Study of Arsenic Exposure Risk in Bangladesh Drinking Water Has Potential Implications Elsewhere

July 06, 2010
Lebanon, NH

Photo: Margaret R. Karagas, PhD

Margaret R. Karagas, PhD

A new study published in The Lancet, focusing on the mortality from arsenic contamination of drinking water in Bangladesh, has potential implications for other regions with low level arsenic exposure in drinking water, including New England. According to Margaret Karagas, PhD, co-director of the Dartmouth-Hitchcock Norris Cotton Cancer Center's Cancer Epidemiology and Chemoprevention Program and professor of epidemiology at Dartmouth Medical School, who published a Comment in The Lancet in conjunction with the study, the new research provides valuable data for establishing health and risk guidelines for low levels of arsenic concentration.

The prospective cohort research, called Health Effects of Arsenic Longitudinal Study (HEALS), found that residents of Bangladesh exposed to well water with arsenic concentrations as low as 10 micrograms per liter, or 10 parts per billion, are at potentially increased risk of death. The researchers believe their data demonstrate that an estimated 21% of deaths from all causes and 24% of deaths linked to chronic diseases (including cancers) in Bangladesh could be attributed to drinking arsenic-contaminated well water at concentrations at or greater than 10 micrograms per liter.

The U.S. Environmental Protection Agency limit for arsenic contamination of drinking water is 10 micrograms per liter; according to the New Hampshire Department of Environmental Services, approximately 13% of the drinking-water wells in New Hampshire exceed the EPA limit for arsenic contamination.

Long-term arsenic exposure has been linked with a higher risk of cancers of the liver, kidney, bladder, and skin, vascular disease and other serious health problems. Drinking water contaminated with arsenic is a significant public health problem in at least 70 countries.

In a Comment published with the HEALS research in The Lancet, Dr. Karagas stated: "The beauty of the HEALS cohort is that it includes concentrations at the lower end of the dose-response curve and concentrations at the high end at which known health effects occur. Such data are rarely available, yet they are important for establishing rational guidelines... An estimated 20% of the world's population lacks access to safe drinking water. In 2010, we are reminded once again of the effect of the earth's drinking water supply on the human lifespan and the challenges of securing this scarce resource." Dr. Karagas is currently involved in several ongoing arsenic-related studies in New England.

Dartmouth-Hitchcock Norris Cotton Cancer Center combines advanced cancer research at Dartmouth Medical School with patient-centered cancer care provided at Dartmouth-Hitchcock Medical Center, at Dartmouth-Hitchcock regional locations in Manchester and Keene, NH, and St. Johnsbury, VT, and at 11 partner hospitals throughout New Hampshire and Vermont. It is one of 40 centers nationwide to earn the National Cancer Institute's "Comprehensive Cancer Center" designation.

Learn more about Norris Cotton Cancer Center research, programs and clinical trials online at

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