Seasonal occurrence and cancer risk assessment of polycyclic aromatic hydrocarbons in street dust from the Novi Sad city, Serbia.

This is the first investigation that identified seasonal occurrence, distribution and sources of 16 polycyclic aromatic hydrocarbons (PAHs) in 60 street dust samples collected within urban zone of Novi Sad, the second largest city in Serbia. The obtained results were further used for comprehensive assessment of carcinogenic risk of Serbian inhabitants exposed to PAHs present in street dust by the incremental lifetime cancer risk method. The total level of 16 PAHs ranged between 35 μg kg and 2422 μg kg in samples taken in summer and between 35 μg kg and 587 μg kg in samples taken in winter. In both seasons, 4-ring PAHs were the most dominant compounds and high molecular weight (HMW) PAHs had similar contribution (55% in summer and 65% in winter). The highest content was determined for fluoranthene (Fly) in both seasons (597 μg kg in winter, 301 μg kg in summer). The PAHs source apportionment was analyzed by principal component analysis (PCA) and diagnostic ratios, and combustion of petroleum seemed to be the main sources of the PAHs in street dust. The cancer risk level for children and adult were comparable for dermal contact and by ingestion, and ranged from 10 to 10 indicating a potential risk. Additionally, the total incremental life time cancer risk (ILCR) was assessed for children and adult population taking into account three possible exposure routs and the median total cancer risk was ˃10, with 7% of the samples having the risk ˃10 that should be considered of high concern with potential health problem. These results are the first of this kind for the whole Serbia and the Western Balkan region and can be considered as the base line for future research.