Tehran University of Medical Sciences Journal of Air Pollution and Health 2476-3071 7 2 2022 06 29 173 196 Ehsan Ashouri M.s Ahmad Jafari Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran Mitra Golami Research Center of Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran Majid Kermani Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran Mahdi Farzadkia Research Center of Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran Abbas Shahsavani Department of Environmental Health Engineering, School of Public Health and Safety, Environmental and Occupational Hazards Control Research Center Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2022 03 05 2022 05 22 Introduction: Air and its invisible components play a significant role in the existence of living beings. The two factors of urbanization and industrialization of cities lead to an increase in the concentration of various compounds in the air. This study has been designed and performed 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-fibre filters, peripheral pumps and PMI holder were used with a total 3 L/min flow rate for 24 h sampling PM2.5 every four seasons at 16 sites from 20nd February to 20th December. Proper solvents are consumed for extraction purposes of these Materials. ICP-OES and GC/MS devices used for analyzing purposes and the spatial distribution of PAHs and heavy metals bounded PM2.5 investigated by ArcGIS10.3 software. 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, ∑16PAHs 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 was high, and ELCR values of Heavy metals also indicated a 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 assessments and control policies. https://japh.tums.ac.ir/index.php/japh/article/view/363 https://japh.tums.ac.ir/index.php/japh/article/download/363/311