Polycyclic aromatic hydrocarbons in urban soils of China: Distribution, influencing factors, health risk and regression prediction

Polycyclic aromatic hydrocarbons (PAHs) in urban soils are a risk to the health of residents. To predict those risks, the distribution and the factors influencing the concentration of PAHs were studied by collecting 1120 records of soil PAHs published during 2006-2017 from 26 cities. The mean concentrations of 16 PAHs (Sigma PAHs) in soil varied from 123 mu g/kg to 5568 mu g/kg, with a mean value of 1083 mu g/kg, suggesting that a few cities were polluted. The distribution of Sigma PAHs in the cities followed two gradients, namely from northern China through eastern China to southern China and from industrial cities through developed cities to cities that are main tourist attractions. The concentrations were significantly correlated to annual temperature, the efficiency of energy use, and to such measures of air quality as PM10 and NO2 concentrations. A regression equation developed to predict the concentration of Sigma PAHs in soil and the corresponding health risks to residents of 35 major Chinese cities of China showed that the risks to adults and children were slight in most cities but those in a few industrial cities were of concern, and field investigations are recommended to assess the risk in greater detail, The method offers a useful tool for predicting such risks in other cities even when data on soils PAHs are not available. (C) 2019 Elsevier Ltd. All rights reserved.