PENNSYLVANIA–A U.S. Geological Survey study released Thursday show high levels of cancer-causing radon have been found in some Pennsylvania water wells.
Radon is an odorless, invisible gas that occurs naturally in rocks and soil. It’s the result of the radioactive decay of a natural element called radium. Radon exposure is the second-leading cause of lung cancer in the United States, according to the EPA.
According to the Pennsylvania Department of Environmental Protection, the state has one of the most serious radon problems in the country. An estimated 40 percent of Pennsylvania homes have indoor radon levels above Environmental Protection Agency’s action guideline.
The USGS study, which was conducted in cooperation with the Pennsylvania Departments of Health and Environmental Protection, examined 1,041 well samples and found that 14 percent had radon levels at or above the Environmental Protection Agency’s proposed alternative maximum contaminant level of 4,000 picocuries per liter.
The Peters Creek Schist, a geologic unit in southern York, Lancaster, and Chester counties, was found to have the highest potential radon exposure from both groundwater and indoor air, according to the study. This area also had the highest percentage of private well users, which puts this population at greater potential of exposure to radon from groundwater and indoor air, according to the study.
“This research is not intended to predict radon levels for individual wells; its purpose is to promote awareness regarding potential radon exposure in Pennsylvania and to point out data gaps that exist throughout the state,” said USGS scientist Eliza Gross, who led the study. “The study results and associated potential radon exposure maps provide water-resource managers and health officials with useful data as they consider management actions in areas where radon levels in groundwater and indoor air have been notably high and where people rely on private wells as a water source.”
Homeowners are being encouraged to test their air and water.