Socioeconomic Inequalities and Ambient Air Pollution Exposure in School-Aged Children Living in an Affluent Society: An Analysis on Individual and Aggregated Data in Belgium

Abstract

Background: Individuals with lower socioeconomic status are at a higher risk of being exposed to adverse environmental factors. Children are more vulnerable to the harmful effects of air pollutants. Therefore, this study examined socioeconomic inequalities in air pollution exposure among children in Flanders, Belgium.Methods: Data were used from 298 children (age range: 9-12 years), and from their parents who participated in the COGNition and Air pollution in Children study. Socioeconomic status (SES) was measured using highest parental education at the individual level and median income at the neighborhood (aggregated) level. Annual average outdoor concentrations of particulate matter with diameters <2.5µm (PM2.5) and <10.0µm (PM10), nitrogen dioxide (NO2), and black carbon (BC) in µg/m3 were estimated at the residential address. Mixed regression models were applied to examine the associations.Results: Parental education level was not significantly associated with air pollution exposure. However, decreasing parental education level demonstrated a trend of increased exposure to PM2.5 by 0.037 µg/m³, PM10 by 0.192 µg/m³, NO2 by 0.394 µg/m³, and BC by 0.023 µg/m³. Children who lived in areas with a lower median neighborhood income were exposed to significantly higher levels of air pollution; an interquartile range (IQR; €4505.00) decrease in income was associated with an increase in exposure to PM2.5 of 0.198 µg/m³, PM10 of 0.406 µg/m³, NO2 of 0.740 µg/m³, and BC of 0.063 µg/m³. Children of parents with a low/high education level had a higher exposure to PM2.5, PM10, NO2, and BC when living in a low income neighborhood. Exposure to all air pollutants was the lowest for high parental education level and high neighborhood income.Conclusions: Low neighborhood income was significantly associated with higher levels of air pollution, while parental education level was not significantly associated. Both individual and aggregated SES data are important to account for air pollution inequalities.

Keywords: Air Pollution, Children, Education level, Neighborhood income