Document QNQDxp2xkLMedzxwYK21Qnv8

VINYL CHLORIDE AND OCCUPATIONAL HEALTH In January 1974 the B.F. Goodrich Company announced publicly that the plant physician at its Louisville, Kentucky, polyvinyl chloride (PVC) resin plant had identified three cases of angiosarcoma of the liver, an extremely rar* type of cancer, among long-term plant employees. The company said it suspected that vinyl chloride monomer (VCM>, th^ gesaojis industrial chemical * -i 'i ^ -, from which PVC resin is produced, might be implicated in the three deaths. K yrty . '" *'" ' ->t;: m The announcement by - * of the - most intensive health. It Wap American public in literally hu^^ radio shows* medic eveh became v ' It the last in peri . af--T wij OCC 1323 2- - The "epidemic" of angiosarcoma cases predicted by some individuals in 1974 has not occurred. Over the past 16 years there have been a total of 23 deaths from angiosarcoma in six U.S. plants and approximately 48 in other countries. Industry opposition to the vinyl chloride standards as originally proposed by the Occupational Safety and Health Administration (OSHA) was based on technical infeasi bility, the vagueness of the "no detectable level" proposal, and an over-reliance on animal data. OSHA changed the standards to make them more feasible and subsequent studies have proven the industry's contention that experimental animals are far more susceptible to VCM than are human beings. Based on a wide variety of epidemiological studies, the current OSHA standard of 1 part per million in air provides more than an ample* margin: :o safety for industry workers. '* . -.-i ' T""1 According to experts from Harvard University and the university of Texas, the single ntudy elleging an excess of stillbirths and mAacarriagss among ............. he*ii "` workers is - * inadequate ,*"misleed iir .* 4 Background m- in4u**mjP chlorine. to h*vp*^~ professio: OCC 1324 3- - presented flammability and explosion risk potential. However, controls were devised for these problems. Information on possible long-term health effects of VCM exposure was admittedly scanty and incomplete during the 1940s '50s and '60s. The first inkling of a potential problem was a 1949 study of 73 workers in a Russian plastics fabricating firm. The study indicated evidence of hepatitis among the workers but concluded that this was due to exposure to a polychloro-biphenyl (PCB) plasticizer used in the factory and not to VCM. Much was made of this 3tudy by professional activists following the discovery of the vinyl chloride cancer link, but apparently no one in th -a American medical community -- governmental>* trial or private -- was aware of the. study prior to 19?4> J ` *. A 1961 .<* it long- term exposure $*iitewn tq 100 parts pe^r > but a similar lit' concern*< -T1. / ' taiEraximum CC 1325 4- - One of it3 principal functions is the promotion of standards and techniques in industrial health. Thus the standard was not an arbitrary one, but was set after professional evaluation of all available data. In 1963, the ACGIH recommend.ed a ceiling of 500 ppm for vinyl chloride. This same level was adopted in 1971 by the newly created Occupational Safety and Health Administration (OSHA). In 1966 a reversible disease of the bones of the fingers called acroosteolysis was discovered among some heavily exposed reactor cleaners. Prompt and appropriate industrial hygiene efforts by the industry quickly eliminated the problem. Strangely enough# it was the indust ;.4 . -v answer to the cause of acfooeteoIysis tat~ the di.coV.r,, * Ch for an . i it* . , ntusliy lead to X< ' IcZ... . f .... . Cancer Link Disco' I1* ")$; sponsored ' M4:, the Regina Dr. Viola'/I leading Eur Cancer Congress ih Houston in May 1970 pinpoint tation. OCC 1326 produce cancers (but not angiosarcoma) in test animals at ex tremely high levels (10,000 to 30,000 ppm) of VCM exposure. Dr. Viola's findings were subsequently published in the Journal of Cancer Research in 1971. While no notice of Dr. Viola's findings was taken by any government agency involved in worker health, the PVC industry both in the United States and in Europe began plans for more extensive animal studies at levels of exposure more likely to be encountered in actual plant situations. Epidemiological studies of plant workers were- alW' piahnedl03 " :'' 1 The European animal inhalatldh the directixtti Md&oJii '&______t and Centret Conducted under di Oncologia European 'Association rttiT sponsor be lifornia. Industrial which worm OCC 1327 6- - Because the European research had gotten underway earlier than the efforts undertaken in America, some preliminary results of Dr. Maltoni's study became available in early 1973. Accordingly, a technical delegation from the U.S. PVC industry visited Dr. Maltoni in Italy in January of that year to review the progress of his research. The American team learned that Dr. Maltoni had detected a variety of tumors in test animals at concentrations as low as 250, ppm. The American PYC industry then requested, a meeting with the National Institute^. Oca^njtional Stkfpi& Health (niosh) to call. the.ptpuilta, %V. S. governdiscussions uiosh t sOCC 132 no excess of cancer or any other disease among the workers, and (3) angiosarcoma had not yet been discovered among industry workers. The Government Acts In addition to its public announcement on January 22, 1974, regarding the three angiosarcoma deaths, B.F. Goodrich also notified officials of NIOSH as well as Kentucky state medical officers. A week later it was discovered that another former employee of the same plant had also died from angioaarcon. This resulted in. an exit^m4v% aearch by the industry througi^joid medical records of * JLtimately, ivw*t detatmln*^ that ovjsr. the past 16 vmam # total <a& IX dss^ ^pst angipsarcoma in IStoraary ^iwbioh lowered in,; Only. ~ (0V. - 1 '"-y-? ............. - '*'*. * > ' ' 'V>W8 ' EnviroiBiBenta^^sotaciion Agency (EPA) that tarsitnlnary results of the Indu trial Bio-Test Laboratories animal, exposure study showed that VCM could produce angiosarcoma in mice at 50 ppm. OCC 1329 8- - This was subsequently confirmed by Dr. Maltoni on his rat experi ments in June. On May 10, therefore, OSHA proposed a permanent worker standard which would reduce in-plant exposure to the "no detectable level" and require complete impervious suits and self- contained breathing equipment. Shortly before this, on May 7, MCA publicly announced the preliminary results of the Tabershaw-Cooper worker survey which showed that workers exposed to VCM had overall cancer death rates comparable to those of other U.S. industrial groups and lower than those of the general public. Public hearing*, up till then the largest ever held by OSHA, began in Washington6# thine 25. : The- industry** position was essentially that tile OSfSf 'proposal' v*a# uha'%al#stitf Wdause (1) it relied too Weevil^ mi sinimml date*, Wok# relevant Data developed by th Dow Chemical Company showed `no excess mortality OCC 1330 9- from any cause among long-term workers exposed to levels below 200ppm. Despite the evidence presented at the hearings, on October 1, 1974, the agency announced a permanent standard for VCM which called for reducing exposure levels to 1 ppm averaged over an eight-hour day, with peak exposure levels not to exceed 5 ppm as measured over any 15-minute period. The standard further said that, during the first year, employers were to provide respirators for employees exposed to between 1 and 25 ppm, but that it was up to the employee whether he wanted to wear it or not. At exposures above 25 ppm, wearing of respirators was mandatory. After January 1, 1976, wearing of ' ' v hi:-.......... respirators would be mandatory for all workers whenever levels ; On the other hand, regulations L* . at'' low levels of exposure that it is permissible to set "technology forcing" standards that OCC 1331 -10- may be achievable at some undetermined time in the future with technology as yet undeveloped. Because of the judicial proceedings, the implementation date for the standards was delayed until April 1, 1975. Meeting the New Standards Long before the standards went into effect, industry members had been actively seeking new means to reduce worker exposure. The industry's opposition to the "non-detectable" '>wri proposal had been based principally on the virtual technical impossibility of achieving this standard and on the impracticality of using air respirators that would be une*, uncomfortable and would inhibit workers fre* moving around o% the,job. The regulation* finally some report* in tt some individuals even different fro*. L' f' "non-deteot h r*, contrary to "*'i f *v ements of ahti.ally ' "T 1 , oblems. OCC 1332 -11- While the new standards did result in the closing of a handful of plants, the industry's all-out effort to meet the OSHA requirements resulted in technological progress that PVC producers themselves did not feel was possible at the time of the hearings. The industrywide cost of compliance has run be tween $300 and $400 million in capital expenditures, with many additional millions being expended yearly in operating expenses. The achievements in reducing exposure have to date far surpassed the expectations of industry executives andtech$>icfl experts alike. ' -' ' - . *..r ,;r "V- "... ; !>.< frr Are the, &&&$& rc io rf; -v- > identifie TdV SoTM studies expofu^.^- - m gpj '; , ."'`sS. ... .... >- $ **$:! V'!. ..f ;rA rical tlA/ 'V ' isfc. Arfi.l1 , V: ',,v-/ of ' tn. intei the e3^osurr,r * I#*.- ^ ' ""i'.! >v/ * .-w `T' v.^f.-r A* ' - & OCC 1333 -12- have estimated the long-term exposure levels of the 23 confirmed U.S. angiosarcoma cases at between 350 and 1,600 ppm. The median length of exposure for these cases was 18 years. The single largest study conducted to date was that under taken by Tabershaw-Cooper Associates and subsequently expanded upon by Equitable Environmental Health, Inc. This study examined the mortality experience of 10,173 workers with at least one year of occupational vinyl chloride exposure and analyzed the cause of death of 707 workers in the study population. As is common for healthy industrial populations, the result* showed a 2t)-30 percent lower than normal death rate from all causes among the workers, whether high or low, or long- or short-term exposure. Cancer*of the digestive system (primarily and, cancers o'* r " exposure ca - Brain cance ory system, |&the high- Signiflean ^t&brease was not rel Ors. pvc pla SI 7 overall dea mediate the high* ikweiler et al. were of limited value in determining a "safe" level for OCC 1334 -13- vinyl chloride exposure since no attempt was made to assess the exposures of the workers studied. In addition, a study by Organization Resources Counselors of more than 4,100 deaths among PVC fabrication workers dis covered not a single case of angiosarcoma. Workers in PVC fabrication, it should be pointed out, were, even in the past, exposed to far lower levels of vinyl chloride than were their fellow workers in the VCM and PVC resin industries. Accusations by the Environmental Defense Fund that this study demonstrated an excess risk of breast cancer from low-level vinyl chloride exposure were proven false when it was foupdkhPP?1: rerexamination that only two of the 44. cases of breast, caacftm in the study had 4t "definite exposur^ ^ Animal iA^atigvj|produced This has wdj&.noij? or more ago. Bow**r* it appears reasonable to conclude that OCC 1335 -14- employees who work their entire lifetime at a level of 1 ppm will have no greater risk of contracting angiosarcoma than workers who were never exposed to vinyl chloride at all. With regard to the question of whether vinyl chloride is capable of causing cancers other than angiosarcoma, the evidence is far from conclusive. Nonetheless, even if future research shows this supposition to be correct, the reduction in exposure to 1 ppm will undoubtedly have taken care of this problem as well. Non-Carcinogenic Effects In early February 1976 Ralph Nader's Health Research Group released to the press the text of a study scheduled' to be printed in the April 9, 19 6, issue of The- Lancet?* The study, by Dr. Infante et al., was cbndtieted'" at a1eingfSl frVC reeift plant in Pennsylvania^; It purported' & show wives of workers exposed to heavy concentfetionr nifieant increi compared to The Sooi istically signistoarriages ;i Iwf:wg' vcm. - engaged eminent s< Departmefip*' of Publ University "<m biom try, '*r -- to undertake independent relieve of thia- , -.-j, Both'Dr? the analytical" !bthddSfJ usid. c"d^'. ____ cal of leading conclusions" drawn by the authors were brought about through the OCC 133 -15- "selection and use of their control group." Dr. MacMahon called the data "worthless," the analysis "naive" and the test "inadequate and misleading." "In short," he said, "this paper is strewn with evidence of carelessness and incompetence and deserves, in my opinion, no consideration whatsoever in weighing the question of whether there is or is not a genetic risk associated with exposure to VCM." Conclusion Since 1974, when the plastics industry first identified and reported the relationship between vinyl chloride exposure and angiosarcoma of the liver in i^uatfiai worfcara, enormous progress has been made 111 redu; levels, Dr. Irving J. Selikof al Sciences Laboratory at. $*e Mew York City, call^t*^ OCC 1337