Research Progress on Soil Pollution Characteristics in China and Bioaccessibilities of the Priority-controlled Polycyclic Aromatic Hydrocarbons at Home and Abroad
Polycyclic aromatic hydrocarbons(PAHs)are a class of persistent organic pollutants,which readily accumulate in the soil with significant toxicity.However,PAHs could be strongly adsorbed by the solid phase of soil,the exposure based on the total pollution mass will lead to the overestimation of human health risks.Based on 123 papers published from 2000 to 2020,this study summarized the distribution and composition characteristics of soil concentrations of 16 priority-controlled PAHs(Σ16PAHs)in China,introduced 11 commonly used testing methods and main influencing factors for modelling bioaccessibilities,and summarized the ranges of bioaccessibility coefficients of PAHs.The results showed that the maximum and average concentrations of Σ16PAHs in soil were 23 250 and 1 314.7 μg·kg-1 respectively.In recent years,mainly based on the physiologically-based extraction tests(PBET),the bioaccessibility test methods of PAHs are continuously improved and modified in enriched simulation of digestion processes and adsorbents,while the digestion conditions and soil properties etc.have a great impact on the bioaccessibility results.The average bioaccessibilities of 16 PAHs ranged from 13.2% to 72.4%,among which higher values were identified for chrysene and benzo(b)fluoranthene,contributing significantly to the total Σ16PAHs exposure.This study therefore provided an important theoretical ground for undertaking detailed risk assessment of PAHs.