DENVER – A Colorado School of Public Health study released last week fails to show that living near natural gas development causes birth defects, but that’s not stopping the anti-fracking movement from asserting the opposite.
A slew of environmental groups and anti-fracking media have trumpeted the study as evidence that a pregnant woman’s proximity to natural gas wells can increase the chances of her baby being born with birth defects.
“New Study Shows Proximity to Fracking Sites Increases Risk of Birth Defects,” said a Jan. 30 headline in EcoNews, the Ecowatch website. But the study doesn’t go that far, it only “suggests a positive association” and many of the claims it does make are inconclusive and possibly misleading, according to Dr. Larry Wolk, Colorado’s chief medical officer and executive director of the Colorado Department of Public Health and Environment (CDPHE).
“We agree there is public concern about the effects of oil and gas operations on health, including birth outcomes,” Wolk said.
“While this paper was an attempt to address those concerns, we disagree with many of the specific associations with the occurrence of birth defects noted within the study. Therefore, a reader of the study could easily be misled to become overly concerned,” Wolk said.
The report published Jan. 28 in “Environmental Health Perspectives” used data from the CDPHE and Colorado Oil and Gas Conservation Commission to examine more than 124,000 births between 1996 and 2009 in Garfield County.
The researchers say the study “suggests a positive association between greater density and proximity of natural gas wells within a ten-mile radius of maternal residence and greater prevalence” of certain birth defects, but Wolk countered that the findings “showed only association, not causation, and the statistical differences in birth defects were miniscule.”
“As chief medical officer, I would tell pregnant women and mothers who live, or who at the time of their pregnancy lived in proximity to a gas well, not to rely on this study as an explanation of why one of their children might have had a birth defect,” said Wolk.
“Many factors known to contribute to birth defects were ignored in this study,” Wolk said. “It is difficult to draw conclusions from this study, due to its design and limitations … With regard to this particular study, people should not rush to judgment.”
That hasn’t slowed anti-fracking groups from scrambling to cite the study as proof that living near gas wells can harm newborns.
In a Jan. 30 post on its Facebook page, Frack-Free Colorado shows a photo of a premature baby with a caption attesting that infants whose mothers live near “high-density fracking had a 30 percent greater prevalence of congenital heart defects.”
Gary Wockner, Colorado director of Clean Water Action, told Ecowatch, “These findings suggest that fracking causes babies to be deformed — the more we learn about fracking, the worse it gets.”
Critics have dismissed the study as an obvious effort to provide political ammunition to the anti-fracking movement.
Energy-in-Depth, an industry website, reported that the Colorado School of Public Health researchers were responsible for a 2012 study attempting to link hydraulic fracturing to cancer, which “has morphed into one of the anti-fracking campaign’s most frequently used talking points.”
Wolk listed a series of deficiencies with the study, including that it did not distinguish between active and inactive wells, nor did it identify whether the wells were conventional vertical wells or horizontal wells. The study also failed to examine air or water quality.
“For birth outcomes with very few cases, such as neural tube defects, the authors did not consider the effect that other risk factors may have played (examples: smoking, drinking, mother’s folic acid intake during pregnancy, access to prenatal care, etc),” said Wolk.
“For these rare outcomes, such as neural tube defects, they only considered the effect of elevation. The personal behaviors of the mothers are very important risk factors for all birth defects. Without considering the effect of these personal risk factors, as well as the role of genetic factors, it is very difficult to draw conclusions from this study,” said Wolk.
What’s more, the study actually shows that the closer a mother lives to a natural gas well, the less likely she is to deliver a premature or low birth-weight baby, Wolk said.“The study showed decreased risk of pre-term birth with greater exposure,” said Wolk. “This seems counterintuitive, and again, makes the study difficult to interpret.”