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

BACKGROUND: Individuals with lower socioeconomic status (SES) 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 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 <2.5 μm (PM 2.5) and <10.0 μm (PM 10), nitrogen dioxide (NO 2), and black carbon (BC) in μg/m 3 were estimated at the residential address. Mixed regression models were applied to examine the associations.

RESULTS: Children from parents with a low education level were exposed to significantly higher levels of PM 2.5, PM 10, and BC compared to children from parents with a high education level. However, the associations were not significant when tested using regression models. 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 PM 2.5 of 0.198 μg/m 3, PM 10 of 0.406 μg/m 3, NO 2 of 0.740 μg/m 3, and BC of 0.063 μg/m 3. Children of parents with a low/high education level had a higher exposure to PM 2.5, PM 10, NO 2, and BC when living in a low income neighborhood. Exposure to all air pollutants was the highest for low parental education level and low neighborhood income.

CONCLUSIONS: Low neighborhood income was significantly associated with higher levels of air pollution, while parental education level was not significantly associated. Children from parents with a low education and low income were exposed to the highest levels of air pollution.