兰州市室内积尘重金属污染评价

Pollution Evaluation and Health Risk Assessment of Heavy Metals from Indoor Dust in Lanzhou City

为探究兰州市室内积尘中重金属的污染程度及存在的健康风险,在兰州市城关区和榆中县的居民住宅设置了85个采样点采集室内积尘,分别分析了积尘中重金属的含量及对人体存在的健康风险。结果表明,兰州市室内积尘中重金属含量均显著高于甘肃省土壤背景值,已受到了一定程度的重金属污染。健康风险评价结果表明,儿童暴露于室内积尘重金属产生的致癌风险与非致癌风险均高于成人。除As外,其余4种重金属的非致癌风险处于可以接受水平以内;经口摄入是积尘重金属(Pb、Cd、As和Cr)引起非致癌风险的最主要途径,对Hg而言,Hg蒸汽吸入是其主要的暴露途径。室内积尘中Pb、Cd的致癌风险均低于安全阈值,表明兰州市室内积尘中的Pb、Cd对于儿童和成人均没有致癌风险。元素As对于成人和儿童的致癌风险分别为2.92E-05、4.13E-05,虽未超过最大可接受致癌风险水平10-4,但也高于了最低风险可接受水平10-6,应引起高度关注。

In order to evaluate the contamination and health risk of heavy metals from indoor dust in Lanzhou city, samples of indoor dust were collected from 85 sampling sites respectively and their concentrations and health risks of heavy metals were determined. The results indicated that the mean concentration in indoor dust were higher than their corresponding background values of Gansu soil. The results of health risk assessment showed that the children’s exposure dose, non-carcinogenic and carcinogenic risks of heavy metals in indoor dust were higher than those of adults. The non-carcinogenic risks were below the acceptable level, except As. Hand-to-mouth ingestion was the main pathway to indoor dust(Pb, Cd, As and Cr) for children and adults, But for Hg, the Hg steam inhalation was the main pathway. The carcinogenic risks of Pb, Cd in indoor dust within the safety threshold, showed that Pb, Cd in indoor dust to children and adults without the carcinogenic risk. Cancer risk from exposure to As of children and adults were 2.92 E-05, 4.13 E-05 respectively. Which was less than the risk limit of 10-4, however the risks were more than the risk limit of 10-6. the indoor dust should be paid more attention by the public.