Trace arsenic in water may be linked with diabetes

Trace arsenic in water may be linked with diabetes

A new study based on government date suggests a possible link between low-level exposure to arsenic and Type 2 diabetes.

Previous research outside the United States has linked high levels of arsenic in drinking water with diabetes. It's the link at low levels that's new. The findings appeared recently in the Journal of the American Medical Association.

The United States Geological Survey has developed maps that show where and to what extent arsenic occurs in ground water across the country. The current maps are based on samples from 31,350 wells. Widespread high concentrations were found in the West, the Midwest, and the Northeast.

The analysis of the medical tests of 788 adults found a nearly fourfold increase in the risk of diabetes in people with low arsenic concentrations in their urine compared to people with even lower levels.

Arsenic in ground water is largely the result of minerals dissolving from weathered rocks and soils. It is also an industrial pollutant from coal burning and copper smelting. Utilities use filtration systems to get it out of drinking water.

How arsenic could contribute to diabetes is unknown. But prior studies have found impaired insulin secretion in pancreas cells treated with an arsenic compound.

"The good news is, this is preventable," said lead author Dr. Ana Navas-Acien of Johns Hopkins Bloomberg School of Public Health in Baltimore.

New safe drinking water standards may be needed if the findings are duplicated in future studies, Navas-Acien said. She said they've begun a new study of 4,000 people.

The study's limitations make more research necessary. And public water systems were on their way to meeting tougher U.S. arsenic standards as the data were collected.

The United States lowered arsenic standards for public water systems to 10 parts per billion in 2001 because of known cancer risks. Compliance was required by 2006, years after the study data were collected in 2003 and 2004.