Characteristics and source identification of heavy metal pollution in shallow topsoil in Yinchuan City
To comprehensively assess the status of heavy metal contamination in the topsoil of a city in Northwest China,this study focused on the 0～2cm surface layer in Yinchuan City.The Single Factor Index,Nemerow Pollution Index,and Potential Ecological Risk Index were utilized to gauge heavy metal pollution and potential ecological hazards.The spatial distribution patterns of soil heavy metals were examined using the inverse distance weighted interpolation method.Correlation analysis and principal component analysis were employed to identify pollution sources.Subsequently,the research expanded to include an analysis of topsoil heavy metal contamination in several key cities across Northwest China,with a discussion on the regional implications of the findings.The study revealed that concentrations of Ni and Cr in Yinchuan's shallow topsoil were relatively low,whereas Cu,Pb,and Zn demonstrated varying levels of accumulation,with Cd exhibiting significant enrichment.The average values of Cr and Ni were lower than the background values of Ningxia soil,which were 0.95 and 0.73 times the background values,respectively.The average values of Cd,Cu,Pb,and Zn elements were higher than the background values of Ningxia soil,which were 1.70 times,1.00 times,1.08 times,and 1.09 times,respectively.The pollution levels,according to the Single Factor Index,were ranked as Cd＞Zn＞Pb＞Cu＞Cr＞Ni,and the average Nemerow Pollution Index indicated a mild pollution level.Ecological risk assessments showed minor risks associated with Cd,Cr,Cu,Ni,Pb,and Zn,and the comprehensive potential ecological risk index suggested an overall slight risk.In Yinchuan,shallow topsoil concentrations of Cr and Ni were predominantly originated from natural sources,while Cd,Cu,Pb,and Zn were mainly attributed to transportation and agricultural activities,with Cd also being impacted by industrial pollution.Heavy metals in urban soils across Northwest China exhibited some degree of enrichment,yet accumulation levels were not excessive,and the primary contributors were transportation,industry,and natural sources.The significant presence of Cd in the soils of Northwest China was concerning and warranted close scrutiny with respect to industrial,agricultural,and transportation developments.
heavy metals in soilpollution assessmentspatial distributionsource analysisNorthwest ChinaYinchuan City
万方数据
维普
