Arsenic in drinking water and bladder cancer mortality

This study analyzes the relationship between arsenic exposure through drinking water and bladder cancer mortality. The county-specific white male bladder cancer mortality data (1950–1979) and county-specific groundwater arsenic concentration data were obtained for 133 U.S. counties known to be exclusively dependent on groundwater for their public drinking water supply. No arsenic-related increase in bladder cancer mortality was found over the exposure range of 3 to 60 g/L using stratified analysis and regression analyses (both unweighted and weighted by county population and using both mean and median arsenic concentrations). These results, which provide a direct estimate of arsenic-related cancer risk for U.S. residents, exclude the National Research Council’s 2001 risk estimate that was based on Southwest Taiwan data and required adjusting for differences between the body mass and water consumption rates of U.S. and Taiwanese residents. (J Occup Environ Med. 2004;46:298–306) A rsenic has long been known to be ahuman carcinogen, primarily on thebasis of epidemiologic evidence. Therelationship between arsenic expo-sure and various cancers is most clear with respect to the link between occupational inhalation of arsenic in copper smelters and other metal plants and lung cancer,1 and the as-sociation between ingestion of ar-senic by drinking water and skin cancer.2 More recently, studies from Asia (Taiwan, Japan, and Inner Mon-golia) and Latin America (Chile, Ar-gentina, and Mexico) have indicated that ingestion of arsenic in drinking water could also cause bladder, liver, or lung cancer.3–10 Three parts of the world are of great interest to practitioners of en-vironmental medicine concerned with the health-related effects of ex-posure to arsenic in drinking water: Southwest Taiwan, the regions o