Birth Outcomes and Maternal Residential Proximity to Natural Gas Development in Rural Colorado by Lisa M. McKenzie, Ruixin Guo, Roxana Z. Witter, David A. Savitz, Lee S. Newman, and John L. Adgate, Received February 27, 2013, Accepted and Advance Publication January 28, 2014, Environmental Health Perspectives; DOI:10.1289/ehp.1306722
Background: Birth defects are a leading cause of neonatal mortality. Natural gas development (NGD) emits several potential teratogens and US production is expanding.
Objectives: We examined associations between maternal residential proximity to NGD and birth outcomes in a retrospective cohort study of 124,842 births between 1996 and 2009 in rural Colorado.
Methods: We calculated inverse distance weighted natural gas well counts within a 10-mile radius of maternal residence to estimate maternal exposure to NGD. Logistic regression, adjusted for maternal and infant covariates, was used to estimate associations with exposure tertiles for congenital heart defects (CHDs), neural tube defects (NTDs), oral clefts, preterm birth, and term low birth weight. The Association with term birth weight was investigated using multiple linear regression.
Results: Prevalence of CHDs increased with exposure tertile, with an odds ratio (OR) of 1.3 for the highest tertile (95% CI: 1.2, 1.5) and NTD prevalence was associated with the highest tertile of exposure (OR = 2.0, 95% CI: 1.0, 3.9, based on 59 cases), compared to no gas wells within a 10-mile radius. Exposure was negatively associated with preterm birth and positively associated with fetal growth, though the magnitude of association was small. No association was found between exposure and oral clefts.
This study suggests a positive association between greater density and proximity of natural gas wells within a 10-mile radius of maternal residence and greater prevalence of [congenital heart defects] and possibly [neural tube defects], but not oral clefts, preterm birth, or reduced fetal growth. … Recent data indicate that exposure to [natural gas development] activities is increasingly common. The Colorado Oil and Gas Conservation Commission estimates that 26% of the more than 47,000 oil and gas wells in Colorado are located within 150 to 1000 feet of a home or other type of building intended for human occupancy (COGCC 2012). [Emphasis added]