中国优控多环芳烃土壤污染特征及国内外生物可给性研究进展

多环芳烃(Polycyclic aromatic hydrocarbons,PAHs)是一类持久性有机污染物,容易在土壤中累积并且毒性显著,但PAHs在土壤固相上的吸附性较强,基于土壤污染总量暴露会导致高估人群健康风险。本研究基于2000-2020年间发表的123篇文献,总结了我国土壤中16种优先控制多环芳烃(∑16PAHs)的污染浓度分布和组成特征,介绍了11种常见的模拟PAHs生物可给性测试方法和主要影响因素,并总结了PAHs的生物可给性系数范围。研究结果表明土壤∑16PAHs最高与平均浓度分别为23 250 和1 314.7 μg.kg-1污染较为严重；近年来PAHs生物可给性测试方法主要基于生理原理提取法(PBET),在模拟消化过程和吸附剂等方面不断完善和改进,并且消化条件、土壤性质等因素对生物可给性结果影响较大。16种PAHs的生物可给性平均值范围为13.2%~72.4%,其中?和苯并[b]荧蒽的生物可给性较高,对∑16PAHs暴露产生贡献较高。本研究为开展土壤PAHs污染精细化风险评估研究提供重要理论参考依据。

Research Progress on Soil Pollution Characteristics in China and Bioaccessibilities of the Prioritized Polycyclic Aromatic Hydrocarbons at Home and Abroad

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants, which reaadily 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, indicating serious pollution. 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.