Ambient air PM2.5-bound PAHs in low traffic, high traffic, and industrial areas along Tehran, Iran

Polycyclic aromatic hydrocarbons (PAHs) have aroused considerable concern over their ubiquitous presence and potentially hazardous effects on the environment. This research provides the data on PM2.5-bounded PAHs distribution in the ambient air of areas with different land uses of Tehran, Iran. A total of 64 air samples - 16 samples in the industrial area (IS), 24 samples in high traffic areas (HTS), and 24 samples in low traffic areas (LTS) - were taken and analyzed by gas chromatography-mass spectroscopy (GC-MS). The results of this study showed that the mean concentration of ΣPAHs in the air of IS, HTS, and LTS regions was 13.58 ± 18.58, 22.45 ± 33.32, and 33.90 ± 65.006 ng/m3, respectively. The mean concentration of ΣPAHs in samples taken from the IS region was significantly (p < 0.05) higher than that taken from HTS and LTS regions. The source apportionment of PAHs in the air of Tehran was performed using the Unmix.6 EPA receptor model. The results of this model indicated that 41%, 34%, and 26% of PAHs were due to industrial activities and diesel vehicles, traffic and transportation sources, and burning coal and heating appliances, respectively. The total incremental life time cancer risk (ILCR) caused by exposure to PAHs through airborne-PM2.5 of Tehran city was 1.03 × 10−6, 1.51 × 10−6 and 3.23 × 10−6 for LTS, HTS and IS areas, respectively. Estimated results of ILCR indicate that the carcinogenesis risk values in the study area are at an acceptable level (between 10−6–10−4