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This week, the American Medical Association (AMA) released a long-awaited study that confirms what pediatricians, pulmonologists, and parents have been worried about for some time: the risk of developing asthma and needing asthma treatments is directly correlated to proximity to unconventional natural gas wells in Pennsylvania’s Marcellus gas patch. Sara G. Miller summarizes the findings of researchers from Johns Hopkins University in a single sentence:

Researchers found that people who lived close to active fracking wells were more likely to develop mild, moderate or severe asthma compared with those who did not live near active sites, according to the study, published… in the journal JAMA Internal Medicine.


Nearly 26 million Americans (about 8.4% of the population) carry a diagnosis of asthma. To date, nearly than 8,000 unconventional natural gas wells have been drilled in Pennsylvania’s Marcellus Shale region, mostly concentrated in 5 northwestern counties (Bradford, Susquehanna, Lycoming, Tioga, Wyoming) and 5 southwestern counties (Washington, Greene, Butler, Fayette, Westmoreland). Washington County leads the list with more than 1,100 wells. Miller explains that exposure to airborne toxics occurs at every phase of this heavy industrial process and persists well beyond the stage of natural gas production:

There are four steps in this type of natural-gas extraction, and each may be linked to an increased risk of asthma for people living nearby, according to the study. The first step is “well pad preparation,” a monthlong process during which an area of land is cleared and equipment is brought in. The second step is drilling, which can also last about a month, according to the researchers. The third step is the “stimulation” of the drilled well — this is the actual fracking — and lasts about a week, according to the study. The technique involves injecting pressurized liquid into the wells to extract the natural gas.

By this point in the process, more than 1,000 truck trips have been made to carry supplies to and from each site, the researchers added. The final step in the process is gas production.


Lorraine Chow drills down to the nuts and bolts of this study, which has a large sample size:

For the study, lead author and PhD candidate Sara G. Rasmussen, MHS and her colleagues analyzed health records from 2005 through 2012 from the Geisinger Health System, a health care provider that covers 40 counties in north and central Pennsylvania. The researchers identified more than 35,000 asthma patients between the ages of five and 90 years, identifying 20,749 mild attacks, 1,870 moderate ones and 4,782 severe attacks. They then mapped where these patients lived relative to nearby well activity.

The data revealed that people who live nearby a large number or bigger active natural gas wells were 1.5 to 4 times more likely to suffer from asthma attacks compared to those who live farther away. The risk also showed up in all four phases of well development: pad preparation, drilling, stimulation—the actual fracturing—and production.


Ryan W. Miller goes deeper:

Fracking can induce asthma attacks in three ways, according to Barbara Gottlieb, Environment and Health program director at Physicians for Social Responsibility. She was not involved in the study, and PSR as an organization has called for a ban on fracking.

The release of volatile organic compounds can interact with other chemical in the fracking sites to form ground-level ozone, an asthma-inducing pollutant. Increased industrial activity near fracking sites, such as transportation, also aggravates asthma symptoms. And natural gas, or methane, leaks that occur at fracking sites add to asthma exacerbation as well by accelerating climate change and increasing temperatures which increases ground-level ozone.

“It’s really like having a heavy industrial facility on your yard or on your farm,” Gottlieb said.


That young barefoot girl swinging on the swing in the picture above is playing in close proximity to an unconventional natural gas well. Consider the air she is breathing as she swings back-and-forth — air in an idyllic rural neighborhood in the shadow of a heavy industry that emits chemicals such as volatile organic compounds (VOCs — the fumes and vapors of fossil fuels) like toluene and xylene (neurotoxicants), and benzene (leukemia in children); particulate matter (“soot” — cardiotoxic, pneumotoxic, and carcinogenic all by itself);  polycyclic aromatic hydrocarbons (consisting of more than 100 individual chemicals, many are known and suspected endocrine-disrupting toxics; radon gas (carcinogenic); and other gases that poison young lungs (carbon monoxide), make it harder for people to breathe (nitrogen dioxide + VOCs + sunlight = ozone, a major component of air pollution), and warm the planet causing the climate to change (carbon dioxide, and methane itself. It has been estimated that at least 8% of the methane that makes it up from the miles-underground shale rock formation leaks inadvertently or is vented on purpose into the atmosphere. As greenhouse gases go, methane is 86 times more potent than carbon dioxide over a 20-year period!).

Exposure to these chemicals occurs where children live, learn, and play. These industrial toxicants, whose ill-effects we’ve known about from decades of extensive occupational research, get into the air children breathe; spill into surface waters children swim in (lakes, rivers, streams) and ground water aquifers where they get their drinking water; and, because what goes up into the atmosphere eventually comes down, land in the soil where their food is grown. Which airborne toxicant will be diluted by that clean country air — diluted so much that it may be invisible but no less harmful — and drawn into her lungs with each excited breath?  When she descends the hill to the creek below her play yard, the water in which she splashes in this pastoral setting won’t be pure. What dirt and chemicals will the barefoot girl pick up and track into her house after running on the grass back up the hill and around the swing set? Now the outdoor pollutants become indoor dangers.

Children are not like adults:

  • Per unit body weight, they breathe more air, drink more water, and eat more food than adults.
  • They spend more time playing outdoors.
  • Their play tends to be closer to where industrial fallout occurs — in grass, dirt, and bodies of water — and, thus, they are often exposed to higher doses of pollutants.
  • Unlike full-size adults, children (including fetuses and infants) undergo continuous anatomic and physiologic growth and development. Normal processes of growth and development such as cell division, tissue differentiation, and organ migration can be disturbed and interrupted, resulting in birth defects, neurocognitive deficits, and various medical problems that are unique to — or more severe in — children. Asthma is just one of these.
  • Children have a longer “shelf-life” than adults. That is, there is more time for a child to present with clinical manifestations resulting from toxic exposures than an adult exposed at the same time. Children have longer to live than their adults and grandparents; it’s only fair that we acknowledge that.


Our children — the best and most important things each of us has ever made and will ever make — are the most vulnerable people among us. Pollution which emanates from heavy industry is bad enough for adults (air pollution is a major contributor to heart disease, lung disease, and cancer) but it’s worse for our kids. This is what the science has been telling us for a long, long time. Why can’t we get that through our thick adult skulls already?


(Photo: SWPA Environmental Health Project)