The association between natural gas well activity and specific congenital anomalies in Oklahoma, 1997–2009

Abstract

Background: Natural gas drilling may pose multiple health risks, including congenital anomalies, through air pollutant emissions and contaminated water. Two recent studies have evaluated the relationship between natural gas activity and congenital anomalies, with both observing a positive relationship. Objectives: We aimed to evaluate whether residence near natural gas wells is associated with critical congenital heart defects (CCHD), neural tube defects (NTD), and oral clefts in Oklahoma, the third highest natural gas producing state in the US. Methods: We conducted a retrospective cohort study among singleton births in Oklahoma (n=476,600) to evaluate natural gas activity and congenital anomalies. We calculated an inverse distance-squared weighted (IDW) score based on the number of actively producing wells within a two-mile radius of the maternal residence during the month of delivery. We used modified Poisson regression with robust error variance to estimate prevalence proportion ratios (PPR) and 95% confidence intervals (CI) for the association between tertiles of natural gas activity (compared to no wells) and CCHD, NTD, and oral clefts adjusted for maternal education. Results: We observed an increased, though imprecise, prevalence of NTDs among children with natural gas activity compared to children with no wells (2nd tertile PPR: 1.34, 95% CI: 0.93, 1.93; 3rd tertile PPR: 1.20, 95% CI: 0.82, 1.75). We observed no association with CCHD or oral clefts overall. Specific CCHDs of common truncus, transposition of the great arteries, pulmonary valve atresia and stenosis, tricuspid valve atresia and stenosis, interrupted aortic arch, and total anomalous pulmonary venous connection were increased among those living in areas with natural gas activity compared to those living in areas without activity, though not statistically significant. Discussion: Our results were similar to previous studies for NTDs and specific CCHDs. Future directions include evaluating the association between specific phases of the drilling process and congenital anomalies to better refine the relevant exposure period.

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

“…Several recent studies have suggested that living near OGD during pregnancy may elevate the risk of adverse birth outcomes, including preterm birth (Casey et al 2016;Whitworth et al 2018), small-for-gestational age (SGA) birth (Stacy et al 2015;Tran et al 2020), low birth weight (Hill 2018;Tran et al 2020), and neural tube defects (Janitz et al 2019;Mckenzie et al 2014). However, the findings have not been consistent across studies: McKenzie et al (2014), Stacy et al (2015), and Tran et al (2020) found no association with preterm birth, and Casey et al (2016) and Whitworth et al (2018) found no association with SGA.…”

“…2020 ), low birth weight ( Hill 2018 ; Tran et al. 2020 ), and neural tube defects ( Janitz et al. 2019 ; Mckenzie et al.…”

Residential Proximity to Oil and Gas Development and Birth Outcomes in California: A Retrospective Cohort Study of 2006–2015 Births

“…Previous studies examining the relationship between unconventional OGD and birth outcomes provide suggestive evidence of adverse effects. Although study designs vary, most have characterized OGD exposure based on the density and distance of HF shale gas wells near the maternal residence in urban and rural Colorado (McKenzie et al 2014, Pennsylvania (Casey et al 2015;Currie et al 2017;Hill 2018;Ma 2016;Stacy et al 2015), Oklahoma (Janitz et al 2019), and urban Texas (Walker Whitworth et al 2018. Among the 10 studies, 8 evaluated our outcomes of interest.…”

A spatial analysis of birth defects in Texas, 1999–2011

“…Model 3 includes environmental indicators and community-level factors in addition to the maternal characteristics. As unconventional natural gas developments (UNGD) have been associated with birth defects in Texas and other states, we included density of UNGD wells within 1 km radius of maternal address as a potential environmental exposure that might be contributing to spatial patterns (Janitz, Dao, Campbell, Stoner, & Peck, 2019;McKenzie et al, 2014;McKenzie, Allshouse, & Daniels, 2019;Rabinowitz et al, 2015;Steinzor, Subra, & Sumi, 2013;Tang, Langlois, & Vieira, 2020;Weinberger, Greiner, Walleigh, & Brown, 2017). We included average daily vehicle miles traveled (DVMT) for trucks by county as a measure of traffic-related air pollution; DVMT data were collected from the Texas Department of Transportation for 2005 through 2011 and data for all the years were averaged for a single county-level measure (Texas Department of Transportation, 2019).…”