Characterization, spatial distribution, and health risk assessment of polycyclic aromatic hydrocarbons and heavy metals bounded PM2.5 in urban air of Tabriz, Iran

Introduction: Air and its invisible components play an influential part in the existence of living beings. The two factors of urbanization and industrialization of cities increase the concentration of various compounds in the air. This study has been designed to examine seasonal characterization, spatial distribution and health risk assessment of sixteen Polycyclic Aromatic Hydrocarbons (PAHs) and eleven heavy metals bounded PM2.5 at 16 sites in urban air of Tabriz, Iran. Materials and methods: Glass-fiber filters, peripheral pumps and PMI holder were used with a total 3 L/min flow rate for 24 h sampling Particulate Matter less than 2.5 μm (PM2.5) every 4 seasons at 16 sites from 20nd February to 20th December. Proper solvents are consumed for extraction purposes of these Materials. Inductively Coupled Plasma-Optical Emission Spectrometry (ICP- OES) and Gas Chromatography–Mass Spectrometry GC/MS devices used for analyzing purposes and the spatial distribution of PAHs and heavy metals bounded PM2.5 investigated by ArcGIS 10.3. Excess Lifetime Cancer Risk (ELCR) values and carcinogenicity risk were also calculated for children and adults in different exposure pathways. Results: The annual mean concentrations of PM2.5 were 41.17 μg/m3, ∑16 PAHs bounded-PM2.5 were much higher in autumn and winter (217.47 and 178.32 ng/m3) compared to summer and spring (162.61 and 131.89 ng/m3). The annual mean concentrations of heavy metals bounded-PM2.5 were 138.69 ng/m3. Dermal carcinogenicity risk of exposure with PAHs and ELCR values of heavy metals indicated high risk for adults and children in some stations. Conclusion: Considering the topographic location of the region, Industrial areas and the frequent presence of temperature inversion, such comprehensive researches are needed for control policies