Elemental carbon components and PAHs in soils from different areas of the Yangtze River Delta region, China and their relationship

•PAHs were strongly associated with char-EC and soot-EC levels in high urbanization soils.•The source of EC and its components can represent the main source of PAHs in soils.•Quantitative equations for PAHs versus specific carbon types were built.•Quantitative relationship model of soil PAH distribution was constructed. Elemental carbon (EC) is a chemically heterogeneous class of carbonaceous particles—including char, soot, coke, charcoal, and others—that form by incomplete fossil fuel and biomass combustion. Many previous studies indicate that EC has a better correlation with polycyclic aromatic hydrocarbon (PAH) distribution in urban soils than total organic carbon (TOC). Nevertheless, the correlation between EC components and PAHs in developed regions is still not clear. Accordingly, we explored the concentrations, sources, and correlations of EC components with PAHs in soils from different areas of the Yangtze River Delta region, China. The results showed that soil EC and PAH levels were higher in Nanjing (high urbanization) than in Dingshu or Lujia (lower urbanization), yet TOC exhibited the opposite trend with respect to PAH levels. The main sources of both EC and PAHs were fossil fuel and biomass combustion, but there were differences between the study areas. The ∑16PAHs concentration was strongly associated with char-EC and soot-EC levels in Nanjing (P