Flaring from Unconventional Oil and Gas Development and Birth Outcomes in the Eagle Ford Shale in South Texas

摘要

Background: Prior studies suggest exposure to oil and gas development (OGD) adversely affects birth outcomes, but no studies have examined flaring—the open combustion of natural gas—from OGD. Objectives: We investigated whether residential proximity to flaring from OGD was associated with shorter gestation and reduced fetal growth in the Eagle Ford Shale of south Texas. Methods: We conducted a retrospective cohort study using administrative birth records from 2012 to 2015 ( N = 23,487 ) and satellite observations of flaring activity during pregnancy within 5 km of maternal residence. Multivariate logistic and linear regression models were used to estimate associations between four outcomes (preterm birth, small-for-gestational age, continuous gestational age, and term birthweight) and exposure to a low (1–9) or high ( ≥ 10 ) number of nightly flare events, as compared with no exposure, while controlling for known maternal risk factors. We also examined associations with the number of oil and gas wells within 5 km using data from DrillingInfo (now Enverus). Results: Exposure to a high number of nightly flare events was associated with a 50% higher odds of preterm birth [ odds ratio (OR) = 1.50 (95% CI: 1.23, 1.83)] and shorter gestation [ mean difference = ? 1.9 (95% CI: ? 2.8 , ? 0.9 ) d] compared with no exposure. Effect estimates were slightly reduced after adjustment for the number of wells within 5 km . In stratified models these associations were present only among Hispanic women. Flaring and fetal growth outcomes were not significantly associated. Women exposed to a high number of wells (fourth quartile, ≥ 27 ) vs. no wells within 5 km had a higher odds of preterm birth [ OR = 1.31 (95% CI: 1.14, 1.49)], shorter gestation [ ? 1.3 (95% CI: ? 1.9 , ? 0.8 ) d], and lower average birthweight [ ? 19.4 (95% CI: ? 36.7 , ? 2.0 ) g]. Discussion: Our study suggests exposure to flaring from OGD is associated with an increased risk of preterm birth. Our findings need to be confirmed in other populations.