Document 2NQ2zVvyzVkwN52p813Bpxywb

UtU *3 is/t> PROGRESS REPORTS FROM THE INSULATION INOUSTRY HYGIENE RESEARCH PROGRAM ; Irvine J. MM, IIJX, huniw Mnetw Vot. 7 No. 9 and 4 .. Winter 1975 0046626 New Asbestos Standard Proposed Cancer Risk Specifically Considered On October 9,1975, the Department of Labor proposed a new standard for occupational exposure to asbestos. The proposed standard would, among other things, lower the permissible asbestos exposure to 500,000 fibers per cubic meter of air (0.5 asbestos fibers per cubic centimeter) for an eight-hour, time-weighted average exposure, and likewise reduce the petmissible ceiling exposure to five million asbestos fibers per cubic meter (S f/m3) for any period not exceeding IS minutes. 'Hie pro posal would reduce to one-tenth the current U.S. time-weighted average exposure standard of 5 f/ml. A reduc tion to 2 #ml on July 1,1976 is already mandated in the current standard. Special Provisionsfar Construction The standard, as revised, would apply to all workplaces where occupa tional exposure to asbestos occurs, but would exclude the construction indus try at this time. However, the Occupa tional Safety and Health Administra tion (OSHA) plans to soon put forth special regulations for this segment of the asbestos industry. In the proposed rules published by the Secretary of Labor, it is stated that, "It is OSHA's intention to develop and propose a separate revision to the exist ing asbestos standard for the construc tion industry. Approximately threefourths of all asbestos products in 1972 were used in the construction industry. In addition, the uniqueness of the con struction industry itself (viz., the mul tiplicity of non-fixed workplaces, and die utilization of highly transient wort forces) strongly suggests separate treatment. These structural differences were reflected in the 17-18 September 1975 deliberations of the OSHA Ad visory Committee on Construction Safety and Health. . "Although OSHA believes that health hazards faced by/employees in the construction industry with regard to occupational exposure to asbestos are similar to those faced by their counter parts in other covered employments, OSHA recognizes dial alternative ad ministrative and engineering controls may be more appropriate and feasible forthe construction industry. Therefore OSHA intends to consult with the Con struction Advisory Committee in order to further explore such alternatives. Upon publication of the proposal to re vise the existing asbestos standard for the construction industry, OSHA will consider the possibility ofconsolidated hearings on that proposal and the pro posal contained herein for all other cov ered employments." This recognition that the construc tion industry is unique is highly desira ble. Earlier data on the effectiveness of monitoring in the construction industry (see Insulation Hygiene Progress Re ports, Summer 1973), have shown that few dust counts are ever taken in this segment of the industry. Thus, spec ification of procedures is of much greater importance here. Individual workers must be able to judge whether or not they are working in a safe envi ronment on the basis of materials and methods rather than dust epunts. As much of insulation is now asbestos-free, work practices for in stallation of new material can be de veloped that would lead to a timeweighted average exposure less than that proposed in the new standard. With care, even rip-out can be done safely, but special precautions must be taken. Wetting techniques have now bees de veloped that would allow removal of asbestos to be accomplished within the proposed regulations. Millions of Workers Exposed In the preamble to the standard, OSHA estimates that millions of work ers are occupationally exposed to asbes tos. They state, "An estimated 50,000 workers are involved in the manufac ture of asbestos-containing products. However, this figure does not include secondary manufacture of products which contain asbestos, such as electri cal or thermal insulation, or products which include previously manufactured components containing asbestos. "There are approximately 40,000 field insulation workers in the United States who are exposed to asbestos dust. The activities of these workers is estimated to cause secondary exposures to approximately three to five million other buildings construction and ship yard workers. However, since the dust exposure to the individual worker is extremely variable, and the number of asbestos workers at any one location is small, the primary and secondary as bestos dust exposures to all workers have never been satisfactorily esti mated." Cancer-producing Substance The impetus behind the new pro posal is the acknowledgement by OSHA of the cancer-producing prop erties of asbestos. The current United States standard was based to a large extent on one developed earlier in Great Britain and pul into effect in 1970. That standard, in turn, was designed solely to protect against lung scarring (asbestosis). Cancer was recognized as an oc cupational hazard from exposure to as bestos but foe British committee de veloping their standard stated that since a quantitative relationship between as bestos exposure and cancerrisk was not known, it was not possible at that time to specify an air concentration which was known to be free of risk in this respect. It was hoped by the British, and by the United States agencies, that application of control measures that would protect against asbestosis would Continued on page 3 e e i*> oo Insulation Hygiene Progress Reports Vol. 7 No. 3 and 4 Winter 1975 from the insulation Industry Hygiene Research Pro gram Editor; W. J. Nicholson, Ph.D., published at the Environmental Sciences Laboratory (Irving). SelikofT. M.D.. Director). Mount Sinai School of Medicine of the City University of New York, N.Y. 10029 Advisory Council ef IIHRP Irving ). Selikoff, M.D., Program Director and Chairman E. Cuyler Hammond, Sc.D., Vice President, American Cancer Society, New York, N.Y. Andrew Haas, General President. Intemarional Association of Heal and Frost Insulators and As bestos Workers. Washington, D.C. PURPOSES OF THE INSULATION INDUSTRY HYGIENE RESEARCH PROGRAM 1. To develop improved meth ods for minimizing exposure of insulation workers to dusts and fumes encountered in their work. 2. To disseminate knowledge of these improved methods of dust control wherever they may be applied advantageously and to offer cooperation, advice and as sistance toward their universal adoption. Asbestos Risk Exists from Use'of Taping Compounds In spite of the introduction of _ The Environmental Sciences Lab asbestos-free insulation materials and oratory took air samples at selected job the existing bans on the use of asbes sites in New York City while tapers tos-containing spray fireproofing, a were at work. Personal samples taken serious asbestos hazard remains in the during pole sanding ranged from 1.2 construction industry, with members of fibers per milliliter (f/ml) to 19.3 f/ml; the Painters Brotherhood of the Build in an adjacent room, at a distance of 23 ing and Construction Trades Depart feet from the sander, a level of 8.8 f/ml ^ ment being at greatest risk. Wallboard was found. Levels for hand sanding__ ^ finishing compounds and spackk have tanged from 1.3 to 16.9 f/ml in the __ been found to contain significant breathing zone of the workers, and aZI amounts of chrysotile asbestos, which high of 7.1 f/ml was obtained in anTL is released into the air as dust either adjacent room, at a distance of 13 feet. during the dry mixing of these com During dry mixing, a breathing zone pounds or during sanding. sample was found to contain 59 f/ml, Drywall taping compounds came though after a 15-minute lapse the level ^ into widespread use shortly after World went down to 0.5 f/ml. War II. Until fairly recently, most of The sweeping of floors after sanding the material used was mixed at the con was also found to stir up considerable struction site, raising large clouds of quantities of settled dust. Thirty-five dust. In the past few years, many con minutes after sweeping at the site ofthe tractors have switched to premixed sanding, a fiber concentration of 26.4 compounds, thereby eliminating one f/ml was obtained. The current U.S. major source of asbestos dust. This standard in industry is an average not to practice, though, depends entirely on exceed 5 f/ml, mandated to go to 2 f/ml the contractor and what he supplies; in July, 1976. The Department of several tapers interviewed recently by Labor has recently initiated procedures Mount Sinai personnel said they still to have the standard lowered to 0.5 had occasion to use the dry-mix brands. f/ml. Sanding can be Dangerous The results of this sampling, espe cially when contrasted with the current The problem that remains, even standard in industry, emphasize the im when ready-mixed compounds are portance of both respiratory protection used, is that of the dust produced when and careful cleanup in order to reduce the dried compound is sanded, prior to the ride of inhaling asbestos fibers. A painting. In some areas of the country, respirator should be worn by sanders tapers, or their apprentices, stay and do their own sanding; in others, die paint and by any other workers who must be in adjacent areas while this work is in ers are left to finish the job, often sand progress. If possible, other workers ing while other men are working in the should wait to allow the dust to settle same room. Sanding is done either by and be removed before proceeding with hand or with a pole. Continued on page 4 Mixing of asbestos containing speckle material. Dust concentrations during this process can ex- ceed the current asbestos standard by more than ten times. DOW 02134  New Information on Health Effects Reviewed Continuedfrom page I also protect against the various asbestos cancers. Important new information has been forthcoming subsequent to the promul gation of the current U.S. standard. This has included data obtained by Drs. Irving J. Selikoff and E. Cuyler Ham mond on the mortality experience of all insulation workers in the United States. This large research project showed un equivocally the high risk oflung cancer and mesothelioma experienced by as bestos workers, and in addition, dem onstrated that gastro-intestinal cancer was also increased in incidence among asbestos workers. As data from this large study were reviewed, it was sug gested that the risk of developing cancer of the larynx, oropharynx, or esophagus was also increased from as bestos exposure. Research with the In ternational Association of Heat and Frost Insulators and Asbestos Workers was quoted many tiroes by the Depart ment of Labor. Further studies ofother large groups of workers occupationally exposed to asbestos in factory employ ment or mining and milling also indi cated excess carcinogenic risk. New Information The Department of Labor particu larly noted information forthcoming from the British Textile mill whose workers' health experience served as basis for the current British standard. "Of significant importance, new data have recently been made available con cerning the cancerrisk ofworkers at the textile mill reviewed for the British standard, including those workers first employed after 1933. It was found that there was excess mortality from lung cancer among those workers who en tered scheduled areas aftec I January 1933. There was clear evidence of some excess of lung cancer and res piratory deaths among those first ex posed between 1933 and 1950. Equally important was the finding that there still appears to be an excess ofdeaths due to lung cancer after 15 or more years' ex posure even among those first exposed in 1951 and subsequently. Indeed, it is known that mesothelioma deaths have occurred among tbe specific group of 290 workers whose experience prior to 1966 had led to the development of the current standard, as detailed above." Additionally, they noted the increase occurrence of mesothelioma in workers only indirectly exposed to asbestos. where it appears that average exposure levels would often be considerably less than the projected 2 i/ml standard. Shipbuilding Data Important "Of considerable industrial impor tance has been the recent description of asbestos disease among shipbuilding and ship repair workers, few of whom actually work with asbestos, but many of whom were, in the past, inadver tently exposed to the asbestos dust re sulting from tbe use of asbestos prod ucts by a relatively few of their work mates. In 1968, Harries of the Royal Navy reported cases of mesothelioma among shipyard workers at the Royal Navy dockyard in Devonport, in trades which did not directly involve workers exposures asbestos, but in which there had been occasional opportunity for exposure merely by virtue of working in the same areas. This original finding has been widely confirmed and numer ous cases of mesothelioma have since been reported in former shipyard work ers. Studies of populations of current shipyard workers have shown much radiological evidence of asbestos ab normalities among workers in trades only indirectly exposed to asbestos in the yards." "Further, evidence has indicated that asbestos also acts as a lung car cinogen at levels much below those which will produce asbestosis. Two surveys of shipyard workers who had x-ray evidence of pleural plaques, but generally not of pulmonary fibrosis, showed a 2.5-fold excess risk of death from lung cancer and high risk of mesothelioma." Finally, a recent study by NIOSH was reviewed which showed that the mortality experience of underground metal miners exposed to asbestiform minerals produced a threefold in creased risk ofbronchogenic carcinoma in workers. Fiber concentrations in the mine average 0.24 f/ml. In discussing considerations applic able to standards for carcinogens, OSHA stated that, "In the case of as bestos, we are dealing with a substance that poses a range of health risks to the working population. These include the threat of cancer, as well as asbestosis. In considering the controversial issue of carcinogenicity, OSHA is relying upon not only the new data reviewed above, but the leading scientific principles and options believed to reflect the research conclusions of international cancer ex perts, which were developed since or not known to OSHA at the time that the original standard was promulgated. "A. THE LATENCY CARCI NOGENIC EFFECTS "In humans, the latency period for chemical carcinogens may well extend between 20 to 40 or more years. Analogous periods exist for test ani mals. This means that the disease may undergo a long development before a tumor is actually detected. At that point, it has reached a stage where re moval of die worker from the work place may be of no avail and where treatment may be extremely difficult, if not futile. Prudent policy would there fore seem to indicate that every reason able measure should be taken to elimi nate human exposure to chemical com pounds as soon as their carcinogenic nature is identified. "B. VARIABILITY IN INDIVID UAL SUSCEPTIBILITY IN RELA TION TO THE CONCEPT OF A THRESHOLD "Cancer development may be influ enced by such factors as the differing susceptibility of various body organs. In animal studies, it has been found that individual variability in a response to carcinogens is great depending upon factors such as age, sex, hormonal status, diet, and genetic factors. Thus, in the working population, certain groups, such as those already biologi cally compromised, may be more sus ceptible than other groups. "C. A `THRESHOLD' LIMIT "Because of the variability of indi vidual response to carcinogens and other factors, the concept of a no effect or threshold level may have little real significance on the basis of existing knowledge. While some level, below which exposure to a carcinogen does riot cause cancer, may conceivably exist for any one individual, other indi viduals in die working population may have cancer induced by doses so low as to be effectively zero. This is not to say that researchers will never find a threshold level for a carcinogenic sub stance, but it does mean that the threshold concept for carcinogens is. at present, more a matter of responsible regulatory policy than a precise, scien tific determination. "These theoretical concepts have a Continued on page 4 CO o o oo cn ro CD to (*) <\ C 3 C a Sanding of Spackle Material Should be Limited Continuedfrom page 2 their own trades. The area should be cleaned, preferably with a vacuum, as soon as the dust has settled. If no vac uum is available, the floor should be dampened prior to sweeping, and the sweeper should wear a mask. Health Effects Seen Simply because sanding is only a small part ofthis construction activity is no reason to minimize the importance of the problem. Although exposure du ration may be short, the cumulative ef fect ofrepeated short-term exposures to measurable concentrations of asbestos fibers can be serious. In the course of a medical study of 69 drywall tapers be longing to Local 1974 of the Drywall Tapers and Painters of Greater New York, two-thirds of whom had had an exposure often years duration or longer and 61 of whom were smokers or ex smokers, X-ray abnormalities charac teristic ofasbestos exposure were found in 37 out of 63 films There is a dose similarity between these findings and those among insulators. At least one brand of commercial wallboard finishing compound is cur rently available containing no asbestos. It is likely that, as the negative aspects of asbestos-containing compounds be come more widely known, other man ufacturers will develop new formula tions that are free of asbestos. Until then, only premixed materials should be used and the sanding ofdry material eliminated or reduced as much as pos sible. Comments Solicited on Proposal ' Continuedfrom page 3 - bearingj^n foe asbestos issue, perticu-: larly as m foe question ofthe existence, or nonexistence, of a threshold level of carcinogenic effect. A no effect level theoretically may exist, but it has not been demonstrated. "In previous rulemaking proceed ings, OSHA has considered these is sues and determined that in the absence of evidence to establish a safe level on foe basis of present knowledge, em ployee exposure must be reduced as low as feasible.** In a further discussion of the major provisions of the proposed standard, OSHA explicitly recognized that, "since the promulgation of the current standard, several distinguished indi viduals and many agencies, both public and private, have made valuable con tributions to foe field of toxic sub stances generally, and asbestos spe cifically. "Exposure Levels. Recently, the National Institute for Occupational Safety and Health (NIOSH) has in formed OSHA that it is currently re viewing data which may provide signif icant information with respect to the margin of safety afforded by foe exist ing asbestos exposure limits. In a memorandum dated 29 September 1975 to the Deputy Assistant Secretary of Labor for OSHA, foe Director of NIOSH stated: Multiple and consistent epidemio logical studies leave virtually no doubt that asbestos is carcinogenic to man. "OSHA also believes sufficient medical and scientific evidence has now been accumulated to warrant the designation of asbestos as a human car cinogen. Therefore, it is incumbent upon OSHA to propose the establish ment of safeguards to protect foe lives of affected workers. No Safe Level for a Carcinogen "OSHA deems it appropriate to propose that the 8-hour exposure limit (TWA) be lowered to 500,000 asbestos fibers per cubic meter (0.5 asbestos fib ers per cubic centimeter), and that the ceiling exposure limit be 5,000,000 as bestos fibers per cubic meter (5 asbes tos fibers per cubic centimeter) for any. period up to 15 minutes. OSHA recog nizes that there is no assurance ofa safe exposure for a substance with known carcinogenic property, in this case as bestos, and thus there should be no de tectable concentrations. However, the Act requires that foe Secretary establish standards to extent feasible, and there fore the Secretary must take into con sideration technological and economic factors. "OSHA believes that H may be ap propriate to postpone the effective date of foe proposed exposure level because offoe existence ofproblems offeasibil- (/> ity ofa technological and economic na- --* ture. OSHA expressly invites com- q ments on this issue, including comment 0 on foe appropriateness of a phased .pschedule for compliance with any newg^ exposure level, based on such feasibil- ^ ity factors. In this respect, OSHA particularly invites comments on the struc- ^ ture of foe asbestos industry generally including factors distinguishing par ticular sub-industries in terms of meth ods of asbestos use and capabilities of compliance/* The deadline for submission of comments on the proposed regulations is December 8, 1975. Additional provisions in the proposal put forth by OSHA would "extend the retention period for'medical and monitoringrecordsto forty years, or for the duration ofemployment plus twenty years, whichever is longer, provide procedures for the transfer of medical and monitoring records of certain formeremployers; require specific min imum data on medical and monitoring records; revise the procedures for initial and subsequent monitoring; modify foe definitions of asbestos and asbestos fiber; add provisions for employee hygiene, information and training; re vise and update the requirements for respirators, and warning signs and labels; and establish a time parameter for sampling ceiling concentrations. In addition, the proposal will suggest work practices to be followed for cer tain operations and processes involving asbestos.** Of particular importance is a pro posal that would add sputum cytology as a diagnostic test. Tltis is proposed only for workers who are forty-five years old, or who have been employed in the asbestos trades for ten years or more. Here, analysis of cells coughed up from the lung may be useful in indi cating the early stages oflung cancer, at a point where more successful treat ment can be accomplished. This proce dure was recently proposed to NIOSH by President Haas for all members of the IAHFIAW and is being considered by foe Institute. DOU 02136