Health effects of ingesting arsenic-contaminated groundwater

Approximately 4% of private drinking water wells in central Outagamie and Winnebago counties contain naturally occurring arsenic at concentrations exceeding the present Environmental Protection Agency (EPA) standard of 50 parts per billion (ppb). This cross-sectional study assessed health status via a self-administered survey. Questions concerned water consumption and resulting neurological, gastrointestinal, and dermatological symptoms. Participants were recruited through a public information campaign recommending water testing through local health departments; the survey was distributed at the time the water sample was submitted. Participants were unaware of their arsenic water concentration before completing the survey. Surveys from 637 families--64% of all surveys distributed--representing 1,836 individuals were completed. Of those respondents, 452 (25%) consumed between 5 and 50 micrograms of arsenic per day through water consumption; 47 (3%) consumed more than 50 micrograms of arsenic per day. This sample size had 80% power to detect a two-fold difference in the prevalence of the health effects studied. At this power level, no significant associations between arsenic intake, estimated through drinking water consumption and water arsenic concentrations, and the health effects studied were established.