Is Poland at risk of urban road dust? Comparison studies on mutagenicity of dust

Depopulation concerns many polish cities, with the exception of a few metropolises such as Wrocław (Lower Silesia) and Katowice (Upper Silesia) where investments are growing and therefore more humans are exposed to urban environmental pollution. Accumulation of toxic substances on road surfaces is a major global challenge requiring methods of assessing risk that initiate the proper management strategies. In this study urban road dust (URD) has been collected at seventeen sites in Lower and Upper Silesia regions in Poland renowned for their elevated level of pollution. The aim of the study was: (i) to determine PAH concentration in URD in both regions with the identification of their possible sources based on diagnostic ratio; (ii) to assess possible mutagenic effects of URD with the application of Ames test (Salmonella assay); (iii) to define a possible carcinogenic risk related to URD in both studied regions. We found that the total PAH content of collected URD samples ranged from 142.4 to 1349.4 ng g^-1. The diagnostic ratio of PAHs in URD for all studied sites showed that pyrogenic combustion predominated indicating traffic-related and biomass sources of pollution. The Ames assay, which has never been used in studies of URD in Poland, demonstrated that in both regions, URD samples (from eight sites), were characterised by the highest mutagenicity values. Additionally, Incremental Lifetime Cancer Risk (ILCR) values, based on PAH content only, were between 10 and 6 to 10-4 indicating potential risk of cancer. Reassuming, humans in both agglomerations are exposed to factors or compounds with carcinogenic properties which may have an adverse health effect through the urban road dust mainly due to vehicular traffic, heating systems and industrial activities.