如何更准确地评估土壤污染健康风险是国内外研究的难点。传统经口摄入土壤途径健康风险评估方法不考虑手尘土壤的粒径分异，但由于不同区域土壤与污染物分布模式存在明显的粒级效应，常常导致过高或过低的风险评估，对风险管理造成不确定性。因此，本研究以“手尘粒径分布及其主要影响因素”为切入点，以我国广东、天津和甘肃地区典型石油化工场地周边3-6岁敏感群体儿童为研究对象，选择多环芳烃为特征污染物，研究不同地域儿童手尘的粒径分布特征和变化规律；结合土壤特性、儿童行为活动模式特征、自然环境等探究其关键影响因素；基于手尘粒径分布分析场地土壤相应粒径下的污染物浓度和生物可给性；最终建立基于手尘粒径分布校正和生物可给性的土壤污染物精细化人体经口暴露健康风险评估新方法和新模型。成果可为精细化健康风险评估提供新思路，对土壤污染风险管控具有重要意义。

How to assess the health risk posed by soil pollution more accurately is a great difficult point. Traditional methods for health risk of oral exposure to soil contaminants don’t take into account the particle size variations of hand dust, but due to the obvious particle size distribution patterns of soil and soil contaminants in different regions, it often lead to too high or too low risk assessment, which leads to uncertainty of risk management. Therefore, the particle size distribution of the hand dust and its key influencing factors will be taken as the breakthrough point of this research. The sensitive group children aged 3-6 years living around the typical petrochemical site located in Guangdong, Tianjin and Gansu provinces of China respectively will be recruited as the research object, and PAHs will be selected as the specific pollutants. This project will study the particle size distribution characteristics and changing rules of children’s hand dust, and explore the key influencing factors by combining the characteristics of soil, natural environment, and children's activity patterns. The concentration and bioaccessibility of pollutants in the corresponding soil particle size will also be analyzed based on the particle size distribution of hand dust. Finally, a new refined method and model for health risk assessment of human oral exposure to soil pollutants corrected by the hand dust particle size distribution and bioaccessibility will be established. The results can provide a new way of thinking for refined health risk assessment and have important significance for soil pollution risk control.