Combination of instrumental and biomonitoring approaches elucidate the contributions of multiple and contrasted sources of atmospheric exposure to polycyclic aromatic hydrocarbons

<div> A combined approach was implemented to investigate the origins of elevated PAH concentrations in a complex urban environment where numerous emission sources coexist. This approach integrated one year of atmospheric measurements (PM10 filters and continuous atmospheric monitoring), alongside lichen biomonitoring and soil analyses. Results revealed diffuse multi-source contamination, characterized by high PAH levels in both soils and lichens, with a major contribution from the resuspension of soil particles from contaminated brownfields. Pronounced seasonal variations, particularly in winter, reflected the influence of residential heating, with a minor and local contribution from agricultural stubble-burning. Current industrial and port activities were also identified as significant contributors notably through fine particle. The integration of these complementary spatial and temporal approaches enable the ranking of source as follows: (i) resuspension of contaminated soil particles, (ii) industrial and maritime emissions, (iii) residential heating, and (iv) stubble-burning. Combining biomonitoring with atmospheric monitoring provides a robust methodology for characterizing PAH exposure in complex multi-exposure atmospheric contexts, and for guiding environmental health risk management. </div>