The latest attempt by researchers to portray natural gas development as harmful to public health fails in its efforts to show hospitalization rates increased with shale drilling in Pennsylvania, pushing instead an unexplained and loosely based connection to cases of urinary and skin diseases in unspecified Marcellus Shale counties.

In a study released last week, researchers from the University of Rochester and Oregon State University examined hospitalization rates from 2003 – 2014 in Pennsylvania counties to find any relationships to the number of wells drilled or the density of wells in those counties. In the end, they found few connections to natural gas and provided even fewer specifics for potential causes or locations of their findings. Here are three key things to keep in mind about this study.

#1 Researchers did not sample for air or water pollution.

As EID has discussed numerous times, a key limitation to the studies that attempt to link oil and natural gas development to health ailments is that researchers fail to actually take any measurements that would show how such impacts could occur. This is something environmental think tank Resources for the Future recently detailed in a five-step “impact pathway” researchers should use to “measure each link in the causal chain that could potentially lead to health impacts from oil and gas development…”

Instead of measuring burdens, concentrations and exposures, researchers simply jumped from activities – individuals living in close proximity to natural gas development – to health impacts – some hospitalizations increased in counties with shale development – without ever measuring for any air and noise pollution (burdens), the intensity of those emissions in relation to the residence (concentrations) or the level of exposure people actually experienced.

To the contrary, there has been extensive research showing that emissions at Pennsylvania’s well sites are not harming nearby residents. This includes the Pa. Department of Health in its 2018 determination that “exposure to the contaminant levels found in ambient air are not expected to harm healthy individuals.” Additionally, there have been four peer-reviewed Appalachian Basin studies since 2017 that concluded fracking is not a threat to groundwater, including one from Penn State University that found water wells in Bradford County had improved in recent years.

The bottom line: existing research has found the pathways to exposure are unlikely to exist and this latest study fails to show otherwise.

#2 No connection to most hospitalizations.

Looking statewide – where hospitalization rates as a whole actually decreased during the study’s timeframe – researchers only found a “positive association” between a county’s well count and cases of genitourinary diseases (such as kidney or urinary tract infections), driven mostly by increased cases among women age 20-64. As for the other 15 major categories of medical diagnoses, the researchers said:

“We found no evidence of association between county-level cumulative well count and hospitalizations for the rest of the broad disease categories or overall hospitalizations in the panel of all Pennsylvania counties.”

The researchers actually found hospitalization rates for infectious and musculoskeletal diseases fell as well-density rose in counties. And only when they removed urban counties from their review did they find a positive association between drilling and skin diseases, mostly among men age 20-64. Perhaps most notably, the data contradicted previous health-related studies claiming similar associations. From the study:

“Previous research found significant associations of UNGD exposure with asthma hospitalizations and pneumonia hospitalizations among the elderly; however, the corresponding outcome in our study includes hospitalizations for all respiratory diseases at a higher level of aggregation, and our estimation did not identify these relationships.” (emphasis added)

#3 Pennsylvania’s highest natural gas producing counties had some of the greatest decreases in overall hospitalizations.

The study does not identify which counties had higher levels of skin and kidney-related hospitalizations, but a map provided in the supplemental materials does give further insight into the overall trend of hospitalizations across the state. Namely, some of Pennsylvania’s highest natural gas producing counties actually had the greatest reduction in hospitalizations during the study period.

For instance, Susquehanna County had the third highest number of shale wells in 2014 (1,103), according to the Pa. Department of Environmental Protection. But as the above map clearly shows, it also fell into the category with the greatest percent change for a decrease in hospitalizations. Washington and Greene counties also saw reductions. Meanwhile, Sullivan County had the highest percentage increase in the state, yet only had 117 wells.

#4 Researchers did not account for other potential causes.

Genitourinary hospitalizations, especially for women, commonly entail kidney, urinary tract infections, or ureter issues. Without data on the health records for each hospitalization, the authors could not account for major risk factors or preexisting conditions for kidney diseases and infections, including genetics, diabetes and high blood pressure.

Similarly, the authors did not take into account whether these issues began prior to shale wells being drilled in the county or whether the patients smoke or used drugs or alcohol.


The researchers could not identify how the presence of natural gas wells would correlate with increases in skin-related hospitalizations, and confessed any further digging into the data was inconclusive:

“Investigation into which specific [skin] diseases may account for these relationships [between fracking and skin-related hospitalization] yielded mixed findings.”

While the researchers claim this is “likely because of the relative rarity of the disease,” as research continues to show it is more likely that it’s because the exposure pathways necessary to have caused such issues are unlikely to exist.

Academic research is important. It is a pillar of the oil and natural gas industry – studies help companies innovate, make decisions, and grow to become more sustainable enterprises. However, the recent wave of research drawing longshot conclusions without examining if a correlation is even realistically possible need to be reviewed with a more critical eye.