Lancaster County still has some of the highest and most dangerous levels of radon in the state, new Department of Environmental Protection data show.
The findings serve as a reminder to residents here and across the state to test their homes and try to eliminate the gas, which is odorless and is the second leading cause of lung cancer in the U.S.
“It’s just good sense to protect yourself and your loved ones,” Patrick McDonnell, the acting Environmental Protection secretary, said in a written statement about national Radon Action Month.
Pennsylvania’s geology makes the state prone to higher radon levels. The gas has been detected in all 67 counties, and about 40 percent of homes have levels above the Environmental Protection Agency action level, he said.
In Lancaster County, 64 percent or more than 20,000 of all radon tests done between 1986 and 2016 were found to be higher than the recommended EPA standard of 0 to 4 picocuries of radon in every liter of air, according to the state Department of Environmental Protection.
The highest level found in a basement in the county was 650 picocuries per liter and the highest found on a first floor was 188 picocuries per liter, according to the Department.
Simple test kits can be purchased at most home-improvement and hardware stores, or online, for about $20.
There also are 10 radon-mitigation companies based in Lancaster County that sell radon sampling kits. As required by law, they are certified by the Department of Environmental Protection.
Radon occurs naturally from the breakdown of uranium in soil and rocks and enters homes through cracks in the foundation or other openings.
One home in southern Lehigh County showed a radon level of 6,176 picocuries per liter, the highest recorded in the state. That area, like Lancaster County, is near the Reading Prong, a geological section of granite rock that’s historically generated high levels of radon.
Winter is an ideal time to test, because doors and windows are generally closed, producing the most conservative results. High levels of radon tend to be found in basements, but the gas can be found anywhere in the home.
For homes testing high for radon, the U.S. surgeon general and EPA recommend having a professionally installed radon reduction system, using a vent pipe and exhaust fan, to help prevent the radon from entering your home and discharge it outside.