【摘要】 污染物在土壤细颗粒组分(PM₁₀和PM_2.5)中的累积对其呼吸颗粒物途径的健康风险评估存在重要影响。针对铬、砷及多环芳烃污染土壤,分析了3种污染物在土壤细颗粒组分中的累积特征及有机质含量对累积因子的可能影响,并基于不同方法比较了呼吸颗粒物途径的健康风险评估结果的差异。结果表明,（1）不同污染物在土壤细颗粒组分中的累积因子存在明显差异。土壤PM₁₀组分中污染物的累积因子在0.008-216.367之间,土壤PM_2.5组分中污染物的累积因子在0.005-415.533之间。六价铬和总铬在细颗粒组分中的累积程度较低,而砷和多环芳烃在细颗粒组分中累积明显。相对于砷和铬,多环芳烃在细颗粒中的累积因子更高且变化范围大,土壤PM₁₀和PM_2.5组分中4环及5-6环多环芳烃所占比例平均值分别达63.11%和58.98%,远高于粒径小于250μm组分中的39.05%。（2）有机质对污染物在细颗粒组分中的累积影响不同,仅当有机质含量较低时,六价铬累积因子大于1;相同有机质或炭黑条件下,4环及5-6环多环芳烃累积因子约为2-3环的1.14-74.69倍;而砷在土壤中的累积基本不受有机质含量的影响。（3）基于不同方法得到的呼吸颗粒物途径健康风险评估结果差异较大,最高相差7个数量级,建议通过实测表层土壤PM₁₀组分中污染物的浓度,作为我国风险评估模型中的暴露参数更为合理可行。更多还原

【Abstract】 The accumulation of contaminants in the fine particle fractions of the soils(PM₁₀ and PM_2.5) has an important impact on the health risk assessment of the respiratory particulate pathway. Focused on chromium, arsenic and polycyclic aromatic hydrocarbons contaminated soils, the accumulation characteristics of three contaminants in fine particle fractions and the possible effects of organic matter content on accumulation factor was analyzed, and compared the differences in health risk assessment results of respiratory particulate pathways based on different methods. The results revealed that:（1） There were significant differences in the accumulation factor of different contaminants in the fine particle fractions of soils. The accumulation factor of contaminants in the PM₁₀ fraction was 0.008-216.367, the accumulation factor of contaminants in the PM_2.5 fraction was 0.005-415.533. The accumulation of hexavalent chromium and total chromium in the fine particle fraction was low, while arsenic and polycyclic aromatic hydrocarbons accumulated obviously in the fine particle fraction. Compared with arsenic and chromium, polycyclic aromatic hydrocarbons had higher accumulation factor in fine particles and a wide range of variation, the average ratio of 4 rings and 5-6 rings polycyclic aromatic hydrocarbons in PM₁₀ and PM_2.5 fractions was 63.11% and 58.98%, respectively, which was much higher than 39.05% of particle size less than 250 μm;（2） Organic matter had different effects on the accumulation of contaminants in fine particle fractions. The accumulation factor of hexavalent chromium was greater than 1 only when the organic matter content was low; in the case of the same organic matter and carbon black content, the accumulation factor of 4 rings and 5-6 rings polycyclic aromatic hydrocarbon were about 1.14-74.69 times of 2-3 rings; however, arsenic in soil was not affected by organic matter; And（3） the results of health risk assessment of respiratory particulate matter pathway based on different methods were quite different, with a maximum difference of 7 orders of magnitude, it is more reasonable and feasible to measure the concentration of contaminants in the PM₁₀ fraction of the surface soil as the exposure parameter in China’s risk assessment model.更多还原