Endemic Heavy Metals Pollution Assessment and Its Distribution in Soil Profile in Kuitun Region

In the present study,heavy metals including Cd,As,Cu and Zn distribution in different layers of soil profile(0~20,20~40,40~60,60~80,80~100 cm) were determined.Two methods including single factor index and nemerow pollution index were employed to evaluate heavy metal pollution level based on heavy metal national quality standard GB15618-1995(Ⅱ).Our research area located in 123 state farm unit in Kuitun region,Xinjiang.The order of soil heavy metal pollution evaluated by single factor index method is CdAsCuZn,and by method of nemerow pollution index,pollution degree value already reached to 1.71,which means soil heavy metal pollution in researching area belonging to 3 grade.Moreover,from single pollution index order and heavy metal concentration in top layer of soil we can make a conclusion that soil heavy metal pollution occurred in 123 farm unit in Kuitun region is Cd-As compound pollution,the mainly source of heavy metal element is Cadmium,followed by Arsenic,however,elements of Cu and Zn haven't reached to pollution rate yet.Briefly,our research show soil heavy metal pollution in investigated area belongs to Cd-As compound pollution.Soil Cd and As contents have no statistically significant difference among different soil vertical depth,indicating soil parent material and underground water quality play a major role to soil Cd-As compound pollution in Kuitun region.