Profiling aerosol Polycyclic Aromatic Compounds (PACs) in a severely polluted European city: A comprehensive assessment of the residential biomass burning impact on atmospheric toxicity

> 0.7). Source apportionment by Positive Matrix Factorization (PMF) on the speciation dataset indicated BB as the major aerosol source, contributing > 80 % to average Σ-PAC concentrations and their carcinogenic potential during the study period. The PAC carcinogenic risk assessment highlighted the importance of considering the inclusion of not only legacy PAHs but also emerging species with very high estimated toxicity, such as Benzo(c)fluorene and Dibenzo-pyrenes. Observed concentrations were alarming, posing substantial short- and especially long-term risks. Therefore, there is an urgent need to regulate residential BB in Ioannina and similar urban environments in SE Europe.