PREGNANCY AND PERINATAL OUTCOMES IN RELATION TO DRINKING WATER ARSENIC EXPOSURE IN BA MEN, INNER MONGOLIA, CHINA

Abstract

ISEE-465 Introduction: Close to 40 million people worldwide are exposed to levels of drinking water arsenic (DWA) above the WHO recommended maximum limit of 10μg/L. Many studies have documented an association between DWA and cancer, vascular diseases, and dermatological outcomes, but few have investigated the potential adverse effects of DWA on pregnancy and perinatal outcomes. This study was designed to examine the relation, if any, between DWA exposure and adverse perinatal outcomes including low birthweight, preterm delivery, stillborn deliveries, and neonatal mortality in the Bayingnormen (Ba Men) region of Inner Mongolia, China. Methods: Two public health data sources, the Examination Chart for Pregnant Women and a DWA well database, were linked for three counties in the Ba Men region of Inner Mongolia, China. The reference population included all pregnant women who delivered a singleton infant in those three counties between December 1, 1996 - December 31, 1999. Analyses were limited to pregnant women who lived in a subvillage with measured DWA concentrations (n=5,794). Categories of DWA were developed based on the distribution observed (below limit of detection -20 μg/L (reference), 21-50 μg/L, 51-100 μg/L, >100 μg/L). The relations between DWA and low birthweight (<2.5 kg), preterm delivery (<37 weeks gestation), stillborn delivery, and neonatal mortality (newborn death on or before 28 days post delivery) were examined by logistic regression. Results: Exposure to DWA ranged from below limit of detection up to 1200 μg/L. DWA was not associated with a significant increase in low birthweight, stillborn delivery, or neonatal mortality. A significant increase risk in preterm delivery was observed for drinking water arsenic category of 51-100 μg/L (Odds ratio = 8.34; 95% confidence interval 1.05, 66.12) but the overall rate of preterm delivery was lower than expected (2.1%). Discussion: Results from this study suggest that there may be an increased risk of preterm delivery associated with exposure to DWA >50 μg/L but low numbers of preterm infants impacted precision and made the magnitude of potential risks difficult to estimate. Disclaimer: This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.