Distributing Characteristic And Pollution Evaluation Of Heavy Metals In Different Function Zones Of Baotou

Baotou is a typical heavy industrial city and the heavy metals which discharge invarious forms is threatening to the surrounding environment. In this study, Baotou wasdivided into5functional zones, and collected88soil samples, analyzed the content of Cu, Zn,Pb, Cd, Cr. The spatial distribution and correlation of heavy metals was analyzed and the heavymetalspollutionwasassessment bythe indexandpotentialecologicalrisk index. Theconclusi-onswerefollowing:(1)Except for Cr, the contents of Cu, Zn, Cd and Pb were more than the soil backgroundvalues of Inner Mongolia and had a high variability. It showed that they have been affectedby human activities in different degrees. The contents of heavy metals in different functionzones were different from each other. The content of Cd was industrial area>businessarea>science and education area>urban green space>residential areas, the content of Cu wasindustrial area>science and education area>residential areas>business area>urban green spaceand the content of Zn and Pb were industrial area>science and education area>residentialareas>urban green space>business area. The correlation analysis showed that it wassignificantly correlated to each other of5heavy metals in Baotou, and part of them insignificantly correlation between different heavy metals in different functional zones. Itindicatedthat thesources of5heavymetalsaresameorsimilar.(2)The results of single factor index method in Baotou showed that the most seriouslypolluted element was Cd among the5heavy metals, followed was Pb. Baotou was in seriouspollution of soil heavy metals. The pollution index of soil heavy metals in each function zonewas Cd>Pb>Cu>Zn>Cr, and Cd was heavy pollution in all function zones and Cr was all in aclean and safe condition. The pollution pattern of different heavy metals in all function zoneswas different. The pollution index of Cu was industrial area>residential areas>science andeducation area>business area>urban green space, the pollution degree of Zn and Cr wereindustrial district>science and education area>residential areas>urban green space>businessdistrict and the pollution index of Cd was industrial district>business district>science and education area>urban green space>residential areas. The Nemerow index of industrial area,science and education area, business area, residential areas and urban green space respectivelywas8.60,3.63,3.63,2.74,2.70. The pollution grade of them were heavy pollution, heavypollution,heavypollution,middle pollutionand middlepollution.(3)The results of potential ecological risk in all function zones were Cd>Pb>Cu>Cr>Znand Cd was in a middle potential harmful, other heavy metals were in slight potential harmful.The potential ecological risk index (RI) of Baotou was238.75, which belongs to middlepotential harmful. The potential ecological risk level of Cd in each function zone was more thanstrong potential ecological harmful and other heavy metals were in slight potential ecologicalharmful. The RI of industrial district, science and education zone, business district,residential areas and urban green space was47.72,162.62,161.47,123.95,120.98, thehazard degree of them was strong, middle, middle, slight and slight potential harmful.