Study links proximity to fracking sites with adverse birth outcomes

Women who lived within 10 km of an oil or gas well that was hydraulically fractured during 1 year preconception or during pregnancy were at higher risk for adverse birth outcomes, according to a study published in JAMA Pediatrics.

In an interview with Healio, co-author Amy Metcalfe, PhD, assistant professor in the departments of obstetrics and gynecology and community health sciences at the University of Calgary in Alberta, Canada, said the idea for the study came from the researchers’ mutual interest in a litany of areas.

Amy Metcalfe

“We each had individual interests in pregnancy outcomes, child development, legislation, geology, environmental health, economics, geography and ultimately in hydraulic fracturing, and oil and gas production in Alberta,” said Metcalfe, who is also a member of the Alberta Children’s Hospital Research Institute.

“We took the opportunity to work together on an interdisciplinary project because it encompassed so many different pillars of research,” Metcalfe said. “Ultimately, environmental health impacts on reproductive health is an area of interest for many of us. It requires such a large team of diverse skill sets to work together, which was an exciting opportunity for us to collaborate.”

The population-based retrospective cohort study included 26,193 women aged 18 to 50 years who had given birth from 2013 to 2018 and lived in rural areas in the Alberta province. The researchers considered subjects “exposed” if they lived within 10 km of an oil or gas well that underwent hydraulic fracturing during the year before conception through pregnancy. They identified 4,871 of these oil and gas wells through the Alberta Energy Regulator.

“What we found was that, for women that have more than 100 fracking sites within 10 km of their home, they have a substantially increased risk for spontaneous preterm birth and being small for gestational age,” Metcalfe said.

Among the 414 women with this level of exposure, the adjusted RRs for spontaneous preterm and small for gestational age were 1.64 (95% CI, 1.04-2.60) and 1.65 (95% CI, 1.10-2.48), respectively. Living within 10 km of any fracking site was associated with an increase in small for gestational age (aRR = 1.12; 95% CI, 1.03-1.23) and major congenital anomalies (aRR, 1.31; 95% CI, 1.01-1.69).

“Certainly, there's a large body of evidence linking, essentially, primarily air pollution and other forms of pollution to adverse pregnancy outcomes, with a clear association between air pollution and spontaneous preterm birth,” Metcalfe said. “I think we weren't surprised to see the number of fracking sites that were happening in Alberta, and the number of them that were happening relatively close to residential dwellings.”

Although Metcalfe cautioned that the researchers could not establish causation, she said they do believe there is an association between fracking and adverse birth outcomes.

“This is also potentially an area where legislation could help protect human health,” Metcalfe said. “Currently in Alberta, the legislation states that a fracking site needs to be 100 m away from an individual residential dwelling, but there’s no legislation regarding density of fracking operation. Certainly, we saw the biggest risk associated with high density operations.”

Reference:

Cairncross ZF, et al. JAMA Pediatr. 2022;doi:10.1001/jamapediatrics.2022.0306.