Abstract
OBJECTIVE: This study aimed to evaluate if workers exposed to styrene in reinforced plastics and composite facilities between 1948 and 1977 experienced elevated cancer mortality or mortality risk. METHODS: We performed a mortality update of a 15,826-worker cohort followed from 1948 through 2019. We computed standardized mortality ratios (SMRs) comparing observed deaths to expected deaths based on US national- and state-level age-, race-, sex-, and time-specific mortality rates, and evaluated exposure-response trends. RESULTS: Respiratory system cancer (SMR = 1.30; 95% CI = 1.22-1.39) and lung cancer (SMR = 1.31; 95% CI = 1.22-1.40) mortality was elevated in national-level comparisons. Bladder cancer (SMR = 1.44; 95% CI = 1.11-1.83) and diabetes mellitus (SMR = 1.45; 95% CI = 1.27-1.64) mortality was elevated in state-level comparisons. Internal comparisons did not suggest any exposure-response trends. CONCLUSIONS: We identified no consistent evidence that occupational styrene exposure is associated with elevated cancer mortality risk in this cohort.