He Yan, Meng Wei, Xu Jian, Zhang Yuan, Guo Changsheng
College of Water Sciences, Beijing Normal University, Beijing, 100012, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
Environ Monit Assess. 2016 Mar;188(3):193. doi: 10.1007/s10661-016-5201-y. Epub 2016 Feb 26.
The distribution and potential toxicity of polycyclic aromatic hydrocarbons (PAHs) in the sediments of Liaohe River Basin were investigated in this study. Total concentrations of 16 PAHs (∑PAH16) ranged from 82.5 to 25374.4 μg/kg averaging 3149.2 μg/kg. Three predominant PAHs were fluoranthene, phenanthrene, and pyrene. In Liao River, two-to-three-ring PAHs were dominant taking up 67.2-92.5% of ∑PAH16, whereas sediments in Daliao River system mainly contained four-to-six-ring PAHs ranging from 47.8 to 83.7%. Both petrogenic and pyrogenic sources contributed to the PAH pollution based on diagnostic ratios. The empirical and mechanistic sediment quality guidelines were used to estimate the toxicity risk of PAHs to benthic organisms. The ∑PAH16 in all sediments were significantly lower than probable effect concentrations (PEC), while ∑PAH16 at nine sites of the Daliao River system were between threshold effect concentrations (TEC) and PEC, suggesting that adverse effects were possible at the nine sites. The only individual PAH was acenaphthene whose concentrations were above PEC at some sites, indicating its potential toxicity. Based upon equilibrium partitioning theory and narcosis model, the obtained toxic units for PAH mixtures at all sites were far less than one, implying that the levels of PAH mixtures were acceptable for the protection of benthic fauna. The two evaluation methods lead to the consistent results that benthic organisms inhabiting in the sediments of Liaohe River Basin have no or low risk of adverse effects resulting from exposure to PAHs.
本研究调查了辽河流域沉积物中多环芳烃（PAHs）的分布及潜在毒性。16种PAHs的总浓度（∑PAH16）范围为82.5至25374.4μg/kg，平均为3149.2μg/kg。三种主要的PAHs为荧蒽、菲和芘。在辽河，两至三环PAHs占主导地位，占∑PAH16的67.2 - 92.5%，而大辽河水系沉积物主要含有四至六环PAHs，占比范围为47.8至83.7%。基于诊断比值，成岩源和热解源均对PAH污染有贡献。采用经验性和机制性沉积物质量准则来评估PAHs对底栖生物的毒性风险。所有沉积物中的∑PAH16均显著低于可能效应浓度（PEC），而大辽河水系9个位点的∑PAH16介于阈值效应浓度（TEC）和PEC之间，表明这9个位点可能存在不利影响。唯一浓度在某些位点高于PEC的单体PAH是苊，表明其具有潜在毒性。基于平衡分配理论和麻醉模型，所有位点PAH混合物的毒性单位远小于1，这意味着PAH混合物水平对底栖动物的保护而言是可接受的。两种评估方法得出一致结果，即栖息在辽河流域沉积物中的底栖生物因接触PAHs而产生不利影响的风险不存在或很低。
