Mortality among workers at a butadiene facility

Abstract
Several studies of styrene‐butadiene rubber (SBR) workers have reported excess cancers at various sites; however, little could be concluded concerning specific etiologic agents because of the multiple exposures encountered by these groups. The current study examined cause‐specific mortality in a cohort of 2,586 male workers employed for at least 6 months between 1943 and 1979 in a butadiene manufacturing plant that supplied butadiene to two SBR plants. Standardized mortality ratios were calculated using national (NSMR) and local (LSMR) comparison populations. The all‐cause NSMR was 80 (p < 0.05) and the all‐cancer NSMR was 84; the corresponding LSMRs were 96 and 76 (p < 0.05). No significant excesses were observed for any cause of death except lymphosarcoma and reticulum cell sarcoma (NSMR = 235). When the cohort was subdivided into routine, nonroutine, and low‐exposure groups, the SMRs were consistently elevated for this cause of death in all three groups. However, direct comparisons between each of the two exposure groups and the low‐exposure group were inconsistent. This suggests butadiene may not be responsible for the excess, but the association deserves close attention in future studies.