Regional and seasonal drivers of metals and PAHs concentrations in road dust and their health implications in the Czech Republic.

While car exhaust emissions in the EU are clearly decreasing, the future of non-exhaust emissions looks more pessimistic. The relative importance of the latter is thus expected to increase in terms of air quality and human health. The aim of the study was to assess regional and seasonal differences in the chemical composition of road dust across the Czech Republic and the health impact of its resuspension, with special respect to polycyclic aromatic hydrocarbons and metals. The road dust samples across all regions and seasons were collected. Based on subsequent laboratory and statistical processing, the spatiotemporal distribution of elements and PAHs was evaluated. Next, the contribution of road dust resuspension to air concentrations was estimated and related health impacts were assessed. A significant regional and seasonal variations in PAHs and metals were discovered. Air quality, leading to atmospheric deposition, was the most important factor contributing to these variations. In contrast, road traffic intensity played only a minor role in influencing the concentrations of metals and PAHs in road dust. Exposure to the PM