Fracking Sites May Attribute to Mental Health Issues During Pregnancy

Hydraulic fracturing, a process to stimulate production from new and existing oil and gas wells informally known as fracking, is associated with antenatal mental health issues such as anxiety and depression, according to a new retrospective cohort study.

Researchers sought to uncover a relationship between unconventional natural gas development (UNGD) and adverse birth outcomes in the study. Further objectives were to evaluate:

• Associations between UNGD and antenatal anxiety and depression
• Associations between antenatal anxiety and depression in preterm birth (<37 weeks’ gestation) and reduced term birth weight
• Associations between stochastic direct and indirect effects of UNGD on preterm birth and term birth weight operating through antenatal anxiety and depression
• Associations between effect modification by family-level socioeconomic status

The study, published in the journal Environmental Research, included a total of 8371 births at Geisinger in Pennsylvania between January 2009 and January 2013 to 7715 mothers without prevalent anxiety or depression at conception. A total of 12.2% of mothers in the study accounted for the cases of antenatal anxiety or depression. Researchers acquired phase-specific UNGD activity data from fracking locations available through public sources and categorized exposure as quartile 4 and nonexposure as quartiles 1 to 3. Women who developed anxiety or depression during pregnancy were then compared with unaffected women to test if proximity to fracking sites generated mental health issues.

While the authors did not find significant evidence that fracking was associated adverse birth outcomes, the authors did find that the prevalence of anxiety or depression in pregnant women who were exposed to the highest quartile of UNGD was 15%, as opposed to the lower 3 quartiles’ 11%. Researchers also found that the risk to develop antenatal depression or anxiety was even higher in mothers receiving medical assistance, which signified low family income, compared with non-receiving mothers.

Lead study author Joan Casey, PhD, an assistant professor in the Department of Environmental Health Sciences at Columbia University, highlighted the role fracking sites can have on communities as they can act as stressors that degrade the quality of the natural environment and neighborhoods through the “production of toxic wastewater and increases in truck traffic,” Casey said in a statement. These factors can lead residents to feel a lack of control of their surrounding environment, which ultimately harms their health.

“Another possibility is that air pollution from the sites could be directly contributing to mental health problems in this vulnerable population,” said Casey.

Compared with women in quartiles 1 to 3, the adjusted hazard ratio (HR) for women who lived in the highest quartile of UNGD activity revealed a significant 4.3 additional cases of antenatal anxiety or depression per 100 women (95% CI, 1.5-7.0). Socioeconomic status revealed a heightened risk difference of antenatal mental health issues as well:

• Among mothers receiving medical assistance, 5.6 additional cases (95% CI, 0.5-10.6)
• Among mothers not receiving medical assistance, 2.9 additional cases (95% CI, -0.7-6.5)

The impact that UNGD activity and socioeconomic factors have on pregnant women in the study showcased a significant mental health issue, according to the authors. As fracking waste is disproportionately being placed in lower income areas, it can intensify the effect on pregnant women who are of low income families and are exposed to quartile 4&shy;—level UNGD. Although the research did not find an overall association between high-quartile exposure and adverse birth outcomes, the authors remain determined to continue their research.

“Future research could examine other potential factors like air quality, noise, light pollution, psychosocial stress, and the perception of activities,” said Casey.

Reference

Casey JA, Goin DE, Rudolph KE, et al. Unconventional natural gas development and adverse birth outcomes in Pennsylvania: The potential mediating role of antenatal anxiety and depression. [published online July 23, 2019]. Environmental Research. doi: 10.1016/j.envres.2019.108598.