土壤环境质量指导值与标准研究Ⅳ.保护人体健康的土壤苯并[a]芘的临界浓度

STUDY ON SOIL ENVIRONMENTAL QUALITY GUIDELINES AND STANDARDS Ⅳ.SOIL BENZO[A]PYRENE THRESHOLD CONCENTRATIONS BASED ON HUMAN HEALTH RISK ASSESSMENT

基于人体健康风险评估制定土壤环境质量指导值或标准是当前国际上广泛采用的方法。本文全面调研了国际上保护人体健康的土壤苯并[a]芘(B[a]P)的各类临界浓度,初步确定了量化土壤中B[a]P暴露剂量的暴露场景和暴露参数,率先提出了制定我国土壤中保护人体健康的B[a]P临界浓度的方法体系,这种方法可用来制定持久性有机污染物的土壤临界浓度。考虑了口腔摄入、皮肤接触、呼吸摄入和取食污染蔬菜摄入四个主要暴露途径,探讨了B[a]P的致癌风险水平为10-5或10-6时,农业用地、居住用地和工业用地方式下土壤中B[a]P的临界浓度,同时制定了保护地下水的土壤B[a]P的临界浓度。

Human health risk assessment has been extensively employed to derive guidelines/standards for soil environmental quality around the world. Various threshold values for Bezo[ a] pyrene （B [ a] P） concentration in soil for protection of human health were introduced. Exposure scenarios and parameters of three different patterns of land use were defined to quantify health risk of human exposure to soil B[ a]P. A human-health-based methodology for deriving threshold values for B[ a]P concentration in soils was proposed for the first time in China, which should be further used to derive threshold concentrations for other persistent organic pollutants. Four exposure pathways, i. e. soil ingestion, dermal contact, soil inhalation, and consumption of contaminated vegetables, were considered in modeling for calculation. Threshold concentrations of B [ a] P at cancer risk levels of 10^-5 and 10^-6,were calculated for agricultural,residential and industrial soils, respectively. Threshold values for B[a]P concentration in soil for protection of groundwater quality were also derived based on the guidelines/standards for protection of groundwater quality.