Impact of proximity to gas production activity on birth outcomes across the US

Despite mounting evidence on the health effects of natural gas development (NGD), including hydraulic fracturing (“fracking”), existing research has been constrained to high-producing states, limiting generalizability. We examined the impacts of prenatal exposure to NGD production activity in all gas-producing US states on birth outcomes overall and by race/ethnicity. Mata routines were developed to link 185,376 NGD production facilities in 28 US states and their distance-weighted monthly output with county population centroids via geocoding. These data were then merged with 2005–2018 county-level microdata natality files on 33,849,409 singleton births from 1,984 counties in 28 states, using nine-month county-level averages of NGD production by both conventional and unconventional production methods, based on month/year of birth. Linear regression models were estimated to examine the impact of prenatal exposure to NGD production activity on birth weight and gestational age, while logistic regression models were used for the dichotomous outcomes of low birth weight (LBW), preterm birth, and small for gestational age (SGA). Overall, prenatal exposure to NGD production activity increased adverse birth outcomes. We found that a 10% increase in NGD production in a county decreased mean birth weight by 1.48 grams. A significant interaction by race/ethnicity revealed that a 10% increase in NGD production decreased birth weight for infants born to Black women by 10.19 grams and Asian women by 2.76 grams, with no significant reductions in birth weight for infants born to women from other racial/ethnic groups. Although effect sizes were small, results were highly consistent. NGD production decreases infant birth weight, particularly for those born to minoritized mothers.