Cancer mortality of workers exposed to styrene in the U.S. Reinforced plastics and composite industry.
BACKGROUND
Epidemiologic studies have reported increased risk of lymphohematopoietic cancers, lung cancer, and pancreatic cancer after exposure to styrene, although findings across studies are not consistent.


METHODS
We update a large study of reinforced plastic industry workers with relatively high exposures to styrene, examining cancer risks associated with exposure levels. The study includes 15,826 workers who were exposed between 1948 and 1977 with vital-status follow-up from 1948 to 2008. We examine mortality rates associated with cumulative exposure, duration of exposure, peak exposures, average exposure, and time since first exposure to styrene. Exposure estimates were truncated starting in 1977, the period with the lowest exposures, leaving 27% of the study group with incomplete work histories.


RESULTS
The standardized mortality ratios were 0.84 (95% confidence interval = 0.69-1.02) for all lymphatic and hematopoietic cancers combined, 0.72 (0.50-1.00) for non-Hodgkin lymphoma, and 0.84 (0.60-1.14) for leukemia. There was no trend with either cumulative exposure to styrene or number of peaks. Pancreatic cancer deaths were at expected levels (0.96 [0.73-1.22]). There were more lung cancer deaths than expected (1.34 [1.23-1.46]), although with a marked inverse trend with cumulative exposure.


CONCLUSIONS
We found no coherent evidence that styrene exposure increases risk from cancers of the lymphatic and hematopoietic tissue, pancreas, or lung.
Dow Chemical Company, Midland, MI 48674, USA. jjcollins@dow.com
James J
JJ
Collins
Kenneth M
KM
Bodner
James S
JS
Bus
D002423:Cause of Death; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007938:Leukemia / Q000139:chemically induced* / Q000401:mortality; D008175:Lung Neoplasms / Q000139:chemically induced* / Q000401:mortality; D008223:Lymphoma / Q000139:chemically induced* / Q000401:mortality; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D010190:Pancreatic Neoplasms / Q000139:chemically induced* / Q000401:mortality; D016016:Proportional Hazards Models; D012306:Risk; D020058:Styrene / Q000009:adverse effects*; D014481:United States
D020058:Styrene