Evaluating how urban green space influences pedestrian exposure to black carbon air pollution

Black carbon (BC), a major component of PM2.5 produced by incomplete combustion, is associated with asthma, cognitive deficits, and elevated blood pressure. This study assessed childhood BC exposure in Brooklyn, NY, an area with historically high asthma rates, to examine whether community open space influences exposure after accounting for traffic volume. BC was measured along five community-selected routes near schools using a microAeth AE51 aethalometer. Sampling occurred during the morning and afternoon periods on two weekdays and one weekend day across four separate weeks. The traffic volume was recorded with the Counter + app, and route/time tracking was conducted with MyTracks. The exposure maps were generated in ArcGIS Pro, and the statistical analyses were performed in GraphPad Prism. BC levels varied significantly by route and time of day and were consistently higher in areas with greater traffic counts. Intersections showed significantly elevated BC concentrations compared with walkways (p <0.001). No significant association was observed between community open space and BC levels. Overall, exposures were highest at high-traffic intersections. These preliminary findings highlight the influence of traffic on localized BC exposure and support further investigation into potential health impacts for children in this community.