PONCA CITY, Okla. - Tests on two homes show they contain unusually high levels of radon gas, a colorless and odorless gas that can cause lung cancer.
The homes contain radon levels of 43.1 and 48.5 picocuries per liter, well above the level considered safe by the Environmental Protection Agency. The EPA recommends action to fix radon gas problems if levels reach 4 picocuries per liter or higher.
Radon comes from the natural breakdown of uranium in soil, water and rock. It escapes from the ground and can seep into homes, where it becomes trapped by poor air circulation.
Radon gas decays into radioactive particles that can get trapped in people's lungs, causing damage to lung tissue.
Radon is the second leading cause of lung cancer in the United States, behind smoking. It is estimated to cause about 14,000 deaths per year.
The average indoor radon level is about 1.3 picocuries per liter, according to the EPA. About 0.4 picocuries per liter of radon is normally found in the outside air.
Nearly one out of every 15 homes in the United States is estimated by the EPA to have elevated radon levels.
Most of Oklahoma _ except for counties in the northeast and the Panhandle _ is considered to be at low-risk for radon problems, said EPA spokesman Mike Broderick.
Homes near the two that tested high for radon gas had normal levels of the gas, said Larry Lake, of Lake Home Inspections.
The houses with high levels of the gas might have had poor air circulation, or a crack in the clay under the homes could have allowed gas to escape into the structures, officials speculated.
The radon level in one of the homes was decreased to 0.5 picocuries per liter after the owner hired a profession radon mitigator from Kansas.
Homeowners can test their houses for radon gas by mailing $18 to the EPA in exchange for a charcoal canister. The canister sits for two days, then is mailed back to the EPA for testing.