Status, sources, and human health risk assessment of PAHs via foliar dust from different functional areas in Nanjing, China.

The present study was carried out to assess and understand the potential health risk, level of contamination, composition pattern, and sources of urban foliar dust in Nanjing City with respect to polycyclic aromatic hydrocarbons (PAHs). Five urban functional areas of foliar dust were analysed and the contents of 16 priority PAHs were determined. Total PAH concentrations in foliar dust ranged from 1.77 to 19.02 μg·g⁻¹, with an average value of 6.98 μg·g⁻¹. The PAH pattern was dominated by four and five-ring PAHs (contributing > 38% of total PAHs) in all of the five functional areas. The results indicated that the combustion of fossil fuel, coal, and biomass, as well as vehicle traffic emissions were the major sources of PAHs. The estimated incremental lifetime cancer risk due to PAHs in foliar dust were 8.19 × 10⁻⁶, 6.63 × 10⁻⁶, and 9.65 × 10⁻⁶ for childhood, adolescence and adulthood, respectively, indicating a high risk of cancer from exposure to foliar dust in Nanjing. Our results indicated that foliar dust might be a useful indicator of atmospheric PAH pollution. [ABSTRACT FROM AUTHOR]