Levels, sources, and risk assessment of PAHs residues in soil and plants in urban parks of Northwest China

Using eight typical parks in Urumqi in Northwest China as the study area, we detected the content of polycyclic aromatic hydrocarbons (PAHs) in park topsoil and 10 common plants in the park during different seasons. The results showed that the content of PAHs in park soil in the summer was 5–6 times that in the winter, and the monomer PAHs in some park soil sampling points were higher than the soil pollution risk screening value. Compared with other areas, pollution is more serious. In summer, the plants with high PAHs content in leaves are short herbs, while in winter, they are tall arbors. The composition of park soil PAHs is mainly from the source of the HMW as the source of traffic. The proportion of the LMW in the winter was significantly higher than that in the summer. The source of plants in the summer is similar to that of the soil; whereas the source of plants in the winter is more complicated. The TEQ values of soil PAHs in South Park, Zhiwu Park, Shihua Park and Toutunhe Park were higher. The NIPI values of some sampling points in these four parks in the summer were relatively high. The average ILCRs of adults and children in all parks reached a low-risk level in summer. The carcinogenic risk in children is much higher than that of adults.