In the current work, the concentration, sources, and inhalation-based risk assessment of PM_2.5-bound PAHs and heavy metals was assessed in ambient air of areas with low and high traffic density in Tehran, Iran. To this end, a total of 64 air samples—28 samples in low and moderate traffic areas (LTA), and 32 samples in high traffic areas (HTA))—were taken from March 2018 to March 2019 during warm and cold seasons and analyzed by gas chromatography equipped with mass spectrometry (GC-MS) and inductively coupled plasma-optical emission spectrometry (ICP-OES) to determination of PAHs and metals, respectively. The findings showed that the mean concentration of PM_2.5, PAHs, and heavy metals were 61.08 ± 8.69 μg/m³, 28.69 ± 20.14, and 15,392.7 ± 20,073.0 ng/m³ in the low traffic areas, and 83.00 ± 9.7 μg/m³, 41.1 ± 29.6, and 19,378.2 ± 20,038.0 ng/m³ in the high traffic areas, respectively. Furthermore, the concentration of pollutants in cold season was significantly higher than those of warm season (p < 0.05). The results of source apportionment using Unmix.6 model indicated that 41.1% of PAHs is emitted through industrial activities and diesel vehicles, which are followed by traffic and transportation sources (34.2%) as well as burning coal and heating devices (26.3%). Additionally, risk assessment showed that the risk values of carcinogenicity and non-carcinogenicity resulting from PM_2.5-bound PAHs and metal had exceeded the recommended safe limit by EPA.

在当前的工作中，对伊朗德黑兰交通密度低和高的地区的环境空气中的PM _2.5结合的PAHs和重金属进行了浓度，来源和基于吸入的风险评估。为此，从2018年3月至2019年3月在温暖和寒冷的季节共采集了64个空气样本-低流量和中等流量区域（LTA）的28个样本，以及高流量区域（HTA）的32个样本）并进行了分析用配备质谱仪（GC-MS）和电感耦合等离子体发射光谱仪（ICP-OES）的气相色谱法分别测定PAHs和金属。研究结果表明，PM的平均浓度_2.5，多环芳烃，和重金属分别为61.08±8.69微克/米³，28.69±20.14，和15,392.7 20,073.0±纳克/立方米³在低流量区域，和83.00±9.7微克/米³，41.1±29.6，和19,378.2 20,038.0±纳克/米³在高流量区域，分别。此外，寒冷季节的污染物浓度明显高于温暖季节的污染物浓度（p <0.05）。使用Unmix.6模型进行源头分配的结果表明，PAHs的41.1％是通过工业活动和柴油车辆排放的，其次是交通和运输源（34.2％）以及燃煤和加热装置（26.3％）。此外，风险评估表明，与PM _2.5结合的PAH和金属导致的致癌性和非致癌性风险值已超过EPA推荐的安全限值。