我国表层土壤多环芳烃含量的空间分布及成因

Spatial Distribution and Genesis of Polycyclic Aromatic Hydrocarbons (PAHs) in the Surface Soil in China

为全面了解我国表层土壤多环芳烃(PAHs)含量状况及空间分布,收集整理了1999—2018年发表的208篇有关全国各地表层土壤PAHs的文献,综合运用ArcGIS空间插值技术、地理探测器模型和统计学方法,定量分析了我国表层土壤PAHs含量、空间分布、主要来源及成因。结果表明:我国各地表土PAHs平均含量的空间分布具有明显的区域特征,从华北、东北、华东、中南、西北到西南地区依次递减,华北地区土壤Σ16PAHs平均含量约为西南地区的2.5倍;我国土壤PAHs含量总体上处于中低污染水平,中等污染、轻微污染和未污染土壤占比分别约为22.6%、71.1%和6.3%。利用地理探测器对9种社会经济影响因素的定量分析表明,燃煤发电对PAHs含量的空间分布格局影响显著高于其他因子;主成分分析结果也表明燃煤是重要污染源之一。该研究对实现我国土壤PAHs的科学管控和防治具有一定参考价值。

In order to comprehensively understand the concentrations and spatial distribution of polycyclic aromatic hydrocarbons in surface soils in China,208 literatures published from 1999 to 2018 on PAHs in the surface soils were collected for data extraction and in-depth analysis.ArcGIS spatial interpolation technique,geographic detector model and statistical method were used to quantitatively analyze the concentration,spatial distribution,main sources,and affecting factors of PAHs in the surface soil in China.The results show that the spatial distribution of PAHs in the surface soil has obvious spatial variation.The PAHs concentrations follow a significant decreasing trend of north China>northeast China>east China>mid-south China>northwest China>southwest China.The average concentration of 16 USEPA priority PAHs in north China is about 2.5 times that of southwest China.The PAHs pollution level in the surface soils in China generally ranged from low to medium according to Maliszewska-Kordybach′s classification standard.The moderately polluted,slightly polluted,and uncontaminated soil accounted for approximately 22.6%,71.1%and 6.3%,respectively.Quantitative analysis of nine socio-economic factors by using geo-detector model shows coal-fired power generation is the most significant factor on PAHs spatial distribution compared with the other factors.Principal component analysis also indicates that the coal combustion is the important pollution source,in consistent with the result of geo-detector model.This study has certain reference value for the prevention and scientific control of PAHs pollution in the surface soil in China.