Radium contamination has been found in well water used by hundreds of homeowners who live just north of Annapolis along the Severn and Magothy rivers.
Of the 1,300 wells tested by Anne Arundel County workers, 63 percent had elevated levels of the cancer-causing substance, according to a Washington Post review of county records. A substantial number of wells showed radium levels considered alarmingly high by experts.
Radium dissolves in water and is more than a million times more radioactive than uranium. It was discovered in the county’s water four years ago, when scientists found it while searching for the cause of the county’s high cancer rates.
Traces of radium also have been found in private wells in Prince George’s, Harford and Baltimore counties.
But The Post reports that some wells in Crownsville, Pasadena and Millersville yielded radium levels approaching 593 picocuries per liter. The U.S. Environmental Protection Agency considers 15 picocuries per liter the maximum safe level. Prolonged exposure to radium can cause bone cancer, but 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 disease.
Home water filtration systems that use the ion exchange or reverse osmosis methods can reduce contamination.