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0 -r THE MOUNT SINAI MEDICAL CENTER ONE GUSTAVE L LEVY PUCE NEW YORK. N Y. 10029 Mount Sinai School ofMedicine The Mount Sinai Hospital December 7, 1*84 John A. Moore, DVM Aaalatast Administrator for Pesticides and Tonic Substances Bnuironmtntol Scitnctt Laboratory Om m C----t--mmmgt Bo----o- ie Scitn'ctt BuBBing W . i v to Boot 103 Snarl Kic Vof*. Nw Ye* 10029 jg jgCQ2> omits .1 Dear Dr. Moorat It haa baan Bade known to me that my written remarks of October II, 1984 concerning the Batural Xaaourcca Defanaa Council's Petition for a "Prohibition on Continued Dae of Aabaatoa in Automobile Brakes" will enter, with other documentation, into the rule-making docket along with the original petition. Z am therefore requesting that this latter be aubstituted as a formal critique. My concerns regarding the petition are many, essentially focusing on lack of Insight and on an unscbolarly approach to the problem - The BBDC claims that both epidemiological and pathological reports "have shown only recently that asbestos is one of the largest single causes of environmental human eancer in the United States." This statement does not accurately reflect the literature. In support of this statement the petition cites HHS Secretary Califano who reported that approximately 171 of American eancer deaths over the next several deeades will be "linked" to a'sbestos. There are approximately five hundred thousand cancer deaths per year in the United States which would roughly translate into 85,000 cancer deaths per year "linked to asbestos." Xmaediately following this statement is an attribution to Bieholson and co-workers who have estimated that eancer deaths in the United States from asbestos will number some 6,500 to 10,000 per year over the next 20 years. The authors of this document fail to reconcile this order of magni tude difference in these figures; fail to resolve the proportion of exeess cancers attributable to workplace exposures; have not considered that if 8,500 cancer deaths will occur among 10-15 million "exposed" workers in different occupational settings, 85 thousand asbestos "linked" deaths means that everyone in the general population is at the same level of risk. It seems farfetched; - ij their discussion of mesothelioma and lung eaneer, the BBDC authors use data from studies of Insulation workers in their deserip- UCC 004206 C2S76 . tJohn A. Moore, DVH 2. Dtetaber 7, 1984 tlon of lacruitd risk of ubutoi dlwmi in ixpowd populations. The nature of the fiber exposure, fiber type, fiber dimensionality and fiber concentration are significantly different when compared to workers maintaining and repairing brake pads. Data for insula tion workers may have little bearing for brake workers, these _ data are uncritically accepted as data applicable for all workers '"deposed to any variety of asbestos fibert the assertion that all asbestos fiber types are cardnotenlc in humans is correct. lowever, not all fiber types produce human mesothelioma (bb --othaH *v baan wporfrf wniipf humane exposed to anthophylllte fiber in the workplace) and not all of the asbestos fiber types produce the same attack rates for broncho genic carcinoma. While it is true that the three major varieties of asbestos used in the United States induce both types of malignant tumors in experimental animals, industrial manipulation may alter outcome; - There is an attribution to a study conducted by ay colleagues here in the tnvlronmental Sciences Laboratory which revealed excess cancer mortality "in workers with short-term exposure--one month or less of employment in an asbestos plant." This 'citation appears at the end of a paragraph which states that "People living in the area of asbestos mines, mills, factories and even shipyards and family members of asbestos workers have become victims of mesothelioma despite what we would be considered light exposure to the dust." The asbestos plant in Paterson, Mew Jersey is believed, by many (including Seidman of the American Caneer Society) to have had workplace exposures approaching lOOf/ml. Vleholeon occa sionally uses a figure of 35, I have used a figure of 50 but It is generally conceded the exposure levels were very high Indeed. One month's exposure during the second World War translates into a-500-l,000f/ml exposure day (10-hour shifts during the second World War). Using a 20-day work month this computes to a 10,00020,000f/ml exposure month. This would correspond to approximately a 2-5 year exposure in the occupational setting at the present 2f/ml level. Vo one would consider this a "trivial" exposure. Vo one would consider this a "bystander" or "environmental" exposure; - Zn the very next paragraph, on page 8 of the petition, the work of Barries, carried out in the Devonport shipyards of Great Britain, is used to support their argument that mesothelioma may occur from "bystander" exposures. Barries and colleagues shoved that the tearing out of asbestos fiber on shipboard results in aerosols which may approach l,000f/ml in the immediate environment! Fiber measurements made during tear-out operations, aboard ship, haveshown tens of ifml of air in areas removed from the actual site of rip-out. Again, this is included to support the argument of the petitioners that "indirect occupational exposure" was sufficient to produce mesothelioma many years later. These indirect measurments are considerably greater than those encountered in most workplaces today. Additionally, the fib^r types encountered in 1 UCC 004207 C2877 Joha A. Moore, DVM 3 Stcnbtr 7, 1984 the Paterson insulation plant was amosite and the fiber encountered bp larriat in the Devonport shipyard was predominantly erocidolita. The mesothelioma frequency for both these fiber types exceeds those reported for ehrysotile in every study the world over. Vs are dealing with mesothelioma'risk for different fiber types. Although chrysotile asbestos does produce human mesothelioma one I cannot use the experience-of workers exposed to erocidolita and asmslte as a "measure of risk for chrysotile exposure;" * Although asbestos fiber released from automobile brakes may increase the asbestos levels encountered in .urban air the report of a mesothe lioma in a toll collector is not evidence of an etiological associa tion; - Z will support the contention of the petitioners that there are operations encountered during brake maintenance and repair which release "dangerous levels of asbestos during brake servicing;" - The general case for risk to non-occupationally exposed persons is based on risk assessment models. For example, Michoison (1983) has provided the Environmental Protection Agency with a document entitled "Asbestos Eealth tffects Update." Using this model a general scenario is generated for both lung cancer and mesothelioma and extrapolations are made concerning risk to populations for which no exposure data exist. Sleven studies provide lung cancer data whereas four studies provide the mesothelioma data base. The lung cancer etudies provide fractional increases of lung cancer risk per unit of exposure but these fractional risks vary consider ably depending on fiber type and industry, to it is with the mesothelioma data set which is based on a number of fiber types integrated to yield a single r.isk model. The question to be raised is whether data for croeldollte, amosite and mixed fiber types (the insulation worker data) may be used for ehrysotile. This, coupled with the relatively poor workplace fiber measurements, yields a model which may be used only in its broadest context. These shortcomings ware raised in a recent KtC document (1984) where ranges of risk were provided rather than a single value. Again, the mesothelioma data (1 stress mesothelioma because segments of the population will live long and-this will be the important disease on the basis of time) is based on insulation workers (mixed fiber), chrysotile textiles, amosite insulation, and asbestos cement product manufacture. The lowest values exist for ehrysotile exposure in textile plants. Therefore, all of the asbestos deaths projected into the future are based on risk assessment for mixed fibers in a range of circumstances. The variance associated with these projections are large. The numbers of deaths attributable to asbestos brake pad maintenance amounts to some 500 per year \over the next several decades. This value may be lower or even greater than given. Ve simply do not know; - The only pleural mesothelioma described in a brake repair worker, in which only chrysotile asbestos fiber was observed in the pulmon- UCC 004208 .c John A. Moor*, SVM December 7, 1984 ary tliiuu, vm reported by myself. Z believe thie working populetlon to be at risk bat I also believe this risk to be less than encountered with other fiber types la other work eavlroaoeats) Share are the data to show that substitute friction product materials are "safe"? Shat happens to e.g., araaid fiber when sheared froa a brake surface?) " Why is "sintered ^etal" compositions considered safe? Sintered hard aetal materials are now implicated in pulmonary disease (hardmetal disease). I agree with the petitioners that there are many instances where brake maintenance and repair subjects workers to asbestos fiber exposure which increases their neoplastic risk. There is no question that this occurs and that the risk is measurable. X siailarly believe that there arc no data to support that such risk exists for the general population. Exposure to the general population aay occur and that the control of asbestos eaisslons should be instituted. Bovever, we have no data to support the contention that it represents a "public health haxard." Z believe it would be prudent to prevent such exposures froa occurring to the general population even though there are no data to support that such exposures are hasardous. The federal courts have noted that one aay rely on "general data" in aaklng certain decisions. Therefore', if this petition is to be considered as a "general approach" to the asbestos problem then, presumably, the Environmental Protection Agency will base its decision on courtroom lav. As it now stands, one can only appeal for the decision to be based on the concept of "prudence" rather than sclcnec. The decision should be made on the social basis and not a pseudo-scientific one. This issue is a very important one and should not be approached in an upsebolarly fashion. My strongest objections focus on the misuse of data and the uncritical use of these data in supporting certain contentions. Zt is a form of quasi science which we, as environmental scientists, cannot afford or allow o go unchallenged as it reflects upon all of us and our work. AMLt jm Arthur M. Longer, Pi\D.H Associate Professor of Mineralogy. Associate Director, Environmental Sciences Laboratory UCC 004209 LZQ73