兰州城市绿地SCCPs污染来源及人群健康风险

Sources identification and health risks of short-chain chlorinated paraffin in urban green spaces in Lanzhou,China

观测了2022~2023年暖、冷季节兰州市主城区绿化用地土壤中短链氯化石蜡(SCCPs)的污染水平、组成特征,并利用主成分分析法、多元线性回归方法对其污染来源进行了解析,运用熵值法进行生态风险评估,并利用暴露评估模型对人群健康暴露风险进行评价.结果表明研究区SCCPs浓度暖季节为19.67~938.15ng/g(平均296.00ng/g),冷季节为61.11~976.20ng/g(平均316.72ng/g),二者对应的氯含量分别为61.49%~64.62%和61.79%~64.21%.碳同系物以C10(35.80%和40.15%)、C11(24.80%和22.52%)为主,氯同系物以Cl7(30.08%和30.00%)、Cl_(8)(23.89%和24.44%)为主.来源解析显示污染可能来源于工业活动、污水处理厂废水和污泥的排放以及废水灌溉.生态风险评价表明土壤中的SCCPs不会对土壤生态造成重大危害,健康风险评价显示不论是儿童还是成人土壤SCCPs的暴露均低于每日可耐受摄入量(TDI).

Contamination characteristics of SCCPs in the soil of green land in the main urban area of Lanzhou city during the warm and cold seasons of 2022~2023 were observed,and the source assessment and identification were conducted using principal component analysis and multiple linear regression,the entropy value method was applied for the ecological risk assessment,and the health risk of the residents exposed to SCCPs was evaluated using the exposure assessment model.The concentrations of SCCPs in the study area ranged from 19.67 to 938.15ng/g(mean 296.00ng/g)during the warm season and from 61.11 to 976.20ng/g(mean 316.72ng/g)during the cold season,and the chlorine contents were 61.49%~64.62%and 61.79%~64.21%,respectively.C10(35.80%and 40.15%)and C11(24.80%and 22.52%)were the predominant carbon homologues,as well as Cl7(30.08%and 30.00%)and Cl_(8)(23.89%and 24.44%).The result of source apportionment showed that the contamination might be emitted from industrial activities,discharge of wastewater and sludge from sewage treatment plants and wastewater irrigation.The ecological risk assessment indicated that the levels of SCCPs in the soil did not cause a significant risk to soil ecology,and the health risk assessment showed that the health risk of the residents exposed to soil SCCPs was below the tolerable daily intake(TDI)for both children and adults.