Maternal exposure to metal components of PM2.5 and low birth weight in New Mexico, USA

Keywords: Low birth weight (LBW), Air pollution, Exposure assessment, GIS, Particulate matter (PM), Metal components
Abstract Type: Paper Abstract

Abstract

Infants with low birth weight (LBW) are more likely to have health problems than normal-weight infants. In studies examining the associations between particulate matter (PM) exposures and LBW, there is a tendency to focus on PM2.5 as a whole. However, insufficient information is available regarding the effects of different components of PM2.5 on birth weight. This study identified the associations between maternal exposure to 10 metal components of PM2.5 and LBW in offspring based on data aggregated in small areas (geographic units of roughly equal population size) in New Mexico, USA, from 2012 to 2016. This study used a pruned feed-forward neural network (pruned-FNN) approach to estimate the annual average exposure index to each metal component in each small area. The linear regression model was employed to calculate the association between maternal PM2.5 metal exposures and LBW rate in small areas, adjusting for the female percentage and race/ethnicity compositions in the population, and population marriage status and educational level. An interquartile range increase in maternal exposure to mercury and chromium of PM2.5 increased LBW rate by 0.43% (95% confidence interval (CI): 0.18%-0.68%) and 0.63% (95% CI: 0.15%-1.12%), respectively. These findings suggest that maternal exposure to metal components of air pollutants may increase the risk of LBW in offspring. With no similar studies in New Mexico, this study also posed great importance because of the higher LBW rate in New Mexico than the national average. These findings are suggested to be verified through further epidemiological, biological, and toxicological studies.