Recently, a team of colleagues and I decided to closely examine hydraulic fracturing, or fracking, and the impact it has on air quality and the economy in Pennsylvania, where the practice has taken hold.
What we found is that fracking can be linked to about 20 deaths over a seven-year period.
Fracking, a way to tap underground oil and natural gas reserves, is not the hot-button issue it once was in North Carolina less than a decade ago when the state lifted its horizontal drilling moratorium that had been in place since 1945. The explosive growth of the shale gas industry from the mid-2000s has brought unprecedented economic opportunity in many parts of the United States and enhanced national energy security.
Along with those benefits, fracking has other far-reaching effects on the environment and human health. Those who opposed fracking in our state voiced concerns ranging from the further weakening of infrastructure that is threatened regularly by hurricanes and flooding to water pollution, exacerbated in some places by toxic coal ash.
Even though natural gas is considered a cleaner fuel than coal, the shale gas boom also raised alarms regarding local air quality because of the extensive activities associated with well preparation and gas production.
Most fracking activities involve heavy machinery and truck traffic, which lead to emissions of air pollutants like carbon monoxide, nitrogen oxides, hydrocarbons and particulate matter (PM) because of diesel combustion and dust.
PM pollution has known negative health effects including cardiovascular disease, chronic pulmonary obstructive disease (COPD) and stroke, especially among vulnerable populations like pregnant women, infants and the elderly.
With that in mind, Elaine L. Hill of the University of Rochester Department of Public Health Sciences, Neha Khanna and Ruohao Zhang of Binghamton University Department of Economics, Alan J. Krupnick of Resource for Future, Daniel M. Sullivan of the J.P. Morgan Chase Institute and I undertook a study to measure the changes in PM pollution caused by the tremendous growth of the shale gas industry in Pennsylvania.
We specifically focused on Pennsylvania because it overlays the Marcellus shale formation, the largest natural gas field and producer of shale gas in the United States.
To detect the changes in PM pollution caused by well preparation and gas production activities in Pennsylvania, we took advantage of NASA’s satellite-based measurement of aerosol optical depth (AOD), which measures how light is scattered in a vertical column of air from the ground to the satellite sensors every day and is known to be a reliable way to measure ground PM.
The largest pollution is generated when a well is being drilled and fracked and in the first one to two years that it produces gas. Although pollution decreases as a well matures, it can be detected throughout the productive life of a well. What is more, this pollution can be detected as far as 10 km downwind from a well, though the impact drops with distance.
Accounting for airborne transportation of pollution, this increase in PM pollution we measured is large enough to be associated with approximately 20 deaths in Pennsylvania from 2010 to 2017.
This is also only a small part of the total economic cost which is expected to be larger when all types of pollution linked to shale gas development are considered.
Policy makers should weigh these results among the other important factors when they examine fracking. Then they must determine whether there is enough breathing room between the benefits and the risks.
Huan Li, Ph.D., an assistant economics professor at the N.C. A&T Willie A. Deese College of Business and Economics, co-authored “Spatial Spillovers in Airborne Pollution: Air Quality Impacts of Shale Gas Development in Pennsylvania,” presented at the Association of Environmental and Resource Economists virtual conference in June.