基于PMF的土壤多环芳烃致癌风险定量源解析方法研究:以太原市为例

为实现土壤PAHs (多环芳烃)来源致癌风险的定量化，选取太原市城乡土壤为研究对象，分析PAHs污染水平并建立含量成分谱，利用PMF (正定矩阵因子分解)模型识别污染源，采用蒙特卡罗模拟进行健康风险评估，并联合PMF模型和健康风险模型量化PAHs污染源的健康风险，比较不同污染源对土壤PAHs含量和对致癌风险贡献的差异. 结果表明:①太原市土壤PAHs污染严重，城市地区人群暴露于土壤PAHs的致癌风险超过了可接受风险水平(10?6)，农村地区人群超过可接受阈值的概率在10%~50%之间. ②城市土壤中PAHs主要来自燃煤交通混合源(41.5%)、燃煤源(26.0%)、石油源(16.2%)、焦炉排放源(8.2%)和交通排放源(8.1%)，农村土壤PAHs主要来自燃煤源(43.3%)、生物质燃烧源(22.3%)、交通排放源(22.7%)和焦炉排放源(11.7%). ③燃煤交通混合源是城市地区致癌风险的最大来源，贡献率为53.7%；交通排放源和燃煤源是农村地区致癌风险的主要来源，贡献率分别为46.3%和45.6%. ④不同污染源对PAHs含量的贡献与其对致癌风险的贡献存在差异，对于城市地区，燃煤交通混合源、交通排放源对PAHs含量的贡献率分别为41.5%、8.1%，而其对致癌风险的贡献率分别为53.7%、13.0%；对于农村地区，交通排放源对PAHs含量的贡献率为22.7%，但其对致癌风险的贡献率为46.3%. 研究显示，规避交通排放源是降低PAHs致癌风险的关键，建议将基于健康风险的定量源解析技术应用到土壤风险管控中，以期更为有效地降低健康风险，保护人体健康. 

Quantitative Source Analysis Method of Carcinogenic Risk of Polycyclic Aromatic Hydrocarbons in Soil Based on PMF Model: A Case Study of Taiyuan

In order to quantify the carcinogenic risk of soil polycyclic aromatic hydrocarbons (PAHs) sources, the urban and rural soils in Taiyuan were selected as the research object. The PAHs contamination levels was analyzed and the concentration profiles were established. The positive matrix factor (PMF) model was applied to identify pollution sources of PAHs, and the Monte Carlo simulation was used for health risk assessment. Based on this, the PMF model and health risk assessment model were used to quantify the health risk of PAHs pollution sources. Then, the differences in contribution of various sources to concentrations of soil PAHs and carcinogenic risk were compared. The results showed that: (1) The PAHs contamination in Taiyuan soil was serious. The carcinogenic risk of exposure to soil PAHs almost all exceeded the acceptable risk level (10?6) for the urban population, while the probability of exceedance for the rural population ranged from 10% to 50%. (2) The PAHs in urban soils were mainly from coal-fired traffic mixed sources (41.5%), coal combustion (26.0%), petroleum sources (16.2%), coke oven emissions (8.2%), and traffic emissions (8.1%), while PAHs in rural soils were primarily from coal combustion (43.3%), biomass combustion (22.3%), traffic emissions (22.7%) and coke oven (11.7%). (3) Coal-fired traffic mixed sources contributed the most to the carcinogenic risk of PAHs in urban areas, accounting for 53.7%. Traffic emissions and coal combustion were the main contributors to the carcinogenic risk of PAHs in rural areas, accounting for 46.3% and 45.6%, respectively. (4) The contribution of different sources to PAHs concentration and carcinogenic risk differed greatly. For urban soil, the contributions of mixed coal-fired traffic sources and traffic emissions sources accounted for 41.5% and 8.1% to the concentration of PAHs, respectively, while the contributions of these sources to the carcinogenic risk were 53.7% and 13.0%, respectively. For rural soil, traffic sources contributed only 22.7% to the concentration of soil, but they contributed 46.3% of the carcinogenic risk. The research results suggest that avoiding traffic emissions sources is important for reducing the carcinogenic risk of PAHs. It is suggested that quantitative source apportionment technique based on health risk should be applied to soil risk control to reduce the health risk more effectively.