Document kDmykb9ZojM096xQZpVDMJEJq

Proportion of Cancer Due to Exposure to Asbestos* by Fhilip E. Enterline.** 1 FINAL If the current level of cancer mortality continues nearly 50 million persons alive today in the United States will die of cancer. This prediction could be modified by the discovery of better methods of treatment, or by altering known cancer causing exposure patterns. Since resources are finite it is important to allocate these so as to achieve greatest impact on the cancer problem. For this reason it would be useful to know the proportion of cancer due to various environmental agents. This kind of effort has been greatly stimulated by a widely quoted document, sometimes referred to as the "estimates" document, that concludes that 13-13.5 of all cancer is caused by a single substance--asbestos (Eridbord et al. 1978). There has been disagreement with this estimate (Higginson et al. 1980; Peto I960; Hogan and Eoel 1981). Current Approaches One approach to the question of how much cancer is caused by asbestos is to find a well reported disease clearly caused by asbestos exposure and from epidemiologic investigations calculate the ratio of this disease to all cancer caused by asbestos. Higginson, for example, has noted that there are about 1,000 Presented at a conference on the Quantification of Occupational Cancer, Banbury Center, Cold Spring Harbor Laboratory, March 30, . 1981. Professor of Bicstatistics, Graduate School of Public Health University of Pittsburgh, Pittsburgh, ?A 15261. APC 003647 annual mesotheliomas In the United States, and that In a long terra mortality study of heavily exposed asbestos workers for every one mesothelioma there were about 1.5 bronchogenic cancers related to asbestos (Higginson et al. 1980). Prom this he estimated the total annual Incidence of asbestos caused bronchogenic cancer In the United States to be about 1,500. This makes up 2% of the approximately 70,000 such deaths each year. Higginson's report leads to an estimate of 4,000 asbestos caused cancers In the U.S. each year (Including mesotheliomas) or 1J5 of the total 400.000 cancer deaths that occur annually. Another approach Is to estimate the number of 'asbestos 'exposed workers and based on epidemiologic studies of subsets of this or other populations, predict the proportion and numbers of these asbestos exposed workers who will develop cancer as the result of asbestos exposure. This is the approach used'by the group that produced the "estimates" document. In that study It was estimated that 4 million workers alive today have had a heavy asbestos exposure like asbestos workers, and based on data from a study of asbestos insulators. It was calculated that 1.6 Billion or 40S of these are expected to die of asbestos related e&ncers. It was estimated. In addition, that 1.5-3-.5 million workers have had lesser exposures and .4 to .7 million of these will die of asbestos related cancers. Thus, over the next 30-35 years the expected number of cancer deaths associated with asbestos Is between 58,000 to 75,000 per year or 13-18J6 of the 400,000 to 450.000 cancer deaths that occur each year. Bogan and Hoel- have used essentially the same approach followed in the "estimates'* document but with different results (Hogan and AFC 003648 Hoel, 1931). They estimated that 7-8 million workers were .potentially exposed to asbestos during the years 19^0-67 of which 50% are alive today. Of these 15% were heavily exposed and will have cancer mortality rates like asbestos insulators, while the remainder will have 1/8 to l/1! this cancer risk. On this basis they estimate that future excess cancer deaths due to asbestos exposure will contribute 3? of all cancer deaths (range l.h--. Heavily Exposed Workers In thinking about the. problem of asbestos caused cancer it helps to consider the magnitude of another health problem related to asbestos-asbestosis. Asbestosis was seen In asbestos workers long before cancer, and In fact it was the high frequency of .coexisting asbestosis and lung cancer that led to the conclusion that asbestos was a cause, of lung cancer. In the past many felt that asbestosis was a prerequisite for asbestos lung cancer and that prevention of asbestosis would also prevent lung cancer (Eckardt 1959). It is partly for this reason that the present TLV for asbestos is based on preventing asbestosis rather than lung cancer. Moreover, many also feel that only very heavy asbestos exposure Is likely to lead to an asbestosis death and that the presence of asbestosis at death is important since it Indicates the heavy exposure needed to produce asbestos lung cancer (Wagner 1965). Table 1 shows asbestosis deaths observed in the United States during the period 1950-77 by year, sex and race. Clearly the trend is upward until 1972 when numbers of deaths seem to have ARC 003649 leveled off. It Is Important to note that all asbestosis deaths observed in epidemiologic studies conducted in the United States are included in the numbers shown in Table 1. It is possible for each study, then, to see how Its asbestosis deaths related to the U.S. total and thus estimate the size of the population which produces all asbestosis deaths in the entire United States. One estimate can be made from a. study we conducted in the early lS60's. In that study we identified 21,755 male white workers from 35 of the larger U.S. asbestos products plants (SIC 3292) where we can be fairly certain exposures were high (Enterline and Kendrick, 1967). These workers had all been first employed sometime during the years 19*18-51. During the years 1950-63 at ages under 65 there were ft1! deaths from asbestosis.* During the same period it can be seen from Table 1 that for the entire United States the number of deaths from asbestosis at all ages among white males was 18*1. Tabulations of asbestosis deaths by age are available for the years 1962-77. During that period 525? of all asbestos deaths were at ages under 65. From this it can be estimated that there were 96 deaths from asbestosis at ages under 65 during the years 1950-63. Thus, this population of 21,755 workers produced *15.8 percent of the asbestosis deaths that occurred in the U.S. among white males at ages under 65 during the years 1950-63. From this it can easily be calculated that the total number of white males producing asbestosis deaths at ages under 65 (exposed like asbestos products workers) must have been equivalent to *17, **65. Since the ratio Only deaths at ages under 65 were examined in this study. APC 003650 of all deaths In Table 1 to white male deaths is 1.23 for the years 1950-63 this suggests a total population producing asbestosis of 58,381. In another study, of 1075 retired male asbestos products workers from a single asbestos company at ages 65 and over, we observed 17 asbestosis deaths during the period 1950-73 (Henderson and Enterline, 1979). During the same period In the entire U.S. it can be calculated from Table 1 that there- were 515 male deaths due to asbestosis of which an estimated 48' or 248 were at ages 65 and over. Thus, the total population at ages 65 and over producing asbestosis deaths must have been 15,683. Again adjusting to the total population this becomes 17,054. The total at all ages, therefore, must have been 75,435. Another estimate can be made from a large study by Selikoff and his co-workers of 17,800 male asbestos Insulators from the United States and Canada (Selikoff et al. 1980). These workers were observed for deaths over the years 1967-76 and 78 deaths were coded from death certificates as due to asbestosis. It's not reported how many of these were Canadian workers, but perhaps about 10S so that we can estimate asbestosis deaths among U.S. asbestos Insulators at about 70. Table 1 shows that during the same period In the entire U.S. there were 371 male deaths from asbestosis. Thus, from these data we can estimate that during the years 1967-76 these asbestos Insulators produced 18.93 of all male asbestos deaths. The total U.S. male population producing asbestosis deaths (exposed like asbestos Insulators) was, therefore, equivalent to 84,906. This is somewhat higher than the estimate made on the basis of asbestos products workers, but since it relates to a later APC 003651 period (1967-76) it may reflect the presence of a larger heavily exposed population. These two study populations produced over half of all the concurrent asbestosis deaths in the United States and point clearly to the importance of asbestos insulators and asbestos products workers in estimating heavily exposed populations. That asbestos insulators and asbestos products workers are the primary source of asbestosis deaths is confirmed by individual case reports which almost entirely represent occupations of asbestos insulator and asbestos products worker (McVittie 1965). Actual numbers of asbestos insulators and asbestos products workers are published regularly by the U.S. Government. Table 2 shows the number of workers employed by asbestos products companies in the U.S. (SIC 3292 ) for the years 19*17-76, the membership of the International Association of Heat and Frost Insulators and Asbestos Workers, and asbestos and Insulation workers reported in each decennial U.S. census. The number f insulators increased steadily during the period 1950-76 from around 15 to 25 thousand. On the other hand the number of workers employed by asbestos products producers stayed at around 20,000 during the 1950's and 1960's but dropped rather sharply In the 1970's.* The period of interest is the period prior to 1970 since after that time increased awareness of the health hazards associated with asbestos probably greatly decreased the cancer risk. In addition to workers in asbestos products Industries (SIC 3292), there are workers making asbestos paper included In a larger category "Building paper and building board mills" (SIC 2611) and asbestos exposed workers in a category "Steam and other *Irr our 19o7 study we Identified 12,707 white males working In the first quarter of 19H8, so our cohort apparently contained over half of all workers employed by asbestos products companies in 19*18. ApC 003652 packing, and pipe and boiler covering" (SIC 3293)- A 1976 study by Weston Environmental Consultants places the total employment in primary asbestos products industries at 37,539 of which an estimated 22,670^are exposed to asbestos. How many asbestos products workers and asbestos Insulators employed during the period 19*10-70 are alive now in 1981? Prom data in Table 2 it appears that on average during the period 19^7-70 there might have been about *10,000 such workers in the United States. Our .experience in carrying out historical prospective studies of working populations is that over a 30 year period the number of different workers with a year .or more work experience is about 3 times the average daily worker census. Thus, I would estimate that an average census of 1)6,000 asbestos products workers and asbestos insulators over the period 19*10-70 represents 120,000 different workers with a year or more work experience. Of course, all these workers would not be alive today. Assuming a death rate of 1? per year, somewhat higher than the U.S. death rate but similar to the annual death rate observed in the study of 17,800 asbestos insulators, and a mid point of 1955 we would expect about 85? or about 100,000 to be alive in 1970 and, if no new heavily exposed workers have been added since that time, somewhat less in 1981 -- say about 90,000. These estimates are somewhat higher than those made on' the basis of asbestosis deaths, but indicate that certainly less than 100,000 workers and former workers are alive today who had exposures to asbestos like asbestos insulators and asbestos products workers. I would estimate that as of 1981 there are between 70 and90 thousand persons alive in the U.S. who have had heavy asbestos APC 003653 exposure--mostly present and former asbestos insulators and asbestos products workers.* This is very low in contrast to estimates made by others, but is in line with an estimate of 20,000 "high risk" workers in the United Kingdom, where the population is about a quarter as large as the U.S. population (Smither 1979). Assuming a best estimate of 80,000 heavily exposed or high risk workers alive in 1981 how many of these will die of asbestos lung cancer? Since we have actual epidemiologic data on both asbestos products workers and asbestos insulators this is not difficult to estimate. If data from the cohort of 17,500 asbestos Insulators is used to predict, it appears that after 20 years from first exposure 222 will die of asbestos lung cancer (Selikoff et al. 1980).** If data from cohorts of asbestos products workers were used this percentage would be somewhat lower. Among retired asbestos products workers from the Johns Manville Corporation about 14'2 died of asbestos lung cancer, while in a study of workers from a British asbestos textile plant 152 died from asbestos lung cancer (Henderson and Enterline 1979j Peto et al. 1977). If we can assume 202 Is a good overall estimate for the entire *1 had earlier estimated somewhere between 43,000 and 1,700,000 heavily exposed workers alive in 1967, with a best guess of 250,000 (Hogan and Hoel 1981). The reason for the best guess of 250,000 was that at that time death certificate data on the number of deaths among the 17,800 asbestos insulators had not been reported and I assumed that death certificates showed far fewer than 78 asbestosis deaths. **This is calculated as: Percent erce-s - Observed Lung Cancer Expected Lung Cancer . rercent excels Expected Deaths from All Causes APC 003654 cohort then the number of asbestos lung cancers which will appear in this group of 80,000 is 16,000. If this cohort live just 30 more years asbestos lung cancer deaths will occur at a' rate of 530 per year. Less Than Heavily Exposed Workers It was Hueper's view that heavy exposure to asbestos dust produced asbestosis, whereas lower levels permitted lung cancer to develop (Heuper 1955). He was undoubtedly right, and the cancer problem is not confined to heavily exposed workers, but rather includes those more lightly exposed - so that, there is a population of exposed workers that does not experience many asbestosis deaths, but which does have an increased cancer risk. Populations most frequently mentioned are shipyard workers, construction workers and automotive brake mechanics. World War II Shipyard Workers Hogan and Hoel (1981) have estimated that during World War II there were ^. 3--5 - million shipyard workers exposed to asbestos and that perhaps 505 of these or about 2.5 million are alive today. The only data that appear to apply to the probable lung cancer excess in these shipyard workers are those published by Blot et_ al. (1978, 1980). In two case-control studies Involving interviews of lung cancer cases and a matched control group relative risks for lung cancer among World War II shipyard workers of 1.6 and 1.7 were calculated. APC 003655 In view of the fact that World War II shipyard and employment must have been fairly brief and, for occupations other than asbestos Insulators, exposure levels must have been relatively low these risks are surprisingly high. From labor turnovers rates It appears that the average duration of employment in the shipyard was about a year (Selikoff et al. 1979). Moreover, shipyards only operated at high employment levels for 2 or 3 years. Under these conditions the entire cohort would have had to be exposed to very high levels of asbestos to produce relative risks of 1.6 and 1.7.* As Blot et al. point out, however, the comparison of occupational histories between cases and controls may have been effected by a lower interview response rate among controls and by publicity surrounding the issue of asbestos and cancer. The second point needs emphasis in light of a report by Nigerian and Colton (1979) of a five-fold excess in leukemia among shipyard workers exposed to ionizing radiation based on a similar kind of case-control study. Subsequently, they discovered that reports of occupational histories by next-of-kin for decedents were biased by the knowledge that radiation and leukemia were related (Colton 1979). This was confirmed by a recent historical prospective study which shows no excess in leukemia among radiation exposed workers in the same shipyard (Rinsky et al. 1981). More direct evidence that brief casual exposure in World War II shipyards probably caused little lung cancer excess comes from a recent *6n the basis of a 22? lung cancer excess observed among asbestos insulators where exposure apparently averaged 25 years at 8 f/cc . it c.an be estimated that a 2 1/2? excess (RR = 1.H.). after one years exposure would require continuous exposure at around 22 f/cc. APC 003656 study of shipyard workers in Hawaii which shews essentially no excess in lung cancer followed 15-24 years and exposed to asbestos for less than 10 years (Kolonel et al. 1980). This study also indicates that about 4o.* of shipyard workers have no asbestos exposure at all. To apply a 1.6-1.7 relative risk to this large cohort of former shipyard workers seems inappropriate. One way to predict lung cancer deaths among the cohort of 2.5 million former World V.'ar II shipyard workers alive today Is by extrapolation from the several studies of asbestos insulators and asbestos products workers. To do this some estimate of the actual exposure levels Is needed. The time weighted asbestos exposure for insulation workers has been estimated at 4-12 f/cc (Nicholson 1976). What might the exposure of other exposed shipyard workers have been? There are no published data for shipyard workers to answer this. However, an informed guess is that during World War II for those workers actually exposed to asbestos, fiber counts were probably around 2 f/cc (Thorton 1981).* From the study by Kolonel (1980) we can estimate that about 60!$ or 1.5 million of the 2.5 million World War II shipyard workers were actually exposed to asbestos. For these 1.5 million workers alive today with a years exposure at 2 f/cc nearly 4o years ago we can estimate future asbestos lung cancer incidence by extrapolation from asbestosinsulation workers data. From data on asbestos products workers and asbestos miners it appears that the dose-response relationship is linear (Enterline and Henderson 1979; McDonald 1974). Moreover a time weighted measure of exposure -seems appropriate since intensity and duration Current (1979) fiber counts in one shipyard ranges from .08 to .66 (Matanoski, 1931). APC 003657 appear to make roughly equal contributions to lung cancer Incidence (Enterline et al. 1973; McDonald et al. 197*0. If for asbestos Insulators the exposure averaged 8 f/cc ( *1-12 f/cc) on a continuous basis and produced a 22% excess in mortality for lung cancer after about 25 years of exposure, we can easily calculate the excess for a single years exposure at 2 f/cc. The total exposure for asbestos Insulators needed to produce a 22% excess In mortality due to asbestos lung cancer can be calculated as (8)(25) = 200 fiber years. For shipyard workers, on the other hand, exposure would have been (2)(1) = 2 fiber years. Therefore, we can calculate that the percent cancer excess In the 1.5 million World War II shipyard workers will be 2/200 or l/100th of the lung cancer excess in asbestos insulators, or a .22? excess. Applied to the 1.5 million workers alive today this suggests 3,300 will die of asbestos lung cancer. If these workers live Just 20 more years this is about 165 excess deaths per year. Post World War II Shipyard Workers . A much more important population consists of workers who continued employment in shipyards after World War II, or were hired after World War II since their exposure lasted a considerable period of time. Shipyard employment is reported to have been around 200,000 since 19**5 (Selikoff et al. 1979). Assuming labor turnover as In the' industrial cohorts we have studied this would produce about 600,000 different workers with a year or more APC 003658 work experience.* With a mortality rate at 1? per year we would expect 528,000 of these to be alive in 1970 and about *175,000 to be alive today. Based on the Kolonel study (1980) we can estimate that 205,000 of these were exposed to asbestos. There have been several epidemiologic studies dealing with long term shipyard workers. Three of these show a clear lung cancer excess like the Blot et_ al. study (Puntoni et al. 1979; Kolonel 1980; Gottlieb 1980), one an Intermediate excess (Milham 1976) and two essentially no excess (Lumley 1976; Beaumont 1980). These offer little consistent guidance for estimating a lung cancer excess. However, an informed guess as to post World War II continuous fiber levels is around 1 f/cc for those exposed, so we can estimate the lung cancer excess as for World War II shipyard workers (Thorton 1981). Assuming continuous exposure was at 1 f/cc for 25 years and projecting from the experience of asbestos insulators we would expect the excess in lung cancer to be 25 or 1/8 the excess in asbestos insulators. Thus, of the 285,000 workers alive today 2.7? or 7,695 would be expected to die of asbestos lung cancer. Over the next 30 years this would average 256 deaths per year. This estimate of excess lung cancer yields a relative risk of 1.4, which is a rough average of relative risks actually reported for long term shipyard workers. *This is consistent with a count made by Matanoski (1981). As part of a study on the health effects of low level radiation she has estimated that there have been nearly 500,000 workers employed, at shipyards now employing about 120,000 workers. APC 003659 Auto Mechanics and Garage Workers Frequently mentioned as an asbestos exposed population are auto mechanics and garage workers. This population has been estimated at about 900,000 continuously exposed to asbestos (Weston et al. 1976). Since World War II this number has probably grown considerably and might have averaged around 750,000 over the period 19^0-70. Again, using experience from Industrial epidemiologic studies, we might estimate that there were 2.2 million workers exposed a year or more. At a death rate of 1% per year 1.9 million would have been alive in 1970 and about 1.7 million alive today. Studies indicate that the asbestos fiber concentrations to which auto mechanics and garage workers are continuously exposed are around .3 f/cc, well below that for shipyard workers (Hickish and Knight 1970). Probably the most applicable epidemiologic studies for estimating the effects of this kind of exposure comes from asbestos products workers. One study provides estimates of actual fiber exposure (Peto 1977). In that study the lung cancer excess was 15? and historic fiber concentrations were around 12 f/cc.* Exposure was about 25 years duration. Extrapolating from / ^\ \ *7 C that experience permits an estimate of a (^5) (12')' = 3UU" or (,025) (15) s .375? lung cancer excess. Applied to a population of 1.7 million this suggests 6,375 asbestos lung cancer deaths, over the next 30 years or 212 deaths per year. Substantially higher exposure estimates appear in a paper Just made .available but which the author feels must be regarded 'as provisional (Peto,- L. Lung Cancer and Measure Dust Levels, Biological Effects of Mineral Fibers edited by J.C. Wagner, IARC, Lyon, 1930). APC 003660 Secondary Asbestos Products Weston Environmental Consultants estimate that there are 240.000 employees in manufacturing operations using asbestos products and whose exposure is fairly high. Prom their data it appears that exposure of these workers is around 2 f/cc. Considering this group of industries during the period 1940-70 and a mortality rate of 1% per year there are probably about 5^0,000 workers and former workers alive in 1981. If historic fiber counts were double the counts available when Weston made its survey (4 f/cc), workers had an average of 25 years employment and if the experience in the primary asbestos Industries applies, then we can estimate that 5% of this population or 27,000 will die of asbestos lung cancer. This is 9C0 deaths per year over the next 30 years. All Other Workers Finally, what about all other potentially exposed workers In the United States? This must include construction workers, other workers using asbestos at their jobs, plus workers employed very briefly (< 1 year). A few of these might be in Jobs with heavy but unrecognized exposure. The 1973 NIOSH Occupational Hazards Survey Identified 1.6 million workers In the U.S. potentially exposed to asbestos of which 430,000 were in construction and 648.000 were in manufacturing. We have thus far dealt only with 40,000 heavily exposed, 240,000 secondary asbestos products workers, 200,000 shipyard workers, and 900,000 auto mechanics and garage workers. It's not entirely clear how these groups. . relate to the 1.6 million workers Identified by the Occupational APC 003661 Hazards Survey. I'any garage workers and auto mechanics appear to have been omitted. If so there must be over a million workers with potential exposures, many from the construction industry, that still need to be accounted for. I would estimate this represents 3.5 million persons alive today. Considering occasional exposures and brief exposures as well as some longer or heavy exposures, I would estimate an exposure equivalent to .3 f/cc for 25 years---like garage workers and auto mechanics. Projecting as before from the experience of asbestos products workers yields an estimated lung cancer excess f or (.025H.15) = .375#. Applied to a population of 3.5 million this yields an estimate of 13,1*10 asbestos lung cancer deaths or *133 deaths per year over the next 30 years. Table 3 summarizes the results of these calculations vrith regard to asbestos lung cancer. To this I have added other cancers resulting from asbestps exposure under the assumption that for every 2 asbestos.lung cancers there is one other cancer. I have also added a third of the approximately 1000 mesotheliomas that occur in the U.S. each year on the grounds that at least two thirds are due to exposures other than occupational exposures to asbestos ("cDonald 1980). The total ^084 extra annual cancer occupational asbestos deaths is about 1? of all cancer deaths in the United States. Finally deaths due to nonoccupational exposures to asbestos have been added. Asbestos lung cancer is estimated under the assumption that background is 1.5 ng/m^ or .00006 f/cc (Nicholson et al. 1978). Predicting from asbestos products workers, but assuming continuous exposure rather than 8 hours per day, 5.days per week. APC 003662 and assuming 70 years exposure suggests 23 asbestos lung cancer deaths per year for the entire United States: ^ ( ^24) x x ? Y0? =28. I have added an estimate of mesotheliomas produced by nonoccupational exposure under the assumption that two thirds of all mesotheliomas are due to asbestos and the rest due to something else (McDonald 1980). Discussion Prom available information it appears that about 1% of all cancer is due to asbestos exposure. This means that elimination of all asbestos from our environment would have an imperceptible effect on the cancer problem. It would ultimately have a great effect on asbetosis and mesothelioma deaths, but these are relatively unimportant as causes of death. We can pinpoint some populations at high risk of cancer as the result of asbestos exposure and some special effort might be made here.. Asbestos products workers and asbestos insulators exposed mostly before adequate controls were put in place for their protection are clearly high risk populations. The identities of most of the workers are known either to the asbestos workers .union or to the government. Efforts to prevent disease in this population would be an .important public service to them, although almost meaningless effort in terms of the overall cancer problem confronting us. Perhaps there are other such populations. I would be concerned about workers using asbestos products in the secondary asbejstos products industry. For example workers making asbestos gloves, from' asbestos textile. These are usually small APC 003663 highly competitive operations and dust control efforts may some times be inadequate. It would be satisfying to believe that a single substance within cur ability to control is responsible for a large part of an otherwise mysterious problem. Unfortunately this is not often the case. The role of asbestos in our overall cancer problem has been greatly exaggerated. One reason may be that we are becoming accustomed to exaggeration in dealing with environ mental hazards In the belief that this somehow protects people, and Is In the public interest. This may be true in initially drawing attention to a situation, but in the long run exaggeration is foolish since it leads to a wasteful effort and diverts resources from morefruitful areas. Moreover, falsely designating populations at high risk involves other human costs and is clearly not In the public interest. APC 003664 r References 'Beaumont, J.J. and H.S. Weiss. 1980. Mortality of welders, ship- fitters, and other metal trades workers in boilermakers Local No. 10H, AFL-CIO. Amer. J. of Epid. Vol. 112, No. 6:775-786. Blot, W.J., J.'M. Harrington, A. Toledo, R. Hoover, C.W. Heath, Jr. and J.F. Fraumenl. 1978. Lung cancer after employment in shipyards during World War II. New Eng. J. Med.:620-623, Sept. 21. 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N.Y. Acad. Sci. 132/1:128. Kilham, S. 1976. Occupational mortality in Washington State, 1950-71. Vols. I, II, III. National Institute of Occupational Safety and Health Research Report. Nicholson, W.J. 1976. Case study 1: Asbestos--the TLV approach. Occupational Carcinogenesis. U. Saffiotti and J.K. Wagoner (eds.), Vol. 271:152, New York Academy of Sciences, New York, New York. Nicholson, W.J. 1978. Control of sprayed asbestos surfaces in school buildings: A feasibility study. Report to the National Institute of Environmental Health Sciences, June 15- Nigerian , T. and T. Colton. 1978. Mortality from leukemia and cancer in shipyard nuclear workers. Lancet i:1018-1020. Peto, J., R. Doll, S.V. Howard, L.J. Kinlen and H.C. Lewinsohn. .. 1977. A mortality study among workers in an English asbestos factory. 3r. J. Indus. Med. 3^:169-173. Peto, J. 1980. Distorting the epidemiology of cancer: The need for a more balanced overview. Nature (Features) 284:297-300. Puntoni, R. M. Vercelli, F. Merlo, F. Valerio and L. Santi. 1979. Mortality among shipyard workers In Genoa Italy. Health Hazards of Asbestos Exposure. I.J. Selikoff and E.C. Hammond (eds.) Vol. 330:353, New York Academy of Sciences, New York, New York. Rinsky, R.A., R.D. Zumwalde, R.J. Waxweiler, U.E. Murray, Jr., P.J. Bierbaum, P.J. Landrigan, M. Terpilak and C. Cox. 1981. Cancer mortality at a naval nuclear shipyard. Lancet, January 31. APC 003667 Selikoff, I.J., E.C. Hammond and H. Seidman. 1979. Mortality experience of Insulation workers In the United States and Canada, 19^3-1976. Health Hazards of Asbestos Exposure. I.J. Selikoff and E.C. Hammond (eds.) Vol. 330:91, New York Academy of Sciences, New York, New York. Selikoff, I.J., R. Lilis and W.J. Nicholson. 1979* Asbestos disease In United States shipyards. Health Hazards of Asbestos Exposure. I.J. Selikoff and E.C. Hammond (eds.) Vol. 330:295, New York Academy of Sciences, New York, New York. Selikoff, I.J., E.C. Hammond and H. Seidman. 1980. Latency of asbestos disease among insulation workers in the'United States and Canada. Cancer M6(12):2736-27^0. Smither, W.J. 1979. Surveillance of high-risk groups--a survey of asbestos workers:. The present position in the United Kingdom. Annals New York Acad. Sciences 330:525-532. Thorton, J. 1981. Personal Communication. (Industrial Hygienist, Newport News Shipyard). Wagner, J.C. 1965. The sequelae of exposure to asbestos dust. Annals New York Acad. Sciences 132(1):691. Weston, R.P., A.R. Daly, A.J. Zupko and J.L. Hebb. 1976. Technological feasibility and economic impact of OSHA proposed revision to the asbestos standard. Prepared for Asbestos Information Association of North America, Washington, DC. APC 003668 Year 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 I960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 Total 8 9 14 12 8 11 20 21 14 18 21 22 18 31 24 22 29 36 29 34 26 33 58 42 35 45 54 55' Table 1 Deaths from Asbestosls United States 1950-77 by Sex and Race White Male Female 6 9 12 9 7 10 16 17 12 17 19 17 10 23 21 18 26 32 25 29 21 26 54 40 30 42 46 49 1 - 2 - 1 1 3 1 1 1 - 4 - 3 2 2 3 3 3 3 1 3 2 - 3 2 1 1 Male 1 - - 1 - -- 1 3 -- - 2 1 7 4 1 2 -- 1 1 2 4 4 2 2 2 1 7 5 Other Female -- - 2 -- 1 -- - 1 1 - APC003669 CM . Table 2 Numbers of Asbestos Products Workers and Asbestos Insulators, 1947-76, Year 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 I960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 . 1971 1972 1973 1974 1975 1976 Workers Employed by Asbestos Products (SIC 3292) 21,600 22,200 22,000 23,700 22,800 22,900 21,300 22,800 22,400 2*,700 21,800 . 19,500 20,400 21,000 22,700 21,300 21,500 22,200 18,900 18,900 21,000 21,300 21,000 17,300 16,600 Annual Average Membership in Union 6,000 . 9,000 10,000 10,000 13,700 13,700 10,000 10,000 12,000 12,000 14,000 14,000 12,500 12,500 17,000 17,000 18,800 18,800 18,300 18,300 Asbestos and Insulation Workers in US Census^l 15,500 20,000 25,700 iSourcc (1) Annual Census of Manufacturers US Department of Commerce (2) Directory of Labor Unions in the US, US Dept, of Labor (3) US Census of Population,. US Bureau of the Census APC 003670 Table 3 Estimated Cancer Deaths Which Will be Caused by Asbestos Exposure Over the Next 20-30 Years Exposure Group and Cause of Death Number Equivalent Number o: With Exposures Exposure Level Deaths Alive Today (f/cc) Per Ye?" Occupational Exposure: Asbestos Lung Cancer Insulation and Primary Asbestos 80,000 Products Workers * Secondary Asbestos Products Workers 5*0,000 8-12 * 530 900 World War II Shipyard Workers 1,500,000 Post WW II Shipyard Workers 285,000 Auto Mechanics and Garage Workers All other exposed workers 1,700,000 3*500,000 . Total 7,605,000 Other Asbestos Cancers Mesotheliomas caused by occupa tional exposure to asbestos --. 2 165 1 256 .3 212 .3 *38 2,501 1,250 333 Total extra cancer deaths per year *,08* Non-Occupational Exposure: . Asbestos Lung Cancer Mesothelioma 225,000,000 225,000,000 28 333 APC 003671 FROM JAMES E. HINES INGOT CASTING DIVISION ALCOA TECHNICAL CENTER - TO DISTRIBUTION MARIO J. CAPRIO PURCHASING DEPARTMENT PITTSBURGH OFFICE - 19 1979 OCTOBER 31 RE: MOLTEN METAL MARINITE USAGE Tabulated in Table I is the amount of 1219 x 2438-mm (4 x 8-ft) asbestos-containing Molten Metal Marinite sheets reportedly being purchased at each Alcoa ingot plant per year. Although most plants have attempted to reduce their usage of asbestos, there is still a substantial quantity used. The asbestos problem from a health hazard and from the additional costs to Alcoa to comply with OSHA Standards has not diminished. This fact together with Johns-Manvilie's objective to stop production of Marinite products containing asbestos by the end of 1980 should motivate all plants to make a concentrated effort to evaluate the more promising asbestos-free candidates mentioned below. To date two products, Marinite I (Johns-Manville) and Pyrotherm B-2 (Pyrotek, Inc.), have been identified by both Alcoa Laboratories and limited plant trials as promising substitutes for regular grade, asbestos Marinite. Marinite I in the as-received form can be used only in non-molten metal contact areas (i.e., trough covers). However, with a simple preheat to- approximately 149C (300F) to remove atmospheric moisture, it can be used as distributors or floats. An experimental heat treatment to 290C (550F) has been scheduled with Johns-Manville. At this exposure temperature, the board has provided good results as basins, troughing, feedboards, and dams. Large plant trials are scheduled initially at Massena, Tennessee and Warrick. Pyrotherm B-2, on the other hand, is supplied in the heat treated condition and can be used as a direct MM Marinite substitute. Pyrotek locations stocking this board are listed in Table III. In Table II are the trial amounts of 25.4-mm (1-inch) and 50.8-mm (2-inch) sheets requested by the plants, along with the product suggested for evaluation. Some plants have already made these substitutes. They are indicated by asterisks. ALCOA 4 APC003672 TABLE I MOLTEN METAL MARINITE USAGE BY PLANT* Badin Davenport Lafayette Massena Rockdale Tennessee Vancouver Vernon Warrick Board Grade ctnd Size Regular Grade____________ 12.7 mm (0.5 in) 25.4 mm 50.8 mm (1 inch) (2 inch) sr Header Grade 25.4 ran (1 inch) 50 /boo 100 ^yoo 50 60 /9ie - - 30 ?6o -100 headers 5 3-lo - 78 178 SL 9C 358 // - 225 150 /y Vo* <j c CO 300 - 100 -- - 12 12 3iS - -50 headers - 120 3 Yo 240 /f3Co 1600 fl * ^ Total 12 936 720 2050 ^ JOf WK J (y (? ' l Wenatchee and Point Comfort were not included in this survey. l6 c PRIVILEGED. AND iv. t L-' V I: h ai APC 003673 TABLE II TRIAL QUANTITIES OF ASBESTOS-FREE BOARD REQUESTED Boards 25.4 mm (1 inch) 50.8 mm (2 inch) Badin Davenport Massena Rockdale Tennessee Vancouver Vernon Warrick 50 Marinite I or Pyrotherm B-2 10 Marinite I 15 Marinite I or Pyrotherm B-2 178 Pyrotherm B-2 5 Pyrotherm B-2 3 Marinite I 12 Marinite I* 120 Pyrotherm B-2 100 Pyrotherm B-2 15 Marinite I 225 Pyrotherm B-2 5 Marinite I 240 Marinite I or Pyrotherm B-2* *Substitutions already in progress APC 003674 TABLE III PYROTEK, INC. LOCATIONS Plant Spokane, HA Carlisle, PA Trenton, IN Address E. 9601 Montgomery Avenue Spokane, HA 99206 Phone: (501) 926-6211 Box 77, RD 1, Claremont Road Carlisle, PA 17013 Phone: (717) 249-2075 Kellwood Drive Trenton, IN 38382 Phone: (901) 855-0104 APC 003675 DISTRIBUTION 1979 OCTOBER 31 Page 2 It is hoped that each plant makes known their testing so that information can be disseminated to the other locations and the level of activity can be monitored. A frequent updating of the Molten Metal Marinite situation and each plant's progress toward eliminating asbestos will be made. If a plant does not have the recommended asbestos-free candidates bn hand or on. order, Mr. M. J. Caprio in Pittsburgh Purchasing should be contacted immediately. Any questions, comments, or additions to the attached would be appreciated. Only through a cooperative effort can asbestos be replaced. JAMES E. HINES JEH/MJC:gih ' / Attachments - 3 (Distribution - Page 3) MARIO J. CAPRIO P APC003676 DISTRIBUTION 1979 OCTOBER 31 Page 3 PLANT METALLURGICAL ENGINEERS C. T. Barger, Jr. - Badln Wks. T. F. Arnold - Cleveland Wks. A. F. Maloit - Corona Wks. R. J. Stokwisz - Davenport Wks. D. 0. Collins - Lafayette Wks. D. E. Scott - Lafayette Wks. M. Scherbak - Massena Oprs. G. G. Owens - Rockdale Wks. G. K. Reichelt - Tennessee Oprs. J. M. Ekenes - Vancouver Oprs. W. C. Harvey - Vernon Wks. D. Fleener - Warrick Oprs. J. B. Gorss - Warrick Oprs. P. C. Scheble - Warrick Oprs. J. E. Gunn - Wenatchee Wks. PLANT PURCHASING H. A. Barton - Badln Wks. T. G. Poliak - Cleveland Wks. Shirley Price - Corona Wks. R. W. Murphy - Davenport Wks. R. C. Miessler - Lafayette Wks. E. R. Werner * Massena Oprs. J. R. Fry - Rockdale Wks. J. Taylor - Rockdale Wks. W. S. Zuber - Tennessee Oprs. M. D. Wooden - Vancouver Oprs. J. Heron - Vernon Wks. T. A. Innes - Warrick Oprs. D. Lutz - Warrick Oprs. INFORMATION COPIES TO: PLANT SUPERINTENDENTS J. N. Rumble - Badln Wks. M. A. Gambill - Davenport Wks. W. K. Dalton - Lafayette Wks. G. L. McCullough - Massena Oprs. G. L. Williams - Pt. Comfort Wks. T. J. Randall - Rockdale Wks. D. W. Freeman - Tennessee Oprs.-S D, F. Simonic - Tennessee Oprs.-N D. E. Luckett - Vancouver Oprs. M. L. Redhair - Vernon Wks. A. Pearson - Warrick Oprs. R. S. Grundhoefer - Warrick Oprs. (Can Reclamation) E. T. Vanderheyden - Wentachee Wks. C. J. Cox - 3 WPH J. W. Mclntee - 3 WPH H. G. Reavis - AB 23 E. L. Rooy - AB 23 H. G. Sakoian - AB 7 A. J. Sartschev - 3 WPH D. L. Schaeffer - AB 23 J. Damiano - ATC, C T. W. Lee - ATC, D R. E. Spear - ATC, C J. R. Stemler - ATC, C R. E. Miller/R. G. LaBar - ATC, B. APC 009677