LATEBREAKER
Environment/Climate Change
National regulatory change in drinking water arsenic standards and adverse birth outcomes in the state of California, 2000-2017 Ilan Cerna-Turoff* Ilan Cerna-Turoff Madison Stoms Robbie M. Parks Joan A. Casey Julie Herbstman Anne E. Nigra
The 2006 US Environmental Protection Agency’s Final Arsenic Rule (FAR) reduced federal public water arsenic regulatory standards from 50 to 10 μg/L. We examined adverse birth outcomes plausibly associate with arsenic in drinking water (preterm, low birthweight, very low birthweight, and small-for-gestational-age births) and estimated the number averted in California from the FAR implementation. We analyzed electronic birth records from January 1, 2000 to December 31, 2017 (N=9,429,344) and assigned ZIP Code water arsenic concentrations to birth parent residential addresses. We applied an interrupted time series design, with November 1, 2006 as the intervention (~nine months after FAR implementation for gestation length). We used seasonal autoregressive integrated moving average (SARIMA) models to evaluate the difference between observed trends and hypothesized linear slope increases. We stratified analyses by child sex and birth parent’s Hispanic ethnicity, race, ability to pay for prenatal care—a proxy for socioeconomic status—and education level. Sensitivity analyses further estimated adverse births among birth parents who resided in ZIP Codes that reduced water arsenic below 5, 2, and 1 μg/L. We estimated California-wide monthly reductions in preterm births (-21.7, 95% CI -10.2, -33.2), low birth weight (-13.0, 95% CI -6.8, -19.3), and small-for-gestational age births (-22.6, 95% CI -12.3, -32.8). Overall, we estimated the largest effects in infants with birth parents who were Hispanic, white, or had low socioeconomic status. Reductions in preterm births were observed for ZIP Codes that reduced water arsenic below 1 and 2 μg/L. The FAR was associated with reductions in adverse birth outcomes in California (~9888 total from 2006-2017). Greater declines in areas that reduced water arsenic below 1 and 2 μg/L suggests more preterm births may be averted with lower regulatory standards. Federal water regulations are a tool in advancing environmental justice.
