Document RpyBK6KO0NkMONOznXk1D1JVz

Reprinted from the Archives of Bnvironm / Health July 1975, Volume 31 Copyright 1975, American Medical Association Vinyl Chloride Exposure in a Controlled Industrial Environment A Long-Term Mortality Experience in 594 Employees Marvin Gerald Ott, MS; Ralph R. Langncr, PhD; Benjamin B. Holder, MD Vinyl chloride has been associated A new clinical entity associated recently with findings of angiosarcoma in animals and man. The present study examines the mortality experience of indi viduals occupationally exposed to vinyl chloride and lesser amounts of vinyiidene chloride and other compounds. Employees were grouped into lour exposure categories according to the highest levels of vinyl chloride exposure experienced for at least one month. with vinyl cMoridc exposure, acroosteolysis, was reported in the United States by Wilson et al in 1967.' This was elaborated by Cook et ai/' Dodson et al," and Dinman et al.r In 1972, an environmental study of vinyl chloride workers by Kramer and Mutchler* revealed laboratory indica tions of liver disease in workers Although no angiosarcomas were found exposed to a time-weighted average and there were no deaths due to any fiver concentration for an eight-hour flay malignancy, the observer* nw_ deaths exceeded the expected among workers in the high-exposure category. Fewer than expected malignancy deaths were observed in the remaining exposure categories. (TWA) of 300 ppir. or above. .. . of other effects associated with expo sure to high levels of vinyl chloride were summarized by Marstellar and Juhe:' in the European literature. Neoplasia was first associated with vinyl chloride in 1971 by Viola et al.'" Maltoni" later reported malignant changes in animals, including angio Vinyl chloride has a 30- to 40-year history of industrial use. Until sarcoma of the liver. Creech and John son11 supported this observation by recently, it was thought to be a relatheir report of angiosarcoma of the tively benign material and, in fact, liver in vinyl chloride workers. In May was once considered for use as a 1974, Tabershaw and Gaffev" re surgical anesthetic. Reports docu leased their industry-wide epidemio menting anesthetic elTects in animals logical study of vinyl chloride workers and humans and liver injury in ani that suggested increased numbers of mals from chronic exposure were malignant neoplasms at other body published in 1960 thru 1963 by Mastro- sites. matteo et at,' Torkelson et al,J and This report summarizes the mortali Lester et ai.1 ty experience of an industrial popula tion exposed to vinyl chloride in an environment for which many years of Submitted For publication Au(! Ai. 1974; ifcrpied Feb iS, 197.V From ihe Dow Chemical Company, Midland. Mich. Reprint requests to the Dow Chemical Compa ny. Corporate Medical Department. COHO Dow Center. Midland, Ml 4M'<40 (Mr. Oil). monitoring data arc available. Many of the employees wore also included in the Tabershaw and Gaffev report; however, in the present study the mortality experience was combined with more clearly defined levels of exposure and follow-up of former company employees. HISTORY Research involving vinyl chloride started at this company location in the mid-1930s. In 1941, a small copolymer plant was constructed that employed four operators, two miller-packagers, one foreman, and one superintendent. In the late 1940s, the plant capacity was enlarged and two assistant opera tors joined the work force. Tb* mer plant continued to grow and other types of copolymer were developed, which resulted in a larger department with a new group of operating, cleri cal. and supervisory personnel. A small production unit to produce vinyl chloride monomer and a copolymer semiplant also were operated during this period. Continued research resulted in a new outdoor homopolymer (PVC) and copolymer unit being constructed in 1952. The rapid development of the market for PVC resin in the 1950s outstripped the new plant capacity. In response, PVC production was begun in a portion of a third copolymer unit that had previously used only limited quantities of vinyl chloride. Thus, besides the research efforts and mon omer production, three polymer units were in operation. The PVC was pro duced until 1969, when the decision was made to discontinue production of homopolymer and use the facilities to modernize copolymer production. The modernization allowed the closing of the plant built in 1941. Arch Environ Health/Voi 30. July 1975 Vinyl Chloride Exposure/Ott et al 333 RSV 0006603