Polycyclic Aromatic Hydrocarbons (PAHs) in Urban Street Dust of Huanggang, Central China: Status, Sources and Human Health Risk Assessment

Twenty-one street dust samples were collected in Huanggang City, Hubei Province, Central China Sixteen priority polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography-mass spectrometry (GC-MS). Concentrations of Sigma(16)PAHs ranged from 622.97 mu g kg(-1) to 4340.67 mu g kg(-1) with an average of 1862.10 mu g kg(-1). Among these PAHs, high-molecular-weight PAHs (four to six rings), which are the predominant PAH contributors in street dust, accounted for 55%-73% of the total PAHs. Mean concentrations of the PAHs among the four functional districts followed the order: education district > traffic area > business district > residential area. However, the individual PAH concentrations exhibited weak correlations with the total organic carbon. Based on the isomer ratios of the PAHs, biomass and coal combustion, and petroleum input were two key factors controlling PAH levels in this study. At a 95% confidence interval, the total incremental lifetime cancer risks for children, adolescents and adults approximated 10(-6)-1.5 x 10(-5).These values were higher than the baseline value for acceptable risk (10(-6)), indicating a potential carcinogenic risk.