Sources and Risk Assessment of Polycyclic Aromatic Hydrocarbons from the Urbanization Process of Topsoil

Abstract

To study the effects of urbanization on concentration, sources, and health risks of polycyclic aromatic hydrocarbons (PAHs), 95 topsoil samples were collected from Liaoning Province. For this assessment, 21 PAHs were analyzed via gas chromatography-mass spectrometry and discussed. The results show the total concentrations of the 21 PAHs in background, Shen-Fu, Shen-Yang, and Fu-Shun were 1496.76 μg·kg-1, 3000.50 μg·kg-1, 8705.11 μg·kg-1, and 8178.90 μg·kg-1, respectively, which is positively correlated with the urbanization levels. Diagnostic ratios and PMF modal analysis indicate that the sources of the PAHs in soils were most likely coal combustion and traffic combustion (petroleum combustion). The main sources of PAHs in the four areas were petrochemical combustion (41.0%), coal combustion (64.4%), traffic combustion (67.5%), and traffic combustion (62.0%), that is, with the urbanization process, human activity (mainly traffic combustion) gradually become the major contributor of PAHs to the environment. Health risk assessment showed that the risk of cancer exposure through soil digestion and skin exposure was higher. There is a higher health risk from PAHs in urban soils, and the health risks associated with children and adolescents are greater than with other residents, requiring more attention.