Study links radon levels in Pennsylvania homes to fracking

Working with Pennsylvania's Geisinger Health System, the researchers analyzed more than 860,000 indoor radon measurements collected by Pennsylvania's Department of Environment Protection from 1989 to 2013. They checked the gas readings against a variety of factors, including underlying rock layers, community wealth and weather.

The study found that buildings relying on well water had higher indoor radon readings than those on municipal water.  They also discovered that summertime first-floor readings tended to be higher in homes relatively close to fracked gas wells, compared with those farther away.

Though there could be other explanations, Schwartz said, the findings appear to be linked to the more than 7,000 gas wells that have been fracked in the state in the past decade. The process involves pumping large quantities of water, sand and chemicals into the ground, then bringing some of it back up with the gas.

Marcellus shale is known to contain uranium, the researchers note, and the flowback water and drilling wastes can contain elevated levels of radium, which can produce radon. They also suggest radon could get into buildings via the natural gas piped in for heating and cooking.

Pennsylvania recently released its own study, finding that there is little potential for harm, either to drillling crews or the public from radiation exposure from fracking operations.

But Schwartz said the Pennsylvania study was based on sampling for radon around nearly three dozen wells. He contended that the Hopkins study provides a better overview of potential exposure because it reviewed hundreds of thousands of readings across the state.

The study comes as lawmakers in Annapolis appear set to impose a 2 1/2-year moratorium on fracking in western Maryland, which sits atop a deposit of potentially gas-rich Marcellus shale.

Amid debate about the safety of fracking and its impact on people's health and western Maryland's tourism industry, the Senate voted 45 to 2 earlier this week to continue a 3 1/2-year de facto moratorium as the state studied how to mitigate the risks.  The legislation requires state regulations be adopted by Oct. 1, 2016, but no permit could be issued until a year later.

Parts of Maryland also have high radon levels. Thirty percent of homes in Garrett County have registered radon levels at or above the threshold at which the Environmental Protection Agency recommends residents take steps to prevent long-term exposure to the gas. The average reading in the county was 5.6 picocuries, above the 4 picocurie threshold, according to EPA data.

But Schwartz said home radon readings may be a misleading indicator of the risks from fracking, as the drilling and extraction process may bring much more radioactive gas to the surface than is currently detected.