ARSENIC IN DRINKING-WATER AND INCIDENCE OF URINARY CANCERS

The associations between arsenic ingestion and cancers of the bladder and kidney have been documented in Taiwan. To evaluate further such as sociations for urinary cancers of various cell types, we conducted an ecologic study encompassing 243 townships using cancer registry data o f patients diagnosed between 1980 and 1987. We used the proportions of wells with various specified arsenic levels in each township as indic ators of exposure and evaluated the effects of urbanization and smokin g by an urbanization index and the number of cigarettes sold per capit a. In both genders, we observed associations of high arsenic levels in drinking water with transitional cell carcinomas of the bladder, kidn ey, and ureter and all urethral cancers combined. We also observed suc h associations in adenocarcinomas of the bladder in males, but not in squamous cell carcinomas of the bladder or renal cell carcinomas or ne phroblastomas of the kidney. There was also a positive association bet ween the urbanization index and transitional cell carcinomas of the ur eter in males. The number of cigarettes sold per capita was not a good predictor for urinary cancers. The results indicate that the carcinog enicity of arsenic may be cell type specific.