Cancer mortality update with an exposure response analysis among styrene-exposed workers in the reinforced plastics boatbuilding industry

BACKGROUND: There is sparse and inconsistent evidence of an association between styrene exposure and cancer. METHODS: This study examines mortality patterns in a previously studied cohort of 5201 workers employed in two Washington boat-building facilities, extending follow-up 5 years. Standardized mortality ratios (SMR) were calculated using state rates as referent. Cox regression calculated rate ratios (RR) per year employed in styrene-exposed exposed jobs. RESULTS: No excess deaths from lymphohematopoietic cancers (LHCs) were observed (SMR: 0.99, 95%CI: 0.74-1.30) when compared to the referent population; however, the relative risk increased with duration of employment in internal analyses. Conversely, lung cancer mortality was significantly elevated (SMR: 1.24, 95%CI: 1.08-1.41), but there was no evidence of a dose-response relationship. CONCLUSION: We found evidence that occupational exposure to styrene was associated with increased LHC risk, while no such association was observed for lung cancer.