POPs污染场地土壤健康风险评价

Health Risk Assessment:Case Study of a Brownfield Contaminated by POPs at Changzhou

文章以常州市某化工厂为例,介绍了POPs污染场地的健康风险评价,分别对两种土地利用类型假设下土壤的3条暴露途径进行估算,重点考虑了儿童对污染土壤的敏感性,用年龄修正因子计算居民的致癌风险。结果表明两种假设下氯丹和灭蚁灵的致癌风险都超过了可接受的风险水平,在部分高暴露点甚至超过了目标风险值的100倍,需要对场地进行修复。各暴露途径对健康风险的贡献按从大到小排列依次为:直接摄入土壤﹥皮肤接触﹥呼吸摄入。文章还根据健康风险评价的公式反推出适合本污染场地的土壤初级修复目标分别为:氯丹5.2mg/kg、灭蚁灵7.4×10-1mg/kg(工业用地);氯丹1.6mg/kg、灭蚁灵2.7×10-1mg/kg(居住用地)。

Methodologies for health risk assessment （HRA） were applied in a brownfield on abandoned industrial site contaminated by persistent organic pollutants （POPs） at Changzhou, east China. For the defined future land use patterns, industrial （Ⅰ） and residential （Ⅱ） exposure scenarios were assumed and evaluated. HRA focused on 3 typical exposure pathways by soil, which was evaluated with regard to potential risks that may pose to humans, especially to children. Carcinogenic risks during the first 30 years of life were calculated using age-adjusted factors. Results of baseline risk assessment indicated that the potential health risk has exceeded the acceptable cancer risk. Risk from exposure via ingestion contributed most, which far outweighed the risk via inhalation. Preliminary remedial goals were calculated under the industrial scenario of 5.2 and 7.4×10^-1mg/kg for chlordane and mirex respectively while 1.6 and 2.7×10^-1mg/kg under the residential scenario.