Fettweis Andreas, Bergen Benoit, Hansul Simon, De Schamphelaere Karel, Smolders Erik
Division of Soil and Water Management, KU Leuven, Heverlee, Belgium.
Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, Ghent, Belgium.
Environ Toxicol Chem. 2021 Jul;40(7):2015-2025. doi: 10.1002/etc.5034. Epub 2021 May 8.
Predicting metal sensitivities and metal mixture interactions for species within each trophic level is essential to understand the effects of metals at the ecosystem level. The present study was set up to explore the correlations of metal sensitivities among species and if these sensitivities or metal mixture interactions are related to growth or morphological traits. The toxicity of Ni, Cu, and Zn on algal growth was tested for 8 freshwater algal species when dosed singly and in combinations in phosphorus-limiting static systems. The metal sensitivities on specific growth rate (10% effect concentrations expressed as free ion activities) varied 2 to 3 orders of magnitude among species depending on metal. These sensitivities were unrelated (p > 0.05) to their specific growth rate (0.7-1.8 d ) or cell volume (10 -10 m cell ). Species-specific differences in one or more toxicokinetic and/or toxicodynamic (TKTD) processes are likely at the basis of this variation. The log-transformed metal sensitivities positively correlated (p < 0.1) among the species in all 3 binary combinations (Ni-Cu, Ni-Zn, and Cu-Zn), suggesting that species have correlated TKTD rates for these metals. Furthermore, they would also predict stronger effects of metal mixtures on algal community biodiversity than what would be expected without a positive correlation. Low-level metal mixture effects varied similarly, largely among species and mixture interactions that were highly variable: ranging from synergistic to antagonistic relative to independent action during exponential growth, whereas mixture interactions at 10% effect shifted toward additivity/synergism relative to concentration addition at carrying capacity. Some evidence was found for stronger synergistic mixture effects in smaller species. Overall, the present study highlights the importance of incorporating more species in sensitivity distributions and accounting for mixture toxicity in risk assessment. Environ Toxicol Chem 2021;40:2015-2025. © 2021 SETAC.
预测每个营养级内物种的金属敏感性和金属混合物相互作用对于理解金属在生态系统层面的影响至关重要。本研究旨在探索物种间金属敏感性的相关性，以及这些敏感性或金属混合物相互作用是否与生长或形态特征相关。在磷限制的静态系统中，对8种淡水藻类物种单独和组合添加镍、铜和锌时对藻类生长的毒性进行了测试。特定生长率的金属敏感性（以游离离子活性表示的10%效应浓度）因金属不同在物种间相差2至3个数量级。这些敏感性与它们的特定生长率（0.7 - 1.8 d⁻¹）或细胞体积（10⁻¹² - 10⁻⁹ m³/细胞）无关（p > 0.05）。这种变化可能基于一个或多个毒代动力学和/或毒效动力学（TKTD）过程中的物种特异性差异。在所有3种二元组合（镍 - 铜、镍 - 锌和铜 - 锌）中，物种间经对数转换的金属敏感性呈正相关（p < 0.1），表明物种对这些金属具有相关的TKTD速率。此外，与无正相关时预期的情况相比，他们还预测金属混合物对藻类群落生物多样性的影响更强。低水平金属混合物效应变化类似，主要在物种和混合物相互作用之间，这些相互作用高度可变：在指数生长期间相对于独立作用从协同到拮抗，而在10%效应时混合物相互作用相对于承载能力下的浓度加和转向加和/协同。在较小物种中发现了更强协同混合物效应的一些证据。总体而言，本研究强调了在敏感性分布中纳入更多物种以及在风险评估中考虑混合物毒性的重要性。《环境毒理学与化学》2021年；40:2015 - 2025。© 2021 SETAC。
