贵阳市区地表灰尘重金属污染分析与评价

Pollution analysis and evaluation of heavy metals in urban dust in Guiyang

以贵阳市区为研究地点,采集了贵阳城区工业区、交通区、商业区、居民区、文教区、公园广场、对照区7个类别共80个采样点的地表灰尘,分析了地表灰尘重金属在不同区域的分布特征,并分析其可能来源。最后,应用潜在生态危害指数法对6个功能区（工业区、交通区、商业区、居民区、文教区、公共区）样品中重金属的潜在生态危害进行评价。结果表明：贵阳市地表灰尘重金属的平均质量分数均高于贵州省土壤环境背景值,Cd、As、Cu污染质量分数都超过4倍以上背景值水平,其余重金属污染水平大多处于1~3倍背景值水平。就单个重金属潜在生态危害系数平均值来看,地表灰尘的潜在生态危害最大的是Hg,其次是Cd,生态危害最低的是Cr。6个功能区生态危害水平均属于强生态危害水平,其中工业区和公共区生态危害水平最高。

This study focused on characterization of heavy metals in the dust of the city of Guiyang.80 surfacial dust samples were collected from 7 land-use types,such as industrial area,traffic area,commercial area,residential area,cultural and educational area,public and square area,as well as contrast area.Distribution characterization and possible sources of heavy metals of Hg,Cd,As,Pb,Cr,Cu,Ni and Zn were analysised.Potential ecological risk index was adopted to estimate the potential ecological risk of 6 land-use types（traffic areas,industrial area,commercial areas,residential area,cultural and educational area,public and square area）.The results showed that the average concentration of heavy metals in the dust exceeded the soil background value in Guizhou.Cd,As,Cu were 4 times of the soil background value in Guizhou,the other heavy metals were 1-3 times of the soil background value.Based on the calculation results of heavy metal ecological risk index in street surface dust of Guiyang,potential ecological risk of Hg was the highest,Cd was moderate and Cr was the least.Potential ecological risk of 6 land-use reached the strong ecological risk levels,industrial area and public area reached the highest.