Fracking in Pennsylvania linked with increased hospitalizations
By Ernie Hood
NIEHS-funded researchers have reported associations between increased hydraulic fracturing, or fracking, activity and increased hospitalization rates in three Pennsylvania counties. The study was published July 15 in the journal PLOS ONE.
The authors noted that although they did not show that fracking caused the increased hospitalizations, the strength of the associations during the five-year period studied suggests that health care costs should be considered in analyses of economic benefits from hydraulic fracturing.
The study was conducted by scientists from two NIEHS environmental health sciences research centers — the Center of Excellence in Environmental Toxicology (CEET) at the University of Pennsylvania, and the Center for Environmental Health in Northern Manhattan at Columbia University.
Most comprehensive study to date
The researchers examined more than 95,000 hospital inpatient records from 2007 to 2011, in what they called the most comprehensive study of its kind on the health effects of unconventional gas and oil drilling, which includes fracking. They looked at 25 specific medical categories, as well as overall inpatient prevalence rates. Prevalence refers to the total number of cases in a given population at a given time.
The team also tracked the number of wells created during the fracking process and their density, or number of wells per square kilometer, in three counties that lie on the Marcellus Shale formation in northern Pennsylvania. Bradford and Susquehanna counties experienced dramatic increases in fracking during the five-year period. Wayne County, which was used as a control, had a similar population but no active wells. The number and density of wells was then compared with the prevalence rates for patients from the study area.
Cardiology and neurology admissions linked
The scientists found a statistically significant association between cardiology inpatient prevalence rates and both the number of wells and well density. Neurology inpatient prevalence rates showed a significant association with well density.
The researchers said their findings are remarkable, even though the cause for the increase in inpatient prevalence rates remains unknown, and their approach did not address demographic changes, such as population growth. “We are struck by the finding that these differences were observable within a short period of time from 2007-2011,” the authors wrote. They pointed to a combination of possible factors, including exposure to diesel exhaust and fine particulate matter from truck traffic and well operations.
Insights to guide future studies
Claudia Thompson, Ph.D., NIEHS Population Health Branch lead, said the collaborators are providing new information in a sector where it is sorely needed. “This is environmental epidemiology at its best,” she said, “and we are quite proud that our research centers are working diligently and creatively to characterize links between exposures and adverse human health effects.”
The team was led by CEET Deputy Director Reynold Panettieri Jr., M.D. “Our findings provide important clues for designing epidemiological studies to associate specific toxicant exposures with health endpoints,” he said.
Citation: Jemielita T, Gerton GL, Neidell M, Chillrud S, Yan, B, Stute M, Howarth M, Saberi P, Fausti N, Penning TM, Roy J, Propert KJ, Panettieri RA Jr 2015. Unconventional gas and oil drilling is associated with increased hospital utilization rates. PLoS One 10(7):e0131093.(Summary)
(Ernie Hood is a contract writer with the NIEHS Office of Communications and Public Liaison.)