安庆市降尘重金属的污染评价与健康风险评价

为探究安庆市降尘重金属污染程度及存在的健康风险,在市区设置48个采样点采集降尘,分析降尘重金属含量.结果表明:安庆市降尘中Cu, Zn, Pb, Ni, Cr, As, Cd含量平均值分别为134.1,640,128.9,55.4,128.7,63.9,2.98mg/kg.富集因子分析显示:Ni和Cr为轻微富集,Cu, Pb, As的富集因子较高,Zn和Cd为极强富集,其富集指数分别达到10.25和29.53.地积累指数评价平均生态危害表明:Cr和Ni属于轻度污染,Cu, Pb,As处于偏中度污染到中度污染之间,Zn属于中度污染,部分地区达到重度污染,Cd处于重污染到严重污染之间,其平均污染指数为5.07属于严重污染.手-口途径摄入是降尘重金属引起非致癌风险的最主要途径 ,总非致癌风险次序为As > Cr > Pb > Cu > Cd > Ni > Zn,其中手-口途径儿童As的暴露风险HQing已达到2.72明显超出限值1,易对儿童健康造成危害.其他金属风险均低于限值,不会对人们身体健康造成危害.降尘中的Ni, Cr, As, Cd通过呼吸途径不具有致癌风险.

Pollution evaluation and health risk assessment of heavy metals from atmospheric deposition in Anqing

In order to evaluate the contamination and health risk of heavy metals from atmospheric deposition in Anqing, samples of atmospheric deposition were collected from 48sampling sites respectively and their concentrations of heavy metals were determined. The results showed that the average contents of Cu, Zn, Pb, Ni, Cr, As, Cd were 134.1, 640, 128.9, 55.4, 128.7, 63.9, 2.98mg/kg, respectively. According to the results, the enrichment factor score of Ni, Cr was close to 1, belonged to slightly enriched, while the enrichment of Cu, Pb, As was more serious, and Zn, Cd were extremely enriched, each enrichment factors were reach 10.25 and 29.53. The assessment results of geo-accumulation index of potential ecological risk indicated that the pollution of Cd in the atmospheric deposition of Anqing was classified as extreme degree and the average geo-accumulation index was 5.07, and that of Cu, Pb, As were between moderate and extreme degrees, and Ni, Cr as slightly uncontaminated, and Zn belonged to moderate pollution, some areas reach serious pollution. Health risk assessment indicated that the heavy metals in atmospheric deposition were mainly ingested by human bodies through hand-mouth ingestion. The order of non-cancer hazard indexes of heavy metals was As > Cr > Pb > Cu > Cd > Ni > Zn. The hand-mouth ingestion of As has reached 2.72 significantly exceeded the limits 1, easy to affect children's health. Other metals didn’t exceed the limit of risk, and were not harmful for people's health. Elements such as Ni, Cr, As, Cd content in dust do not cause any cancer risk by inhalation.