PAH Pollution in Particulate Matter and Risk in Chinese Cities

In China, with the largest population and known as the world's factory, the study of air pollution trends can provide an important reference value for the world's population and manufacturing countries. In particular, the polycyclic aromatic hydrocarbon (PAH) pollution status in particulate matter can accurately reflect the dynamic balance between the atmosphere and sediments and the risks to people and ecology. This study combined 85 publications with over 6971 individual samples from 219 sites in 89 Chinese cities. The findings were first integrated into a unified database of the spatial distribution of the PAH concentration. The results revealed that the parent PAH concentration and pollution in atmospheric particulates greatly increased in Chinese cities (> 500 thousand people). The contamination levels, as indicated by the toxic equivalent quantity, incremental lifetime cancer risk, hazard index, and ecological risk, were higher in northern China (NC) than in southern China (SC). The health risk of subpopulations followed the cohort order of juveniles (≤ 18) < adults (> 18). The risk quotient and sediment quality guidelines showed that certain individual PAHs could occasionally pose an ecological risk in some cities, especially in NC. The results of the mean effect range median quotient suggested that the combined negative ecological effects of ∑16PAHs resulted in high (NC) and moderate (SC) risks. The ecological risk level in 73 cities in China was above the moderate level, which is mainly controlled by the source of coal for residential heating and heavy industry, automobile exhaust and light industries in NC and SC, respectively.