Associations between prenatal exposure to air pollution, small for gestational age, and term low birthweight in a state-wide birth cohort

摘要

A range of health effects, including adverse pregnancy outcomes, have been associated with exposure to ambient concentrations of particulate matter (PM) and ozone (O_3). The objective of this study was to determine whether maternal exposure to fine particulate matter (PM_(2.5)) and O_3 during pregnancy is associated with the risk of term low birthweight and small for gestational age infants in both single and co-pollutant models. Term low birthweight and small for gestational age were determined using all birth certificates from North Carolina from 2003 to 2005. Ambient air concentrations of PM_(2.5) and O_3 were predicted using a hierarchical Bayesian model of air pollution that combined modeled air pollution estimates from the EPA's Community Multi-Scale Air Quality (CMAQ) model with air monitor data measured by the EPA's Air Quality System. Binomial regression, adjusted for multiple potential confounders, was performed. In adjusted single-pollutant models for the third trimester, O_3 concentration was positively associated with small for gestational age and term low birthweight births [risk ratios for an interquartile range increase in O_3: 1.16 (95% CI 1.11, 1.22) for small for gestational age and 2.03 (95% CI 1.80, 2.30) for term low birthweight]; however, inverse or null associations were observed for PM_(2.5) [risk ratios for an interquartile range increase in PM_(2.5): 0.97 (95% CI 0.95, 0.99) for small for gestational age and 1.01 (95% CI 0.97, 1.06) for term low birthweight). Findings were similar in co-pollutant models and linear models of birthweight. These results suggest that O_3 concentrations in both urban and rural areas may be associated with an increased risk of term low birthweight and small for gestational age births.