Exposure to natural gas operations in Pennsylvania’s Marcellus Shale correlates with the risk of asthma attacks among asthma patients, according to a new study in the journal JAMA Internal Medicine.
Lead author Sara Rasmussen of the Johns Hopkins Bloomberg School of Public Health said the result could be attributed to either air pollution or stress.
“Natural gas development releases various air pollutants, including particulate matter, volatile organic compounds, and sulphur dioxide,” InsideClimate News reports. “The equipment also produces loud noises and bright lights, which can increase anxiety and sleeplessness. Years of research show that all these factors can exacerbate asthma.”
In contrast to past studies that relied on self-reported symptoms, Rasmussen and her team used detailed medical records from the Geisinger Health System, a company that delivers health care to more than 400,000 people across the state—many of whom live near shale wells.
“The researchers identified 35,508 patients ages five to 90 with a history of asthma between 2005 and 2012,” InsideClimate explains. Then they isolated the individuals who’d reported asthma episodes to Geisinger, analysed the intensity of nearby shale activity, and compared it to the experience of people who hadn’t reported asthma attacks.”
After ranking the patients’ homes based on the surrounding shale activity, the research team “found that residents who lived in homes ranked among the top 25% for production activity were four times more likely to have a mild asthma attack, and 1.7 times more likely to suffer a severe asthma attack, than those in the bottom 25%.”
The next step in the research will be to determine the precise mechanism that links shale activity to asthma attacks. “For the most part, epidemiologists will never say one study proves cause,” Rasmussen told ICN, so definitive conclusions could still be years away.