Naturally occurring arsenic in private wells threatens people in many U.S. states and parts of Canada, according to a package of a dozen scientific papers just published by Columbia University and a consortium of many other universities. The Superfund Research Program, directed by Mailman School of Public Health professor Dr. Joseph Graziano, which is focused mainly on New England but applicable elsewhere, says private wells present continuing risks due to almost nonexistent regulation in most states, homeowner inaction and inadequate mitigation measures. The reports also shed new light on the geologic mechanisms behind the contamination. The studies come amid new evidence that even low doses of arsenic may reduce IQ in children, in addition to well-documented risks of cancer, heart disease, and reduced lung function. The reports comprise a special section in the journal Science of the Total Environment.
According to the authors, arsenic is the biggest public-health problem for water in the United States— the most toxic thing we drink – yet for some reason, we pay far less attention to it than we do to lesser problems. Much long-term work on arsenic in the United States and Southeast Asia has been done via an extensive program at Columbia’s Mailman School of Public Health and Lamont-Doherty, part of the Earth Institute at Columbia.
Since the 1990s, the problem has been identified in some 70 countries; it is worst in southeast Asia, where more than100 million people are exposed. Largely unregulated private wells serve some 43 million Americans, where according to a U.S. Geological Survey 6.8 percent tested nationwide violate federal standards governing arsenic in public water supplies. Hot spots are in many states, with patches breaking out through New England, where 20 percent of wells in eastern New England are above limits, affecting some 80,000 people in Maine alone; the contamination rate in the central part of the state is 45 percent. Others affected are in the Great Lakes area, the Pacific Northwest and California, and across the western states into Texas. In 2001, the U.S Environmental Protection Agency lowered the permissible standard from 50 parts per billion down to 10. Public water supplies serving more than 25 people are supposed to meet that standard, and most do—some, by filtering water if necessary. But many small rural public utilities are still in violation, mainly due to cost.
Read more about the Columbia Superfund Research Program.