Implications of spatial and seasonal air pollution patterns, socioeconomic disparities, and 15-minute communities for achieving WHO air quality guidelines

Achieving WHO air pollution guidelines is critical to reduce the health burden of air pollution, which disproportionately affects socioeconomically disadvantaged populations and varies by sector, spatial distribution, and seasonal trends. This study explores the implications of sectorial and spatial-seasonal air pollution patterns, socio-economic disparities, and 15-minute communities to achieve (2021) WHO air quality guidelines for PM_2.5 and NO₂. The study analyses spatial-temporal patterns of air pollution in Belgium. Seasonal air pollution exposure is assessed through summer-to-winter ratios, stratified by land cover, urbanisation, and proximity to roads, and linked to socio-economic disparities using LOESS regression. A case study evaluates the mitigation potential of 15-minute communities for traffic-related air pollution, leveraging the Mobiscore tool to explore the relationship between accessibility and car ownership, a proxy for traffic-related emissions. NO₂ and PM_2.5 show marked seasonal and spatial variations, with higher concentration ratios in summer near busy roads and urban centres, especially for NO₂. In general the NO₂ spatial-seasonal pattern is more heterogenous compared to the PM_2.5 pattern. Winter pollution exposure significantly hampers meeting WHO health targets, although summer levels of NO₂ remain high around major traffic routes. The observed disparities in exposure to NO₂ highlight significant socio-economic inequalities, with the most deprived populations disproportionately burdened by traffic-related air pollution. The results from our case-study to mitigate traffic-related air pollution demonstrate that, up to a Mobiscore of 8.0, car ownership remains constant with increasing availability of services and public transport. From a turning point Mobiscore of 8.0, car ownerships starts to drop significantly, indicating that improving Mobiscores to very high scores ( > = 8.0) may lead to reduced car ownership and lower NO₂ and PM_2.5 emissions and exposure. Our study highlights important spatial-seasonal patterns in air pollution and their health implications, emphasizing the need for season-specific and structural traffic interventions to meet WHO guidelines for PM_2.5 and NO₂ exposure. A case study on mitigating traffic-related air pollution identifies a threshold where sufficient public transport and service accessibility lead to a reduction in car ownership. Addressing socio-economic disparities is crucial, as these areas often face greater challenges in meeting WHO air pollution guidelines, particularly for NO₂.