University of Southern California, Department of Civil and Environmental Engineering, LA, California, USA.
Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
Environ Int. 2018 Nov;120:321-332. doi: 10.1016/j.envint.2018.08.003. Epub 2018 Aug 12.
In this study, source-specific cancer risk characterization of ambient PM-bound polycyclic aromatic hydrocarbons (PAHs) was performed in central Tehran. The positive matrix factorization (PMF) model was applied for source apportionment of PAHs in the area from May 2012 through May 2013. The PMF runs were carried out using chemically analyzed PAHs mass concentrations. Five factors were identified as the major sources of airborne PAHs in central Tehran, including petrogenic sources and petroleum residue, natural gas and biomass burning, industrial emissions, diesel exhaust emissions, and gasoline exhaust emissions, with approximately similar contributions of around 20% to total PAHs concentration from each factor. Results of the PMF source apportionment (i.e., PAHs factor profiles and contributions) were then used to calculate the source-specific lung cancer risks for outdoor and lifetime exposure, using the benzo[α]pyrene (BaP) equivalent method. Our risk assessment analysis indicated that the lung cancer risk associated with each specific source is within the range of 10-10, posing cancer risks exceeding the United States Environmental Protection Agency's (USEPA) guideline safety values (10). Furthermore, the epidemiological lung cancer risk for lifetime exposure to total ambient PAHs was found to be (2.8 ± 0.78) × 10. Diesel exhaust and industrial emissions were the two sources with major contributions to the overall cancer risk, contributing respectively to 39% and 27% of the total risk associated with exposure to ambient PAHs. Results from this study provide an estimate of the cancer risk caused by exposure to ambient PAHs in highly crowded areas in central Tehran, and can be used as a guide for the adoption of effective air quality policies in order to reduce the human exposure to these harmful organic species.
在这项研究中，对德黑兰市中心环境空气中 PM 结合态多环芳烃（PAHs）的来源特异性致癌风险进行了研究。采用正矩阵因子分解（PMF）模型对 2012 年 5 月至 2013 年 5 月期间该地区的 PAHs 进行了源解析。PMF 运行是使用化学分析的 PAHs 质量浓度进行的。确定了五个因素是德黑兰市中心空气中 PAHs 的主要来源，包括石油源和石油残渣、天然气和生物质燃烧、工业排放、柴油尾气排放和汽油尾气排放，每个因素对总 PAHs 浓度的贡献约为 20%。PMF 源解析（即 PAHs 因子分布和贡献）的结果随后用于使用苯并[a]芘（BaP）等效方法计算户外和终生暴露的特定来源肺癌风险。我们的风险评估分析表明，与每个特定来源相关的肺癌风险在 10-10 范围内，致癌风险超过美国环境保护署（USEPA）的指导安全值（10）。此外，发现终生暴露于总环境 PAHs 引起的流行病学肺癌风险为（2.8±0.78）×10。柴油尾气和工业排放是对总癌症风险有重大贡献的两个来源，分别占与暴露于环境 PAHs 相关的总风险的 39%和 27%。本研究的结果提供了对德黑兰市中心高度拥挤地区暴露于环境 PAHs 引起的癌症风险的估计，可作为采取有效空气质量政策的指南，以减少人类接触这些有害有机物质。
