Characterization and health risk assessment of particulate-bound polycyclic aromatic hydrocarbons in Tehran, Iran

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants in the urban atmosphere. An investigation of PAHs in the urban atmosphere of Tehran, Iran, was conducted in this study. Car engine air filters (CAFs) were collected in 15 taxi garages between 2016 and 2017 and analyzed for PAHs to assess the concentration level and health risks of polycyclic aromatic hydrocarbons (PAHs). The total concentrations of 16 PAHs (ΣPAHs) ranged from 169 to 174 μg/CAF. The average ΣPAHs concentration in winter was slightly higher than in summer. The most abundant individual PAH was phenanthrene, followed by fluoranthene, pyrene, and naphthalene. Concentrations of benzo[a]pyrene (BaP) varied between 1.80 and 2.27 μg/CAF. Based on estimated air volumes that pass through each CAF, atmospheric PAHs were estimated. ΣPAHs ranged from 8.31 to 8.39 ng/m 3 for the average air volume estimate, less than those reported before using a high volume air sampler. The total carcinogenic risk of 16 PAH compounds was less than the acceptable limit of EPA for human health (1 × 10 −6 ).