New research from Columbia University found that long term exposure to one naturally occurring metal found in drinking water across the country may lead to an increased risk of heart disease.

Chronic, low-level lead poisoning is a major risk factor for cardiovascular disease in adults and cognitive deficits in children, even at levels previously thought to be safe, according to a paper by Columbia University Mailman School of Public Health, Simon Fraser University in Canada, and Harvard Medical School, and Boston Children's Hospital.