Document aDx105Ya6zNkeBZ0ZqYV0LeRa

Brief Report Update to Vinyl Chloride Mortality Study The mortality experience of 593 Dow Michigan Divi sion employees potentially exposed to vinyl chloride after first exposure to vinyl chloride. Both individuals had only short-term exposure in jobs categorized as less was recently updated through 1982. An earlier study than 200 ppm time-weighted average (TWA). evaluated this group for the time period 1942 through There were six deaths from emphysema or chronic 1973 and found an excess of total malignancies among obstructive pulmonary disease (approximately 5 ex the subgroup considered to have the highest exposure.1 pected). None of these individuals worked in areas where However, during the additional period of follow-up there was a potential for exposure to polyvinyl chloride (1974 to 1982), a deficit of malignant neoplasms was dust. observed for this subgroup. An increased risk of lung cancer was not found (stand During the 9 years of additional follow-up, the total ardized mortality ratio = 89) and the study was capable deaths in the study group increased by 63 (to 155) and of ruling out more than a 60% increase with 96% the person-years by 4,234 (to 17,114). The study's certainty. The lack of an association with lung cancer primary focus was directed at cancers of the liver is consistent with the findings from the majority of other (including angiosarcoma), biliary tract, lung, and brain, studies, especially those with the greatest statistical and to emphysema because of previous reports linking power to detect an excess.6 these conditions to vinyl chloride exposure in some work To examine for a dose-response relationship, subjects forces.2'3 No deaths from angiosarcoma were found and were allocated to one of four intensity-of-expoeure cat there were no statistically significant excesses for any egories (undetermined, leas than 25 ppm TWA, 26 to of the other conditions of interest. 200 ppm TWA, and 200+ ppm TWA) based on their Only those employees identified for the original study highest rated job assignment held for at least 1 month. were included in the recent investigation and their work During the updated follow-up histories and exposures were updated through 1977 to deficit of total < ensure a minimum 5-year induction latency period. Con category (8 observed r &4-MWNMQfe sistent with past practice, separate analyses were con entire follow-up period tide ducted first including and then excluding the subset of exoess which was confined j employees with prior, competing exposures to arsenic at least S years of < insecticides.4 v 2.8 expected*}. As was noted in the original study,1 Cause-specific mortality among the study group was there was no predominant tumor site nor eras there a contrasted both with expected levels based on age- and unique histologic type among this subgroup, weakening era-specific mortality rates for US white men, and also any interpretation of a causal link with vinyl chloride. with the mortality experience of 24,410 other male employees from this company location3 who were not exposed to vinyl chloride or arsenic. The comparison with US men is shown in the Table. Wendy 8. Dakar, MPH Total malignant neoplasms were less than expected la Gregory G. Bond, PhD, MPH the updated follow-up period (1974 to 1988), 12 v 16^ and for the total follow-up period (1942 to 1982), 27 v 31.7. There were no statistically significant excesses for Elsie A. McLaren, BN Fred L. Sabel, MS any of the diseases of interest. Similar results were seen Thomas E. Llppe, MD for the comparison with other employees from this com pany location. One death from liver cancer occurred in the study group (0.6 expected). The pathology and autopsy re ports indicated that it was an intrahepatic bile duct carcinoma. There were two deaths from brain cancer Ralph R. Cook, MD, MPH The Dow Chemical Company Epidemiology Health and Environmental Sciencee 1803 Building (1.2 expected), one of which occurred less than 5 years Midland, MI 48674 648 Update to Vinyl Chloride Mortality Study/Dahar et al )_0l529 TABLE Observed and Expected Deaths for Selected Causes Excluding Employees with Prior Exposure to Arsenic Insecticides Causa of Death (ICD-fl) 1942-1973 Ob* Exp* Period of Follow-up 1974-1982 Ob* Exp Ob* 1942--1982 Exp SMRt All causes 80 84.9 50 67.0 130 AH cancers (140-209) 15 15.4 12 16.3 27 Digestive system cancer (150-159) 6 4,4 3 4.1 9 Liver cancer (155, 156) 0 0.3 1 03 1 Respiratory system cancer (160-163) 4 4.9 6 6.4 10 Brain cancer (191, 192) 1 0.6 1 0.5 2 All circulatory diseases (390-458) 38 41 1 27 34 3 65 All nonmalignant respiratory diseases (460-519) 6 42 3 4,4 9 All accidents (E800-E949) 7 8.4 1 2.5 8 * Expected numbers are based on calendar time and age-specific mortality rates of US white men. T Standardized mortality ratio; observed divided by expected number of deaths x 100. $ Cl. confidence interval of Obs/Exp. Not calculated when expected number of deaths fewer than 5. 151.9 31.7 8.5 0.6 11.3 1.1 75.4 8.6 10.9 86 85 106 - 89 -- 86 104 74 95% Cl* 72-102 56-124 48-201 4-899 42-163 23-682 67-110 48-198 32-144 References 1. Ott MG, Langner RK, Holder Bfi: Vinyl chloride exposure in a controlled industrial environment. Arch Environ Health 1975;3Q:333339. 2. Wong O, Whorton MD, Ragland D, et al: An update of an epidemiologic study of vinyl chloride workers. 1942-1982. Prepared for the Chemical Manufacturer's Association. October 17, 1988. 3. Purchase IFH, Stafford J, Paddle GM: Vinyl chloride: An assessment of the risk of occupational exposure. Food Chem Toxicol 1987;25:187-208. 4. Ott MG, Holder 8B, Gordon HL: Respiratory cancer and oc cupational exposure to arsenicals. Arch Environ Health 1974;29;260855. 5. Bond GG, McLaren EA, Cartmill JB, et al: Cause-specific mortality among male chemical workers. Am J Ind Med 1987:12:363383. 6. Beaumont JJ, Brealow NE: Power considerations in epidemio logic studies of vinyl chloride workers. Am J Epidemiol 1981:114:725734. Journal of Occupational Medicine/Volume 30 No. 8/August 1988 649