Sludge Watch ==> Arsenic in Drinking Water - Inhibits DNA Repair

[maureen.reilly at sympatico.ca]

http://www.wateronline.com/content/news/article.asp?docid=90e36731-f6ec-45bd-8168-c56e58fb6e92


Dartmouth Study Finds That Arsenic Inhibits DNA Repair

5/31/2006

Hanover, NH —

Dartmouth researchers, working with scientists at the University of Arizona 
and at the Department of Natural Resources in Sonora, Mexico, have published 
a study on the impact of arsenic exposure on DNA damage. They have 
determined that arsenic in drinking water is associated with a decrease in 
the body's ability to repair its DNA.

"This work supports the idea that arsenic in drinking water can promote the 
carcinogenic effects of other chemicals," says Angeline Andrew, the lead 
author and a research assistant professor of community and family medicine 
at Dartmouth Medical School. "This is evidence that it's more important than 
ever to keep arsenic out of drinking water."

The study, which was published online on May 10, 2006, in the journal 
Environmental Health Perspectives, examined the drinking water and measured 
the arsenic levels in samples of urine and toenails of people who were 
enrolled in epidemiologic studies in New Hampshire, and in Sonora, Mexico. 
Andrew and her colleagues examined the data in conjunction with tissue 
samples from the study participants to determine the effect of arsenic on 
DNA repair. To further corroborate their findings, the researchers conducted 
laboratory studies to examine the effects of arsenic on DNA repair in 
cultured human cell models.

"The DNA repair machinery normally protects us from DNA-damaging agents, 
such as those found in cigarette smoke," says Andrew. "The concern is that 
exposure to drinking water arsenic may exacerbate the harmful effects of 
smoking or other exposures."

Andrew explains that in regions of the United States where the rock contains 
higher levels of arsenic, the greater the likelihood that drinking water 
sources contain some potential adverse levels of the toxin. While the levels 
of arsenic in municipal water systems are regularly monitored, there is no 
mandated testing of arsenic levels in private wells. This is of particular 
concern since the regions where arsenic levels are high are in rural 
regions, such as New Hampshire, Maine, Michigan and some regions of the 
Southwest and Rockies. Private wells are common in these areas as primary 
sources of drinking water.

Andrew's co-authors on this paper are: Jefferey Burgess, Maria Meza, Eugene 
Demidenko, Mary Waugh, Joshua Hamilton, and Margaret Karagas, all from 
Dartmouth Medical School, the Department of Environmental and Community 
Health at the University of Arizona, or the Department of Natural Resources 
at the Technological Institute of Sonora, Mexico.

The research was supported by funding from the National Institutes of 
Health, the National Institute of Environmental Health Sciences, the 
National Cancer Institute, the Dartmouth and Arizona Superfund Programs, and 
the American Society of Preventive Oncology.

SOURCE: Dartmouth College