The levels of radon — an odorless, radioactive gas — in Pennsylvania have been rising in Pennsylvania since fracking began there, researchers said Thursday, urging residents to take heed and try to get it out of their homes. Their study hasn't established any direct link between fracking and the heightened radon levels. Radon is the second-leading cause of lung cancer in the U.S., killing more than 20,000 people a year, and occurs naturally in many kinds of rock. Levels are high in Pennsylvania, but the researchers in the study just published in the journal Environmental Health Perspectives also found a trend over time: Depending on where in homes radon was measured, radon levels began rising in either 2004 or 2006, and the radon levels were higher in homes where more unconventional drilling, including fracking, was going on nearby.
