Published today in the Journal of the American Medical Association, the study provides the first long-term, individual-level evidence that reducing arsenic exposure may lower mortality, even among people exposed to the toxic contaminant for years.

The landmark analysis, led by researchers at Columbia University and New York University, is important for public health because groundwater contamination from naturally occurring arsenic remains a serious issue worldwide. In the United States, more than 100 million people rely on potentially contaminated groundwater sources, especially private wells, for their drinking water. Arsenic is among the most common chemical pollutants.