The Social Context of Environmental Exposures: an Application to Swine CAFO Air Effluent and Pregnancy Outcomes in North Carolina

Abstract

Compared to full weight infants, low birth weight infants are at greater risk for short and long term health consequences. Maternal exposure to air pollution is associated with low birth weight, although these studies did not extend to rural sources of air pollution[1]. The aim of this study was to investigate the association of maternal exposure to swine CAFO air emissions with birth weight. Information on all North Carolina births from 2004-2008 was extracted from the NCDBR. Maternal exposure to swine CAFO air emissions were estimated using NC CAFO water release permitting in a geographic information system. Using ordinary least squares regression modeling, this study implicates a statistically, but not clinically significant association with exposure to swine CAFO emissions and a decrease in birth weight. As the metric of estimated maternal exposure to swine CAFO air emissions became more refined (binary< interaction< exponential decay) the association between swine CAFO exposure and decreased birth weight was increased. Prior studies have found associations between swine CAFOs and poor health in proximate communities, but none have addressed birth weight [2-8]. The results of this research indicate rural sources of air pollution could potentially adversely impact birth outcomes of especially sensitive mothers.