News Feature | November 20, 2014

Arsenic In Water Linked To Lower Breast Cancer Rates

Sara Jerome

By Sara Jerome,

New research suggests arsenic in drinking water might curb the threat of breast cancer.

A new study by researchers from the University of California, Berkeley, and the Pontifical Catholic University of Chile "has linked the chemical element with a 50 percent drop in breast cancer deaths," the Daily Mail reported.

The study was published this month in the journal EBioMedicine.

"We found biologically plausible major reductions in breast cancer mortality during high exposure to inorganic arsenic in drinking water which could not be attributed to bias or confounding. We recommend clinical trial assessment of inorganic arsenic in the treatment of advanced breast cancer," the study said.

Lead author Allan Smith, a Berkeley professor, explained how shocking the results are.

“What we found was astonishing,” Smith said. “We’ve been studying the long-term effects of arsenic in this population for many years, focusing on increased disease and mortality attributed to the historical exposure to arsenic in this population.”

The study focused on Chile residents who had been exposed to high levels of arsenic by mistake.

"Instead of noting a rise in death rates, researchers found breast cancer deaths were cut in half during the period coinciding with high arsenic exposure," the Daily Mail report said. "The effect was more pronounced among women under the age of 60, with mortality reduced in this group by 70 percent."

Why were Chile residents drinking arsenic-laced water?

"In 1958, the northern Chilean city of Antofagasta switched to a geothermal water source originating in the Andes mountains. Years later, it was discovered that the water sources contained more than 800 micrograms per liter of arsenic - 80 times higher than the levels recommended by the World Health Organizations," the Daily Mail report said.

The U.S. EPA considers inorganic arsenic a human carcinogen. "Ingestion of inorganic arsenic by humans has been linked to a form of skin cancer and also to bladder, liver, and lung cancer," the agency says.