Joseph D. Ayotte and colleagues at the U.S. Geological Survey and the U.S. Centers for Disease Control and Prevention set out to assess arsenic exposure from private water wells on a national level.
The scientists built a model which incorporates a huge dataset comprising tens of thousands of arsenic measurements from wells across the US. This sophisticated model takes into account the facts that can increase or decrease arsenic concentration such as regional and seasonal rainfall, geology, and aquifer chemistry.
The Environmental Protection Agency (EPA) has set a threshold concentration for arsenic in water wells at 10 micrograms per liter. However, some 2.1 million people living the United States could be drinking water contaminated with arsenic whose concentration crosses this threshold. Hotspots are largely concentrated in New England, the upper Midwest, the Southwest, and southern Texas.
“Additionally, by predicting to all of the conterminous U.S., we identify areas of high and low potential exposure in areas of limited arsenic data. These areas may be viewed as potential areas to investigate further or to compare to more detailed local information,” the authors concluded.
Many of these people are largely unaware of the health risks they’re subjecting themselves by sourcing water from unregulated, unmonitored wells. Homeowners are advised to immediately monitor the various chemical concentration found in their water wells if they haven’t done this already. The authors of the study also recommend government officials and policymakers to step up awareness programs and develop new mitigation strategies.