Benzene exposure and risk of non-Hodgkin lymphoma.
Smith MT; Jones RM; Smith AH
Cancer Epidemiol Biomark Prev 2007 Mar; 16(3):385-391
Exposure to benzene, an important industrial chemical and component of gasoline, is a widely recognized cause of leukemia, but its association with non-Hodgkin lymphoma (NHL) is less clear. To clarify this issue, we undertook a systematic review of all case-control and cohort studies that identified probable occupational exposures to benzene and NHL morbidity or mortality. We identified 43 case-control studies of NHL outcomes that recognized persons with probable occupational exposure to benzene. Forty of these 43 (93%) studies show some elevation of NHL risk, with 23 of 43 (53%) studies finding statistically significant associations between NHL risk and probable benzene exposure. We also identified 26 studies of petroleum refinery workers reporting morbidity or mortality for lymphomas and all neoplasms and found that in 23 (88%), the rate of lymphoma morbidity or mortality was higher than that for all neoplasms. A substantial healthy-worker effect was evident in many of the studies and a comprehensive reevaluation of these studies with appropriate adjustments should be undertaken. Numerous studies have also reported associations between benzene exposure and the induction of lymphomas in mice. Further, because benzene is similar to alkylating drugs and radiation in producing leukemia, it is plausible that it might also produce lymphoma as they do and by similar mechanisms. Potential mechanisms include immunotoxicity and the induction of double-strand breaks with subsequent chromosome damage resulting in translocations and deletions. We conclude that, overall, the evidence supports an association between occupational benzene exposure and NHL.
Lymphatic-system-disorders; Lymphatic-cancer; Benzidines; Fuels; Gases; Cancer; Occupational-exposure; Occupational-hazards; Occupational-diseases; Animal-studies; Biomarkers
Martyn T. Smith, Division of Environmental Health Sciences, School of Public Health, 216 Earl Warren Hall, University of California, Berkeley, CA 94720-7360
Cancer Epidemiology, Biomarkers & Prevention
University of California, Berkeley