华中冶金工业走廊表层土壤、道路尘重金属污染特征及健康风险

Heavy metal pollution characteristics and health risks of topsoil and road dust in Central China Metallurgical Industry Corridor

于2015年1月,分别采集了316国道黄石-鄂州段表层土壤和道路尘样品各23个,采用火焰原子吸收分光光度法定量分析其重金属含量,以探讨重金属的污染特征及其健康风险.结果表明,Cu、Pb、Zn、Cd、Co、Cr、Ni、Mn的平均含量分别为97. 51、31. 18、115. 57、0. 58、21. 20、30. 10、37. 34、573. 74 mg·kg-1(表层土壤);730.12、236.23、392.74、6.20、223.72、90.54、148.42、4698.46 mg·kg-1(道路尘),且变异系数较大,污染分布不均匀.道路尘中重金属含量明显高于表层土壤,黄石段道路尘中重金属(除Cr、Ni、Mn外)明显高于鄂州段.地累积指数表明:表层土壤中Co及道路尘中Cd、Co、Mn污染最严重.由健康风险评价可知,表层土壤和道路尘中8种重金属非致癌风险为儿童>成人,其中手-口摄入为重金属暴露的主要途径,表层土壤中各种重金属暴露风险不大,而道路尘中Cr和Mn存在非致癌风险;表层土壤中Cd、Co、Ni、Cr均不存在致癌风险,道路尘的致癌风险主要来源于Cr.

In order to evaluate the pollution characteristics and health risk of heavy metals in topsoiland road dust around the Huangshi-Ezhou of G316 highway,23 topsoil and 23 road dust samples were collected in the studying area in January 2015. Heavy metal contents were determined by the flame atomic absorption spectrophotometry( FAAS). The results showed that the average concentrations of Cu,Pb,Zn,Cd,Co,Cr,Ni,Mn in topsoil and in road dust were 97.51,31.18,115.57,0.58,21.20,30.10,37.34,573.74 mg·kg-1and 730.12,236.23,392.74,6.20,223.72,90.54,148.42,4698. 46 mg·kg-1,respectively. All the observed levels in the dust samples were significantly higher than those in on the topsoil samples. And all the heavy metals( except Cr、Ni、Mn) in road dust of Huangshi section were significantly higher than those in the Ezhou section;The Geo-accumulation index showed that the pollution of Co in the topsoil and Cd,Co,Mn in road dust were the most serious. According to the health risk assessment,the non-carcinogenic risk of 8 heavy metals in topsoil and road dust is children > adults,in which the hand-mouth intake was the main way of heavy metals exposure. The exposure of various heavy metals in topsoil is not significant,but there is non-carcinogenic risk of Cr and Mn in road dust;Cd,Co,Ni,and Cr in the topsoil do not have carcinogenic risk,and the carcinogenic risk of road dust media mainly comes from Cr.