More than half of 1,300 wells tested by Anne Arundel County workers in Maryland contained radium in its water, and a significant number of them were at alarmingly high levels, experts said.
Sixty-three percent of homeowners' wells, tested in the area just north of Annapolis along the Severn and Magothy rivers, were contaminated by the cancer-causing substance, according to a Washington Post review of county records.
Radium was discovered in the county’s water four years ago, when scientists were searching for the cause of the county’s high cancer rates. Radium also has been found in private wells in Prince George’s, Harford and Baltimore counties.
The U.S. Environmental Protection Agency considers 15 picocuries of radium per liter the maximum safe level, and The Post reports that some wells in Crownsville, Pasadena and Millersville contained radium levels at almost 600 picocuries per liter. However, officials said contamination in Anne Arundel does not pose a public health threat. They say people would have to drink two liters of radium-contaminated water each day for decades to increase their risk of developing the bone cancer, which is caused by prolonged exposure to radium.
Home water filtration systems using the ion exchange or reverse osmosis methods can reduce radium contamination.