Cancer mortality trends in a blackfoot disease endemic community of Taiwan following water source replacement.

Blackfoot disease is an endemic peripheral vascular disease found among people in a limited area on the southwest coast of Taiwan, where artesian well water has a high concentration of arsenic and was used since the turn of this century. This is an important public health problem and was noted by the authorities, who began improving the water supply in such communities in 1956. This enabled us to test the relationship between arsenic and malignant tumors using a specific exposed community. Study subjects were divided into four groups according to age (under or over 40 yr) and gender. Two methods were used for the estimation of the age-adjusted mortality rate ratios. First, using the first time interval (1971-1973) as the standard, the mortality rate ratio for all malignant tumors was estimated from this interval through to the last interval (1992-1994) using Poisson regression. Cancers that were found to be related to arsenic in previous reports, such as liver, lung, bladder, kidney, and skin cancers, wer...