A study by researchers at Columbia University Mailman School of Public Health reports that schoolchildren from three school districts in Maine exposed to arsenic in drinking water experienced declines in child intelligence. While earlier studies conducted by the researchers in South Asia, and Bangladesh in particular, showed that exposure to arsenic in drinking water is negatively associated with child intelligence, this is the first study to examine intelligence against individual water arsenic exposures in the U.S. Findings are reported online in Environmental Health.