University of Columbia. US: 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 Joseph Graziano, PhD, 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 than 100 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.
Risks of heart
disease and lung, skin and bladder cancers are well documented above the
10-parts-per-billion federal standard. Last year, a Mailman School of
Public Health study led by Dr. Graziano, professor of Environmental Health Sciences,
found that even subtler traces-5 parts per billion-took 5 or 6 points
off the IQs of children who were studied. Maine state officials say that
20 percent of the state’s wells may violate this lower level. “The risk
for pregnant women and children is much higher. We’re hoping that
recognition of the potential consequences for children may be a turning
point in getting more action,” said Graziano, who is also a
pharmacologist. New Jersey, one of the few states to have any
regulations regarding arsenic, has already lowered its limit to 5 parts
per billion.
In conjunction with the Maine Geological Survey and
Maine Center for Disease Control and Prevention, the Columbia team is
now embarking on a project to test ways to motivate well owners in one
county to test their water. Maine legislators are also considering a law
requiring that a well be tested whenever a house is sold.
The
special issue was funded by NIH. Yan Zheng, an adjunct research
scientist at Columbia University’s Lamont-Doherty Earth Observatory
coedited the special section and coauthored some of the articles. U.S.
Geological Survey hydrologist Joseph Ayotte was the special section’s
other coeditor. Other study authors came from Middlebury College, the
Vermont Geological Survey, Castleton State College, University of San
Diego, the University of Ottawa, and the Nova Scotia Department of
Natural Resources.
Read more about the Columbia Superfund Research Program.
Related Research by Dr. Graziano