| (1)Single factor results of heavy metals in soil showed that the average contents of Cd,Pb,Cr,As,and Hg in the study area were 0.50,6.17,61.83,4.96,and 0.011 mg·kg-1,respectively.Compared with soil background values in Xinjiang,farmland soil Cd The average value of the contents exceeded the cadmium environmental background value of Xinjiang soil,and the exceeding standard rate was 100%.The average Cr content in farmland soils exceeded most of the chromium soil environmental background values in Xinjiang,exceeding the standard rate of 97.83%,and the Pb,As,and Hg elements in farmland soils.The average content did not exceed Xinjiang’s soil environmental background values.Compared with the national secondary standards for soil environmental quality standards（GB 15618-1995）（traditional standards）,the average Cd content of farmland soil is less than the secondary standard of the National Soil Environmental Quality Standard（0.6 mg·kg-1）.This is 41.3%.The contents of Pb,Cr,As,and Hg did not exceed the standard values of the traditional standards.The coefficient of variation of the five heavy metals is Hg>Cd>As>Cr>Pb,Pb belongs to weak variation,Pb belongs to weak variation,Cd,Cr,As belong to moderate variation,Hg belongs to strong variation.（2）The results of spatial distribution of heavy metals in soil showed that the spatial distribution of Cd and Hg content in farmland soil showed a decreasing trend from west to east and from south to north using Kriging interpolation method.The spatial distribution of the mean values of Pb,Cr,and As was from west to east,gradually increasing from south to north.（3）The results of soil organochlorine pesticides detection showed that the contents of four isomers（α-HCH,β-HCH,γ-HCH,andδ-HCH）of organochlorine pesticide HCH in farmland soil were all not All of the four isomers（p-p’-DDE、o,p’-DDT、p,p’-DDD、p,p’-DDT）of organochlorine pesticide DDT were detected.Organochlorine pesticides did not contaminate the farmland soil in the study area.（4）The results of farmland soil pollution risk assessment showed that the single factor potential ecological risk index of five heavy metals in farmland soil of Urho district of Karamay city was Cd>As>Hg>Cr>Pb compared with the traditional standards.The potential ecological risk index of Cd,Pb,Cr,As,and Hg in soil was low,and all the five heavy metals at the 46 sampling sites in the study area were all at a low potential ecological risk level.Among them,the potential ecological risk of Cd elements in farmland soil is the largest.There is a certain potential ecological risk for soil Cd at all sampling points.Divided by pollution levels are all security levels.In general,the risk of farmland soil pollution in the Urho district of Karamay city is controllable,and individual indicators are slightly higher.Heavy metal pollution in some areas cannot be taken lightly.The causes of heavy metal pollution in farmland soils are relatively complex,controlling the sources of pollutants,paying close attention to the regional changes in the risks in the study area,and protecting farmland soil ecological environmental quality has a major responsibility.Complete the soil remediation work in farmland as soon as possible to provide scientific basis for the in-depth development of pollution prevention and control projects,and provide scientific basis for improving the living environmentof residents and preventing the generation of environmental pollution diseases.Therefore,it is necessary to monitor long-term heavy metal elements in farmland soil. |
