COMPARING PARTICULATE MATTER AND OZONE EXPOSURE METRICS FOR PERINATAL EPIDEMIOLOGY IN MEXICO CITY, MEXICO

Background and Aims: Emerging evidence suggests a relationship between air pollution and adverse birth outcomes, but many studies consider only temporal variation in exposure. We compare spatial methods for assessing exposure to outdoor air pollutants in Mexico City with citywide averages. Methods: Three metrics of daily exposures to PM10, PM2.5, and ozone were calculated for a simulated population (n=1,000) in Mexico City during 2008: the citywide average (CWA) (same for all women), and metrics unique to each of the 1,000 hypothetical residential locations: nearest monitor (NM) and inverse distance weighting (IDW). Correlations, mean differences, and their variances were calculated for each pollutant across all three methods, using citywide averages as the reference. Results: Ozone was moderately correlated with PM10 (r=0.54) and PM2.5 (0.65) using CWA. Correlations were lower for IDW (r=0.49 for ozone vs. PM2.5; and r=0.42 for ozone vs. PM10) and NM (r= 0.32 for ozone vs. PM10; and r=0.48 for ozone vs. ...