Distribution Characteristics Of Heavy Metal In Soil Of Different Land Use Types In Jiaozuo City

In this paper,Jiaozuo City was selected as the study area,and the surface soil of different land use types(Zhongzhan Industrial area,Macun Industrial area,urban living land,and agricultural land)in Jiaozuo City was selected as the research object.A total of 51 surface soil samples were collected.The contents,spatial distribution characteristics,pollution characteristics,accumulation degree,ecological risk and health risk level characteristics of heavy metal in soil of three different land use types(industrial land,urban living land,agricultural land)in Jiaozuo City were analyzed and compared.The conclusions are as follows:(1)According to the content and spatial distribution characteristics of heavy metal,the average contents of As,Cr,Cu,Pb,Ni and Zn in the soil of the study area were 35.63,77.16,28.61,27.18,25.83 and 74.83 mg/kg,respectively.The average contents of As,Cu,Pb and Zn were industrial land > urban living land > agricultural land,and the average content of Ni was urban living land > industrial land(Macun Industrial area > Zhongzhan Industrial area)> agricultural land.The average content of Cr was in the order of Zhongzhan industrial area > urban living land > Macun industrial area > agricultural land.(2)The results of single factor pollution index analysis showed that Cu,Pb,Ni and Zn in the three types of land soils did not exceed the standard,and As and Cr exceeded the standard.The maximum pollution index of As from large to small was:urban living land > agricultural land > Zhongzhan industrial area > Macun industrial area.The maximum pollution index of Cr from large to small was as follows:Zhongzhan Industrial area > Macun Industrial area > urban living land > agricultural land.From the point of pollution degree,the proportion of mild and above pollution caused by As was as follows: urban living land > agricultural land > Macun industrial area > Zhongzhan industrial area.The proportion of mild and above pollution caused by Cr was as follows: Zhongzhan industrial area > urban living land > Macun industrial area > agricultural land.(3)The results of comprehensive pollution index analysis showed that the soil of three land use types in the study area exceeded the standard,and the pollution degree was as follows: Zhongzhan industrial area > urban living land > agricultural land >Macun industrial area.The range of pollution was as follows: urban living land >Zhongzhan industrial area > agricultural land(the exceeding standard rate of Macun industrial area was 0),and the main pollution factors were As and Cr.(4)In the three land use types of soil in the study area,the accumulation degree of As was greater than the other five heavy metals,and the accumulation degree was as follows: industrial land,agricultural land and urban living land.Cr and Ni only accumulated in the Zhongzhan industrial area.Zn reached a moderate accumulation degree in the soil of some sampling points in the Zhongzhan industrial area.Pb accumulated locally in industrial land and urban living land,and Cu slightly accumulated in industrial land,urban living land and agricultural land.Compared with other cities in China,the accumulation of As in the study area was significantly higher than that in most cities.(5)The results of potential ecological risk analysis showed that only As had medium risk level in four land types,and the proportion of medium risk level points was: Macun industrial area > Zhongzhan industrial area > urban living land >agricultural land.The influence degree on the comprehensive non-carcinogenic health risk of adults is in the order of Zhongzhan industrial area > Macun industrial area >urban living land > agricultural land,and the influence degree on the comprehensive non-carcinogenic health risk of children is in the order of Zhongzhan industrial area >Macun industrial area > urban living land > agricultural land.The carcinogenic health risks for adults and children are in the order of Zhongzhan industrial area > Macun industrial area > urban living land > agricultural land.The carcinogenic health risks for adults and children in Zhongzhan Industrial area and children in Macun Industrial Zone exceed the recommended standards in China,and there are certain carcinogenic health risks that should be paid attention to.