Polycyclic Aromatic Hydrocarbons in Urban Soils of Zhengzhou City, China: Occurrence, Source and Human Health Evaluation

Increasing contamination of urban soil by persistent organic pollutants is a major environmental issue. The purpose of the present study was to investigate the distribution, source and human health risk of polycyclic aromatic hydrocarbons (PAHs) in different functional areas in Zhengzhou City, China. Total 130 soil samples were collected from surface layer (0–10 cm) in urban road, overpass, residential area and park in the city during January 2019. Concentrations of ∑PAH16 in the urban soil ranged from 49.90 to 11,565 µg kg−1 and seven carcinogenic PAHs accounted for 69% of the total PAHs. The mean concentrations of PAHs decreased in the following order: urban road > overpass > residential area > park. Analysis based on diagnostic rate demonstrated that PAHs mainly originated from pyrolysis sources including traffic emissions and combustion of coal and biomass. Health risk assessment indicated that PAHs in urban road in the city have potential carcinogenic risks to residents. The present study suggested that the control of urban PAHs pollution in Zhengzhou City should be strengthened.