城市街道土壤重金属铅污染分布特征及评价——以贵阳市为例

随着中国社会发展和城市化的进程加快,城市街道重金属污染也越来越严重,对其研究为城市的健康发展有着重要的意义。通过对贵阳市城市街道土壤重金属铅污染进行了研究,结果表明:南明区街道土壤中铅的平均含量为145.37 mg.kg-1,为贵阳市土壤环境背景值的3.9倍,其它行政区街道土壤中铅的含量按金阳新区、花溪区、乌当区、小河区、云岩区、白云区顺序平均含量分别为61.09 mg.kg-1、103.67 mg.kg-1、105.47mg.kg-1、93.17 mg.kg-1、105.35 mg.kg-1、131.27 mg.kg-1,分别为贵阳市环境背景值的1.7倍、2.8倍、2.9倍、2.5倍、2.8倍、3.5倍数。不同行政区铅含量存在较大差异,而且铅在空间分布上也存在较大差异,其中金阳新区差异最大,小河区差异最小。采用地积累指数法及铅污染指数评价法表明:贵阳市城市道路土壤中铅污染市区外部大体上处于轻度污染水平,但市核心区和工业区处于偏中度至中度污染水平。

Distribution and Assessment of Lead Pollution in Urban Street Soil --A Case Study in Guiyang City

With the acceleration of China＇s social development and urbanization, heavy metal pollution in city streets is be- coming more serious. The research on city＇s healthy development is important. The lead pollution in urban street soil of Guiyang is studied. The results show that the average value of lead content in street soil is 145.37 mg·kg-1 in Nanming Distrct, which is 3.9 times of the soil background value in Guiyang. The average values of other districts are 61.09 mg·kg-1, 103.67 mg·kg-1 , 105.47 mg ·kg-1, 93. 17 mg·kg-1 , 105.35 mg·kg-1 and 131.27 mg·kg-1 , which are 1.7, 2. 8,2. 9,2. 5, 2. 8 and 3.5 times of the soil background value of Guiyang, respectively, recording the order of Jinyang New District, Huaxi, Wudang, Xiao- he, Yunyan and Baiyun. There is a big difference of lead content and spatial distribution in different districts. Among which Jin- yang New District shows the greatest difference, while Xiaohe District shows the smallest. The results of geo - accumulation index and lead pollution index evaluation show that the lead pollution in urban street soil of Guiyang is generally at light pollution level outside the city center, but city center and industrial areas are at light to middle even at middle pollution level.