Epigenetic and Phenotypic Effects of Fracking Exposure in Children from the Fragile Families and Child Wellbeing Study

Abstract

The development of hydraulic fracturing (fracking) for natural gas over the past decade has radically transformed the nature of U.S. energy, playing a large role in U.S. energy independence. However, these accomplishments have led to a large increase in fracking site development with little regulatory oversight or exploration of consequences of this technique on the health of nearby residents. While recent studies have begun to suggest significant health risks correlated with fracking exposure, the fact that fracking has only emerged in the past few years has limited the number of extensive, longitudinal studies undertaken. Data for examining the epigenetic impacts of fracking exposure are only now becoming available. This study analyzes DNA methylation and phenotype data collected just before the fracking surge and again after six years of sustained fracking development, in an effort to help fill the current gap in understanding. I find suggestive evidence of increasing BMI and accelerating methylation age in children exposed to fracking between the ages of nine and fifteen. I further identify CpGs associated with four genes, ZNF644, RAD18, NAT1, and ABCA1, which appear differentially methylated after fracking exposure. Finally, I identify a gene, DPYD, which contains five differentially methylated CpGs, as well as other genes with multiple differentially methylated CpGs that are implicated in weight gain and toxicant efflux. These findings should encourage further research into the epigenetic effects of fracking. This paper also presents a novel measure of fracking exposure and an analytical framework that will be useful in subsequent work that explores potential links between fracking exposure and DNA methylation.