不同毒性评估模型用于变电站场地土壤中多环芳烃健康风险评价比较

COMPARATIVE STUDY OF DIFFERENT TOXICITY EVALUATION MODELS ON HEALTH RISK ASSESSMENT OF PAHS IN SOIL OF TYPICAL SUBSTATION SITES

对衡水地区9座变电站场地土壤中16种优先控制的多环芳烃(PAHs)含量进行了检测和分析,并采用场地健康风险评价方法,对比了基于苯并[a]芘(BaP)的毒性评估模型和基于致癌斜率因子(非致癌参考剂量)的健康风险评估模型。结果显示:变电站场地土壤中PAHs总量在126.89-1181.94μg/kg, 7种致癌PAHs含量在60.07-698.5μg/kg,污染水平表明,轻微或无污染变电站占比达到66.7%,中度污染水平以上变电站占比为33.3%。2种评估模型均显示部分变电站存在致癌风险,经口摄入和皮肤接触暴露途径是致癌风险的主要暴露途径,累积贡献率高达91%以上。2种模型得出土壤总非致癌风险熵均小于可接受非致癌风险熵,且基于BaP的毒性评估模型会导致风险熵偏小,不适合非致癌物质的风险评价。从环境风险控制角度,认为基于致癌斜率因子(非致癌参考剂量)的健康风险评估模型对污染土壤的健康风险评估较为适宜。

The concentrations of 16 priority PAHs in soil of 9 substations in Hengshui, Heibei province were detected and analyzed. Health risk assessment method for contaminated site was used to compare the health risk based on BaP carcinogenic slope factor and carcinogenic slope factor(non-carcinogenic reference dose). The results showed that the total amount of PAHs in the soil of the substation site ranged from 126.89 μg/kg to 1181.94 μg/kg, and the contents of seven carcinogenic PAHs ranged from 60.07 μg/kg to 698.5 μg/kg. The pollution level showed that the substation with mild or no pollution accounted for 66.7%, and the substation with moderate pollution level or above accounted for 33.3%. Both models showed that some of the substations had carcinogenic risk, and oral ingestion and skin contact exposure were the main ways of exposure to carcinogenic risk, with cumulative contribution rate of 91% above. The results of the two models showed that the total non-carcinogenic risk quotient of soil was smaller than the acceptable non-carcinogenic risk quotient, and the BAP toxicity assessment model would lead to a small risk quotient, which was not suitable for the risk assessment of non-carcinogenic substances. From the perspective of environmental risk control, it was considered that the health risk assessment model based on carcinogenic slope factor(non-carcinogenic reference dose) was more suitable for the health risk assessment of the contaminated soil.