A Lehigh County home has returned the highest concentration of radon ever measured inside a Pennsylvania dwelling, according to the state Department of Environmental Protection.

The home, located in the Center Valley area, registered a measurement of 3,715 picocuries per liter of the cancer-causing radioactive gas, the DEP announced.

The U.S. Environmental Protection Agency recommends any structure with a radon concentration of more than 4 picocuries per liter be remediated.

The DEP, which claims state law prohibits the disclosure of the home's exact address, has recommended its occupants vacate until the radon concentration can be decreased.

"Radon can be a serious health risk to people when they are exposed to high levels of it over a long period of time," DEP Acting Secretary Dana Aunkst said in a statement. "While recent results in this area are among the highest ever measured, it's important to know that the risk is easily remediated."

The colorless, odorless gas occurs naturally in rocks and soil and can enter a home through cracks in the foundation and other openings.

It causes about 20,000 lung cancer deaths in the U.S. each year and is the second-leading cause of lung cancer in Pennsylvania, according to the EPA.

"After 30 years of knowing about this cause of lung cancer in indoor air, the fact that we can still be surprised by such dangerously high levels underscores the need for everyone to test for radon, and to fix problems where they occur," Kevin M. Stewart, director of environmental health for the American Lung Association of the Mid-Atlantic, said in a statement.

Elevated radon levels were first observed in Center Valley-area homes in September, prompting the DEP to send letters and test kit coupons to more than 500 residents, the agency said.

Several other homes in the area have registered radon concentrations of more than 1,000 picocuries per liter, according to the DEP.

The department is taking soil and rock samples for further testing, and has contacted the local school district to ensure radon testing has or will occur there.

The DEP is also encouraging area residents to attend an informational meeting from 4 to 8 p.m. Thursday, Dec. 4 at the Upper Saucon Township Municipal Building.

Though elevated radon concentrations may be more common in certain regions, about 40 percent of homes statewide have the potential for levels above the EPA threshold, according to the DEP.

The U.S. Surgeon General and the American Lung Association recommend all homes be tested for radon, which is the only way to know if high concentrations of the gas exist.

Contact Alex Wigglesworth at 215-854-2305 or awigglesworth@philly.com. Follow @phila_lex on Twitter.
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