestos workers Smears of the lung bases allowed him to demonstrate these bodies in 26 percent of 500 consecutive autopsies in Capetown His conclusion was that asbestos had indeed become a modern urban hazard and he predicted that asbestos mesothelioma might become as frequent as cigarette ciated lung cancer is at the present time Thomson's observations have been widely confirmed and particles having the appearance of asbestos bodies have been reported in similar percentages in Montreal Milan London Newcastle Glasgow Belfast Dresden Pittsburgh and Miami In New York City using a somewhat more sensitive technique we find that approximately half of the lungs in 1,975 consecutive autopsies examined by us show these particles When one considers that we examine only one square centimeter of lung tissue 0.0175 centimeter in thickness it is obvious that these particles are now very common among city dwellers at this time Opportunity for occupational contact with asbestos at the present time can easily be discovered There are for example some three thousand products which currently utilize this valuable material To the present lack of recognition of the potential of occupational exposure has led to the absence of appropriate safeguards during industrial use Demolition of buildings often rich in containing materials is suspect while sheer carelessness and ignorance may explain its TABLE 3 Asbestos Bodies in New York City Dwellers Without Occupational Exposure Cases Male Female Age Total cases Total with asbes- tos bodies Percent with asbestos bodies Age Total cases Total with asbestos bodies Percent with asbestos bodies 0-1 2-9- 2-910-19 20-29 30-39 40-49 50-59 60-69 70-79 80-89 90+ Total 40 2 4 22 50 178 280 359 = 321 105 7 1368 0 i 0 4 14 83 149 205 180 62 4 702 ~- a % 28 47 53 57 56 59 % % 0-1 2-9 10-19 20-29 30-39 40-49 50-59 60-69 70-79 80-89 90+ Total 34 2 8 12 18 58 85 147 151 80 12 607 0 0 3 4 7 18 38 57 65 40 8 240 38 33 39 31 45 39 43 50 % 39 TABLE 4 Asbestos Bodies in Shipyard and Construction Workers Quantitative Results Blue Collar no Shipyard or Construction Total Number of Workers Workers Having Asbestos Bodies Workers Having No Asbestos Bodies Workers Having Five or More Asbestos Bodies 246 121 49 125 20 % Shipyard and Construction White Collar Males 129 90 70 39 206 87 42 119 29 23 10 % recommendation and use as playroom material in kindergartens or in toy cosmetics Indirect occupational exposure is suggested by recent observations in our laboratory We find for example that while approximately 30 percent of housewives examined at post mortem had asbestos bodies demonstrated comparable figures are 40 percent for white collar males and 50 percent for blue collar males This rises to over 70 percent for men with any history whatsoever of having worked either in the construction industry or in shipyards . The latter moreover are much more likely to have numerous asbestos bodies than any of the other groups A special hazard may be present as the result of an interaction recently described We have found that there is a special risk of cigarette smoking among asbestos workers Since January 1 1963 we have observed 87 experienced insulation workers who were not regular smokers or who were pipe or cigar smokers we have yet to see a death from bronchogenic carcinoma among these men On the other hand of 283 equally experienced workmen who smoked cigarettes and who were watched for the same period of time we have seen 24 such cancers although only three were expected We have calculated that the risk of dying of lung cancer is approximately 92 times greater for an asbestos worker who smokes cigarettes than a man of the same age who neither works with asbestos nor smokes cigarettes These observations naturally raise the question whether the inhalation of asbestos fibers among individuals in the general population might carry a special risk among the cigarette smokers in that population Wagner's observations have been extended by two recent studies Muriel L. Newhouse investigated 76 consecutive cases of mesothelioma examined at the London Hospital the majority within the last several years She found to no one's surprise that ENVIRONMENT VOL 11 No. 2 | 31 had been asbestos workers Much more unex- pected however was her discovery that nine had merely lived in the household of an asbestos worker raising the serious question of a special hazard of family exposure Then of the 36 who neither worked with asbestos nor had relatives who worked with asbestos eleven had lived within a half mile of an asbestos plant The latter cases of course suggested a special risk associated with neighborhood contact with asbestos Similar findings were reported by Jan Lieben last year in Pennsylvania Of 42 cases of mesothelioma reviewed by the Pennsylvania State Department of Health twenty had identifiable occupational exposure In addition eight individuals had lived within the vicinity of an asbestos plant and three had had family contact We have confirmed that family contact is a distinct possibility Sampling of both ambient air and settled dust in the homes of New York insulation workers has shown characteristic asbestos particles to be present presumably brought home on the clothes of the workmen It is obvious that the spectrum of asbestos disease has considerably widened in the last several years In addition to lung cancer and asbestosis a number of other tumors are now recognized as constituting a hazard Rather than a small number of heavily exposed workmen a large number are involved in less intense direct occupational exposure or even in indirect occupational exposure The latter may represent a real problem there are for example 3,500,000 men employed in the construction and shipbuilding industries or five percent of the total employed population in the United States Significant exposure may even extend to the families of these men and perhaps to residents in the neighborhoods surrounding their places of employment Finally this ubiquitous material may well be found to permeate the community at large What such exposures may bring is not now known Disease associated with asbestos is rarely seen sooner than 20 to 30 years from the onset of exposure York Thus among our insulation workers in New I have yet to see a mesothelioma in a man who began work after 1930 or a case of lung cancer in an asbestos worker who had worked in that industry less than twenty years Our concern is with the future At the outset of this presentation I questioned whether asbestos might properly be included as an unanticipated environmental hazard Yet the less iconoclastic among us might have countered with it must have been could not have knowingly allowed this to come to pass Surely the explanation lies in the length of the period that elapses between exposure and disease which kept us from really knowing the problem until now MARCH 1969 Perhaps so Indeed I do not share the demono- logical theory of industrial hygiene history in which industry is seen as callously exchanging human disease for profits Rather I would say industry shared the ignorance and lethargy of us all The answer will come in these next several years We have some reason for optimism First we have the law of averages on our sooner or later some important environmental hazard is bound to be controlled I suspect asbestos will be one We have reason to believe that the disease relation- ship is on our side the present disease has been uncommon except with significant exposure And our data suggest further that such significant ex- posure can be prevented that we can learn to live and work with asbestos All it will take is the doing -but herein lies another tale Oo NOTES p 3 ..w. hen Auribault described . 11 Auribault M. Observations regarding the Hygiene and Safety of Workers in Asbestos Spinning and Weaving Mills Bulletin de l'Inspection du Travail p 126 1906 Cooke described another case . " Cooke W. E. Fibrosis of the Lungs Due to Inhalation of Asbestos Dust British Medical Journal 147 1924 40 the careful studies of Richard Doll Doll R. Mortality from Lung Cancer in Asbestos Workers British Journal of Industrial Medicine 12:81 1966 p 4 68 studies by E. Cuyler Hammond J. Churg and myself Selikoff I. J. J. Churg and E. C. Hammond Asbestos Exposure and Neoplasia Journal of the American Medical Association 22-26 April 6 1964 Relation between Exposure to Asbestos and Mesothelioma New England Journal of Medicine 560-65 1965. Selikoff I. J. R. A. Bader M. E. Bader J. Churg and E. C. Hammond Editorial Asbestosis and Neoplasia American Journal of Medicine 487-496 1967. Selikoff I. J. E. C. Hammond and J. Churg Asbestos Exposure Smoking and Neoplasia Journal of the American Medical Association 106-112 April 8 1968 Selikoff I. J. and E. C. Hammond Community Effects of occupational Environmental Asbestos Exposure American Journal of Public Health 1658-1666 September 1968 sinc e Mancuso's findings Mancuso T. S. and E. V. Coulter Methodology in Industrial Health Studies The Cohort Approach with Special Reference to an Asbestos Company Archives of Environmental Health 210 February 1963 p 5 * .. the publication . . . by Wagner and his colleagues Wagner J. G. C. A. Sleggs and P. Marchand Diffuse Pleural Mesothelioma and Asbestos Exposure in the North Western Cape Province British Journal of Industrial Medicine 260-271 1960 " Kiviluoto raised an analogous question Kiviluoto R. Pleural Caleification as a Roentgenologic Sign of occupational Endemic Anthophyllite Acta Radiologica Supplement 1-67 1960 p 6 ",.. Thomson reported . Thomson J. G. Exposure to Asbestos Dust and Diffuse Pleural Mesotheliomas British Medical Journal 123 Jan. 12 1968 Hazard Thomson J. G. et al Asbestos as a Modern Urban South African Medical Journal 77-81 Jan. 19 1963 Muriel L. Newhouse investigated " - ** Newhouse M. L. and H. Thompson Mesothelioma of Pleura and Peritoneum following Exposure to Asbestos in the London Area British Journal of Industrial Medicine 261-269 Oct. 1965 Similar findings were reported by Jan Lieben " " Expo- Lieben Jan and H. Pistawka Mesothelioma and Asbestos sure Archives of Environmental Health 559 April 1967