The findings add to growing evidence that ties health concerns to the fracking industry and unconventional natural gas drilling.
Health officials had already been concerned about fracking’s effect on air and water quality, and about stress caused by a thousand or more truck trips on once-quiet roads just to develop a well.
The fracking industry has developed more than 9,000 wells in Pennsylvania in just the past decade.
“Ours is the first to look at asthma, but we now have several studies suggesting adverse health outcomes related to the drilling of unconventional natural gas wells,” says study leader Sara G. Rasmussen, a PhD candidate in environmental health sciences at Johns Hopkins University. “Going forward, we need to focus on the exact reasons why these things are happening, because if we know why, we can help make the industry safer.”
Attacks on the map
Researchers analyzed health records from 2005 through 2012 from Geisinger Health System, which covers 40 counties in north and central Pennsylvania and identified more than 35,000 asthma patients between the ages of 5 and 90.
They identified 20,749 mild attacks (requiring a corticosteroid prescription), 1,870 moderate ones (requiring an emergency room visit), and 4,782 severe attacks (requiring hospitalization). They mapped where the patients lived; assigned metrics based on the location, size, number, phase, total depth, and gas production of the wells; and compared them to asthma patients who didn’t have attacks in the same year.
Asthma sufferers who lived closer to a large number or bigger active natural gas wells were significantly more likely—1.5 to four times more likely—to suffer attacks.
While attacks were likely to occur more frequently throughout all four phases of well development, the increased risk was greatest during gas production, which can last many years. The findings held up even when accounting for other factors that exacerbate asthma, including proximity to major roads, family history, smoking, socioeconomics, and more.
‘A more cautious approach’
The new study, published in JAMA Internal Medicine, can’t pinpoint why asthma attacks are more likely closer to more or larger wells, though researchers say that air pollution and increased stress levels from the noise, traffic, and other community impacts could play a role. Stress has previously been implicated in substantially increasing the risk of asthma attacks.
Previous research has linked the fracking industry, for example, to an increase in such adverse reproductive outcomes as preterm births and lower birth weights, and also to a variety of symptoms such as those involving the skin or upper respiratory tract. The researchers say that drilling and production of wells has become safer and cleaner in the past years, something that would not be captured in this study.
“We are concerned with the growing number of studies that have observed health effects associated with this industry,” says senior author Brian S. Schwartz, a professor of environmental health sciences. “We believe it is time to take a more cautious approach to well development with an eye on environmental and public health impacts.”
Well development also has environmental and community impacts. When well pads are created, diesel equipment clears acres of land, transports equipment, and drills the wells. Drilling down thousands of feet and then horizontally many thousands more requires heavy equipment. Hydraulic fracturing—fracking—then involves injecting millions of liters of water mixed with chemicals and sand to fracture shale where the gas sites.
The fluids are then pumped back to the surface. The gas itself also releases pollutants; leaks can be common. Noise, light, vibration, and truck traffic can be observed near wells, contributing to sleep problems and potentially decreasing home values, both of which could contribute to stress.
New York has banned fracking and there is a moratorium in Maryland, but Pennsylvania has embraced the industry. Hydraulic fracturing has expanded rapidly in recent years in states such as Colorado, North Dakota, and Wyoming. West Virginia and Ohio also allow it.
“Going forward, everyone can learn from Pennsylvania’s experience,” Schwartz says. “State regulatory bodies should use the growing number of health studies to understand the possible environmental and public health impacts of this industry and how to minimize them.”
The National Institute of Environmental Health Sciences, the Degenstein Foundation, the Robert Wood Johnson Foundation, and the National Science Foundation funded the work.
Source: Johns Hopkins University