The Association of PM2.5 and Greenness with Term Low Birth Weight

Abstract

OPS 31: Health effects of multiple environmental stressors, Room 412, Floor 4, August 27, 2019, 1:30 PM - 3:00 PM Background/Aim: Pregnancy exposure to air pollution, particularly PM2.5, has been associated with increased risks of adverse pregnancy outcomes such as preterm delivery and low birth weight. Growing attention has been devoted to investigating the health benefit of exposure to natural environments, including greenness, on pregnancy outcomes. However, the roles of air pollution and greenness exposures on pregnancy outcomes are unclear. Here, we investigated whether greenness exposure modified the relationship between PM2.5 and term low birth weight (TLBW) in a large cohort in Taiwan. Methods: This is a hospital-based cohort study. We obtained data from the Chang Gung Research Database and identified 14,543 live infants born after 37 gestational weeks at the Chang Gung Memorial Hospital between 2010 and 2012. Kriging interpolation method and land-use regression models were applied to estimate daily PM2.5 concentration and monthly PM2.5 concentration, respectively. Greenness exposure was estimated based on the global Moderate Resolution Imaging Spectroradiometer Normalized Difference Vegetation Index (NDVI) database. Logistic regressions were used to estimate marginal and joint effects of PM2.5 and greenness exposures on TLBW. Results: The incidence of TLBW was 3.2%. We found that first trimester PM2.5 exposure was significantly associated with TLBW (the OR at the top quartile of PM2.5 compared with the lowest quartile was 1.84, 95%CI=1.17-2.90). Additionally, the top quartile of NDVI was associated with decreased risk of TLBW compared with the lowest quartile (OR=0.87, 95%CI=0.65-1.16), but not statistically significant. We did not find evidence of significant interaction on a multiplicative scale between PM2.5 and NDVI on TLBW (interaction OR=0.98, 95%CI=0.86-1.12). Conclusions: Our study indicated that first trimester PM2.5 exposure was associated with TLBW, but did not find the join effect of PM2.5 and greenness exposures on TLBW. It will be of importance to further investigate the effect of greenness exposure on pregnancy outcomes.