Sources and cancer risks assessment of polycyclic aromatic hydrocarbons in particulate matter and surface soils in Kunming, China

The concentrations, possible sources and cancer risks of polycyclic aromatic hydrocarbons (PAHs) in fine particulate matter (PM2.5), total suspended particles (TSP) and surface soils collected from the same sampling spots were analysed in Kunming, China. The total PAH concentrations in PM2.5, TSP and surface soil were 7.44-25.64 ng/m3, 17.73-48.35 ng/m3 and 72.16-442.40 ng/g dry weight, respectively. Pyrogenic origins (especially coal, wood and fossil fuel combustion) were identified as the main sources of PAHs in particulate matter (PM) and surface soils based on the diagnostic ratios and principal component analysis (PCA). The values of incremental lifetime cancer risk (ILCRs) that exposed to PAHs in PM2.5 were slightly larger than 10−4, indicating high potential of carcinogenic risk. And the values of ILCRs showed that particle-bound PAHs with higher potential carcinogenic ability than soil PAHs. Moreover, compared with adults, the values of cancer risk among children were always higher.