New, Major Evidence That Fracking Harms Human Health

Hydraulic fracturing, or fracking, may pose a significant—but very local—harm to human health, a new study finds. Mothers who live within two miles of a fracking well are more likely to give birth to a child with a low birth weight—which has been linked to poorer health throughout a person’s life.

The research, published Wednesday in Science Advances, is one of the largest studies done thus far on fracking’s health effects. The authors took the birth records for every child born in Pennsylvania from 2004 to 2013—more than 1.1 million infants in total—and looked at the mother’s proximity to a fracking site, using the state of Pennsylvania’s public inventory of fracking-well locations.

The study was conducted by Janet Currie, an economist at Princeton University, Michael Greenstone at the University of Chicago, and Katherine Meckel at the University of California at Los Angeles.

Birth weight is a straightforward measurement—it is listed on every baby’s birth certificate—but a low birth weight can affect the path of someone’s life. Children with a low birth weight have been found to have lower test scores, lower lifetime earnings, and higher rates of reliance on welfare programs throughout their lives. In one study, researchers examined twins in Norway whose birth weight diverged by 10 percent or more. The lighter twin was 1 percent less likely to graduate from high school and earned 1 percent less than their sibling.

In this new fracking study, researchers found that the correlation held true for siblings who were or were not exposed to a fracking well. Babies who gestated near a well had a reliably lower birth weight than their siblings who were not exposed to the well. (This split could happen perhaps because one sibling was born before the well opened.)

The researchers don’t yet know why this link exists, though they suggest that air pollution could be a possible contributor. The process of fracking may release chemicals into the air, for one, but many wells also run multiple diesel engines at once, and they can be a hub of local activity, with trucks regularly commuting to the sites.

The birth weight of children is affected by many other variables, such as socioeconomic status. But those factors mean that the study may undercount the risk that fracking poses to unborn children. Pregnant mothers living within half a mile of a fracking well may benefit financially from its presence, diluting the negative health effects of the well itself.

While environmental activists and some researchers have proposed that fracking chemicals may leak into groundwater, most studies have failed to find lasting and widespread water pollution near wells. The birth-weight study seems to suggest that air, not water, pollution may instead be the threat that fracking sites pose to human health.