Mortality patterns among workers exposed to styrene in the reinforced plastic boatbuilding industry: An update

Abstract

Background Mortality was updated through 1998 for 5,204 workers exposed to styrene between 1959 and 1978 at two reinforced plastic boatbuilding plants. The a priori hypothesis: leukemia and lymphoma excesses would be found. Methods Standardized mortality ratios (SMR) and 95% confidence intervals (CI) used Washington State and U.S. rates. Results Overall, 860 deaths occurred (SMR 1.09, CI 1.02–1.17), with excess mortality for esophageal cancer (n = 12, SMR 2.30, CI 1.19–4.02), prostate cancer (n = 24, SMR 1.71, CI 1.09–2.54), and accidents (n = 99, SMR 1.26, CI 1.02–1.53). Among 2,062 highly exposed workers, urinary tract cancer (n = 6, SMR 3.44, CI 1.26–7.50) and respiratory disease (n = 12, SMR 2.54, CI 1.31–4.44) rates were elevated. Urinary tract cancer SMR increased with duration of employment. Conclusions We found no excess leukemia or lymphoma mortality. Unanticipated excess urinary tract cancer and respiratory disease mortality, possibly associated with styrene exposure, are difficult to interpret and could be chance findings. Am. J. Ind. Med. 45:165–176, 2004. Published 2004 Wiley-Liss, Inc.