Formation mechanism of soil PAH distribution: High and low urbanization

Abstract

Urbanization is an important driving force for the distribution of polycyclic aromatic hydrocarbons (PAHs) in urban soils. Research on factors affecting PAH distribution in urban soils has focused on analyses of statistical relationships, and quantitative models are not available in the literature. Accordingly, we chose the urban area of Nanjing (high urbanization), and Dingshu (low urbanization), and then comprehensively utilized soil sample test analyses, multivariate statistics, and other technical means to (1) study the concentration and sources of PAHs in urban soils, and (2) identify the main controlling factors that affect urban soil PAH distribution. We found that the population density and black carbon (BC) components were the critical factors of soil PAH distribution in Nanjing, yet BC components and leaf area index in Dingshu. We then constructed a quantitative relationship model of urban soil PAH distribution in different levels of urbanization. Using this model, we conducted a preliminary analysis of the formation mechanism of urban soil PAHs under different urbanization levels. This research provides a basis for finely controlling regional urban soil PAH pollution.