Geochemical Characteristics,Pollution Assessment,and Source Apportionment of Heavy Metals in Soils of Typical Urban Areas
To explore the distinctive features and ecological hazards associated with heavy metal contamination in urban terrains,a comprehensive survey was conducted involving the collection of 4 432 surface soil samples from Lanshan District,Linyi City,Shandong Province.The analysis encompassed the quantification of heavy metal constituents alongside the deter-mination of pH levels.Utilizing geostatistical techniques,the geo-accumulation index(Igeo)and the potential ecological risk index(RI)were calculated.These methodologies enabled a detailed examination of the geochemical attributes and pollution intensities of the soil's heavy metal content.To elucidate the origins of soil heavy metals within the study area,both the abso-lute principal component scores-multiple linear regression(APCS-MLR)model and positive matrix factorization(PMF)model were employed for comprehensive analysis.The outcomes revealed that the average concentrations of Cr,Ni,Cu,Zn,Cd,Pb,As,and Hg in the study area were 60.90,27.90,24.30,69.60,0.15,33.80,7.20,and 0.045 6 mg/kg,respectively.The order of variation among these elements was as Hg＞Pb＞Cu＞Cd＞Zn＞As＞Ni＞Cr.Based on the analysis conducted by the Igeo,it was found that there were 75,30,and 29 sampling sites where Hg,Pb,and Cd pollution reached moderate to severe levels,re-spectively.This signifies the presence of significant point-source pollution.The average RI calculated was 130.89,suggesting a moderate ecological risk.Specifically,Hg contributed 49.74％and Cd contributed 26.67％to the overall risk,highlighting these two elements as the primary ecological risk factors within the study area.The APCS-MLR and PMF models uniformly pinpointed the origins of heavy metals in the study area.Cr and Ni were sourced from natural geological processes,Cu and Zn were traced back to industrial activities,Cd and Pb were linked to transportation-related emissions,As had contributions from both natural and mining activities,and Hg was found to have been deposited from atmospheric sources.In summary,human in-terventions have significantly shaped the spatial distribution of heavy metals within the soil of study area.While the overall soil environmental quality in this region appears to be relatively satisfactory,it is imperative to closely monitor and manage the potential ecological hazards posed by Hg and Cd pollution due to their adverse impacts on the ecosystem.
soilheavy metalsgeochemical characteristicspollution assessmentsource apportionmentLanshan District,Linyi City
万方数据
维普
