Abstracts: ISEE 21st Annual Conference, Dublin, Ireland, August 25–29, 2009: Poster Presentations
Background and Objective:
A growing body of research has reported associations between exposure to ambient air pollution and adverse reproductive outcomes. We previously reported associations in a population-based cohort between small for gestational age (SGA) and pre-term birth with regulatory monitor-based and land use regression model exposure estimates. Here we present findings using estimates from the Community Multi-scale Air Quality (CMAQ) modeling system for additional air pollution metrics in the region of Vancouver, Canada.
We identified 70,249 singleton births born between 1999 and 2002 with complete covariate and residential history data. We estimated risk of mean pregnancy exposures on SGA and preterm birth in logistic regression models. We obtained daily average CMAQ model estimates from May 30, 2004 to May 29, 2005, at a grid resolution of 4 x 4 km2; these were linked by month and day to the residential (6-digit postal code) histories of mothers during pregnancy with the actual birth year being retained as a covariate. CMAQ estimates for 20 particle components and 7 gaseous species were included in analyses.
For SGA, elevated ORs were observed for NO/NO2, CO, NH3 and particulate NH4 (accumulation mode). Other particle species associated with elevated ORs were soil and coarse mass, elemental carbon, accumulation mode nitrate and sulfate and primary (but not secondary) organic mass. Although the number of cases was small (N = 241) we observed consistent associations with pre-term birth <30 weeks for unspecified anthropogenic accumulation mode mass, coarse mass, and ammonia.
Exposure estimates derived from the CMAQ model showed associations with birth outcomes that generally were consistent with previous observations based upon monitoring network data and land use regression models. Associations with preterm births <30 weeks were also consistent with prior findings of an association with PM2.5 mass, but also suggest a non-traffic source for this relationship.