Scientists Solve the Mystery of Bangladesh's Arsenic-Tainted Water

It was a twisted cycle: In the 1970s, Bangladeshis used surface ponds or rivers to collect rainwater for drinking. But thanks to garbage dumping and sewage, that water became a breeding ground for disease. So UNICEF sought to fix the problem—the agency helped residents drill simple wells that drew water from a shallow aquifer. But this remedy became a tragedy. Bangladesh's groundwater was laced with arsenic. Now, in a study in Nature Geoscience, a team from MIT has answered one of the outstanding pieces of the Bangladesh puzzle: Just how all that arsenic got into the water in the first place.