A recently released study from scientists at the University of Pennsylvania suggests a link between hydraulic fracturing ("fracking") for gas and oil and cardiac and neurological illnesses. Whether the report triggers a rash of lawsuits is an open question, particularly because the study appears to make no distinction between the actual activity of fracking relative to all the related industrial activity that occurs in modern well drilling.

The peer reviewed study, Unconventional Gas and Oil Drilling is Associated with Increased Hospital Utilization Rates, measured hospitalizations for cardiology and neurology related events within ZIP codes in three Pennsylvania counties (Bradford, Susquehanna, and Wayne) from 2007 to 2011. The authors identified a statistical association between the number and density of wells within a ZIP code and cardiology events. The study also found a statistical association between the density of wells within a ZIP code and hospital visits for neurology-related events. Put more simply, the study found a significant increase in cardiology and neurology cases in ZIP codes where fracking—really oil and gas exploration—is ongoing. This is not the case in Wayne County, where unlike Bradford and Susquehanna counties, oil and gas drilling has been prohibited by order of the Delaware River Basin Commission.

As with other studies suggesting an association between fracking and health effects, it is not clear that any researcher has yet drawn any direct link between fracking and a specific illness.

To begin, as the study authors themselves note, the study took place over a relatively short period (four years), making it difficult to detect long-term trends. More generally, the study does not identify a specific chemical, process, or route of exposure that might be causing the increased hospitalizations. For this reason alone, it could be difficult for putative plaintiffs to point to this study in an effort to link their cardiology or neurology illness with specific fracking activities as opposed to any of the numerous other steps in the modern oil and gas extraction process.

The study authors also note the possibility that cardiology and neurology events are the result not of fracking, but of increased diesel fumes from trucks and heavy machinery, resulting in air pollution and noise. Also, because the study didn’t control for demographic changes, it is possible that the increase in hospitalizations resulted from an influx of workers living in the ZIP codes studied.

In conclusion, while the study will no doubt get significant attention, it is not clear that it easily could be used to aid plaintiffs in meeting their burden of establishing the required link between any specific compound or chemical or process and any specific adverse health impacts.