Does the drilling technique boost risk of preterm birth?
Expectant mothers who live near active hydrofracking of natural gas wells are at increased risk for high-risk pregnancies and premature delivery.
The findings shed light on possible adverse health outcomes associated with fracking, or hydraulic fracturing. The drilling technique, which opens up difficult-to-reach gas and oil deposits, has been booming in areas of the United States over the past decade.
Health officials and many residents have been concerned about the effect of the drilling on air and water quality and about stress on residents. Just development of a drill site can require 1,000 truck trips on once-quiet roads. In Pennsylvania in 2006, there were fewer than 100 unconventional gas wells; now there are more than 8,000.
“The growth in the fracking industry has gotten way out ahead of our ability to assess what the environmental and, just as importantly, public health impacts are,” says Brian S. Schwartz, professor of environmental health sciences at Johns Hopkins University Bloomberg School of Public Health.
“More than 8,000 unconventional gas wells have been drilled in Pennsylvania alone, and we’re allowing this while knowing almost nothing about what it can do to health.”
For a new study published in the journal Epidemiology, researchers analyzed data from Geisinger Health System, which covers 40 counties in north and central Pennsylvania. They studied the records of 9,384 mothers who gave birth to 10,946 babies between January 2009 and January 2013 and quantified how close fracking activity was to the mothers’ homes and the stage of drilling, depth of wells, and volume of gas produced during the pregnancies.
Living with the most active quartile of drilling and production activity is associated with a 40 percent increase in the likelihood of a woman delivering pre-term, before 37 weeks of gestation. They also found a 30 percent increase in the chance that an obstetrician had labeled a pregnancy “high-risk,” reflecting factors such as elevated blood pressure or excessive weight gain.
The Centers for Disease Control and Prevention says preterm-related causes of death together accounted for 35 percent of all infant deaths in 2010, more than any other single cause. Being born prematurely is also a leading cause of long-term neurological disabilities in children. Preterm birth cost the U.S. health-care system more than $26 billion in 2005, they say. It should be noted that African-American women have double the rates of preterm birth as their white counterparts.
While the study can’t pinpoint why pregnant women had worse outcomes near the most active wells, every step of the drilling process has an environmental impact. Diesel equipment is used to clear acres of land and transport equipment. Drilling down thousands of feet and then horizontally requires heavy equipment. Fracking then involves injecting millions of liters of water mixed with chemicals and sand to fracture the shale where the gas sits. The fluid is pumped back to the surface. The gas itself also releases pollutants.
“Now that we know this is happening, we’d like to figure out why,” Schwartz says. “Is it air quality? Is it the stress? They’re the two leading candidates in our minds at this point.”
Energy companies moved to fracking when natural gas prices were high and supplies were low. While New York has banned fracking and there is a moratorium in Maryland, Pennsylvania has embraced the industry.
At the peak in 2011, Pennsylvania dug 1,900 wells and gas was $12.11 per thousand cubic feet. And while production is down as prices have plummeted—the state is on track for fewer than 500 new wells in 2015 with the price at $3.69 in July—Schwartz predicts the economy will again shift and fracking will be back in favor.
Policymakers must understand there may be real risks as they make decisions on future wells, Schwartz says. While research is still in its infancy, everything that has come out so far should give decision makers cause for concern.
“The first few studies have all shown health impacts. Policymakers need to consider findings like these in thinking about how they allow this industry to go forward.”