The effects of disinfectant by-products on the risk for urinary bladder and rectal cancers.

摘要

This study addresses two topics: (1) the national spatial and temporal patterns of mortality for urinary bladder and rectal cancers in males in the continental United States for the time period 1968-1998, and (2) the risks for urinary bladder and rectal cancers associated with exposure to the disinfectant by-product group trihalomethanes in public drinking water. Entrenched spatial patterns of mortality which exhibit a bias towards regions in the Northeastern United States are found in the national trends for both diseases over the thirty one year time period. Reasons for these entrenched patterns of mortality are not entirely clear but may be related to high out migration rates, exposure to carcinogens in the environment, spatial variability in health care access, or variability in other covariate risk factors that exhibit a spatial bias associated with either cancer.; A case-control study is conducted which accounts for a host of lifestyle covariates, and represents one of the most comprehensive assessments to date of the effects of trihalomethanes (by-products of the water disinfectant process) on the risk for urinary bladder and rectal cancers in white males. Concurrent with previous studies of the effects of trihalomethanes in disinfected water supplies, the current study demonstrates increasing risk with increasing exposure. Evidence of increased risk applies to groups of cases exposed to levels of trihalomethanes that are well within the legal limit for these compounds.