Air pollution exposure assessment for preschool children: Addressing spatial and temporal variations and social inequities.

Effective air pollution management requires accurate and equitable assessment of population exposure, particularly for vulnerable groups such as children. Traditional exposure assessments, relying on fixed-site monitors or home address modelling, often overlook daily mobility and social disparities. This study presents a novel, high-resolution method for estimating nitrogen dioxide (NO₂) exposure among preschool children in Gothenburg, Sweden, by integrating air pollution dispersion modelling with publicly available administrative data. The method allows for time-weighted exposure analysis. We evaluated the impact of long-term traffic interventions on NO₂ exposure and assessed exposure disparities across socioeconomic strata. Results show that, despite Gothenburg's relatively low pollution levels, 50 % of children living in the city centre were exposed to NO₂ levels above WHO Air Quality Guidelines, reduced to 9 % following traffic interventions. Citywide, exposure above guidelines dropped from 31 % to 6 %. The greatest exposure reductions occurred at preschools with the highest baseline pollution, and children from medium socioeconomic areas experienced the highest exposure. This approach enables improved air quality planning by identifying which interventions most effectively protect vulnerable populations and supports the integration of equity considerations into air pollution mitigation strategies, aligned with the objectives of the revised European Air Quality Directive.