Gao Yongfei, Zhu Jingxue, He An
College of Ecology, Taiyuan University of Technology, Taiyuan 030024, PR China.
Key Laboratory of Pollution Process and Environmental Criteria of Ministry of Education and Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China.
Water Res. 2022 Nov 1;226:119272. doi: 10.1016/j.watres.2022.119272. Epub 2022 Oct 19.
The presence of dissolved organic matter (DOM) strongly influences the bioavailability of metals in aquatic environments; however, the association between the binding activities and the concentrations of DOM compositions is not well documented, leading to uncertainties in metal toxicity assessment. We creatively quantify the mitigation and acceleration effects of DOM compositions on cadmium (Cd) bioaccumulation and toxicity in zebrafish larvae using abiotic ligand (ABLs) and biotic ligand (BLs) in a toxicokinetic-toxicodynamic (TK-TD) model. The BL-TK-TD model could accurately predict the protective effect of fulvic acid while overestimating the complexing capacity of citric acid. The model also could successfully simulate the protective effects of native DOM in most cases from 32 natural water bodies in China. The observed LC50 values of Cd showed a peak effect for the native DOM fraction comprising hydrophilic acidic contents (3.55 ± 0.44 mg L ) in natural water from 32 sites. The BL-TK-TD model provides practically useful information to identify the effect of different DOM compositions on metal bioavailability and toxicity in aquatic environments and guides future water management policies aimed at controlling aquatic heavy metal pollution.
溶解有机物（DOM）的存在强烈影响着水生环境中金属的生物可利用性；然而，DOM成分的结合活性与浓度之间的关联尚无充分记录，这导致了金属毒性评估的不确定性。我们创新性地使用非生物配体（ABLs）和生物配体（BLs），在毒代动力学-毒效动力学（TK-TD）模型中量化了DOM成分对斑马鱼幼体镉（Cd）生物累积和毒性的缓解与加速效应。BL-TK-TD模型能够准确预测富里酸的保护作用，同时高估了柠檬酸的络合能力。该模型在大多数情况下还能成功模拟中国32个天然水体中天然DOM的保护作用。在32个采样点的天然水体中，观察到的Cd半数致死浓度（LC50）值对包含亲水性酸性成分的天然DOM组分呈现出峰值效应（3.55±0.44 mg L ）。BL-TK-TD模型为识别不同DOM成分对水生环境中金属生物可利用性和毒性的影响提供了切实有用的信息，并为未来旨在控制水生重金属污染的水管理政策提供了指导。
