Faculty of Bioscience Engineering, Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, Ghent, Belgium.
Environ Toxicol Chem. 2018 Feb;37(2):587-598. doi: 10.1002/etc.3999. Epub 2017 Dec 11.
Freshwater biota are usually exposed to mixtures of different metals in the environment, which raises concern because risk-assessment procedures for metals are still mainly based on single-metal toxicity. Because microalgae are primary producers and therefore at the base of the food web, it is of utmost importance to understand the effects of metal mixtures on these organisms. Most studies that have investigated the combined interactive effects of mixtures on microalgae performed tests in only one specific water. The objective of the present study was to test if combined effects of mixtures to Pseudokirchneriella subcapitata were the same or different across natural waters showing diverse water-chemistry characteristics. This was done by performing experiments with ternary Cu-Ni-Zn mixtures in 3 natural waters and with binary Cu-Ni mixtures in 5 natural waters. We showed that the ternary mixture acted noninteractively on algal growth, except in one water in which the mixture acted antagonistically. We suggest that a low-cationic competition situation in the latter water could be the reason for the antagonistic interaction between the metals. On the other hand, the binary mixture acted noninteractively on algal growth in all tested waters. We showed that both the concentration addition and independent action models can serve as accurate models for toxicity of ternary Cu-Ni-Zn and binary Cu-Ni mixtures to P. subcapitata in most cases and as protective models in all cases. In addition, we developed a metal mixture bioavailability model, by combining the independent action model and the single-metal bioavailability models, that can be used to predict Cu-Ni-Zn and Cu-Ni toxicity to P. subcapitata as a function of metal concentration and water characteristics. Environ Toxicol Chem 2018;37:587-598. © 2017 SETAC.
淡水生物群通常暴露于环境中的多种不同金属混合物中，这引起了人们的关注，因为金属的风险评估程序仍然主要基于单一金属毒性。由于微藻是初级生产者，因此处于食物网的基础，因此了解金属混合物对这些生物的影响至关重要。大多数研究混合对微藻的联合交互作用的研究仅在一种特定的水中进行了测试。本研究的目的是检验混合物对拟菱形藻的联合效应是否在具有不同水化学特性的天然水中相同或不同。这是通过在 3 种天然水中进行三元 Cu-Ni-Zn 混合物实验和在 5 种天然水中进行二元 Cu-Ni 混合物实验来完成的。我们表明，三元混合物对藻类生长的作用是非交互的，除了在一种水中外，该混合物具有拮抗作用。我们认为，在后一种水中，阳离子竞争较弱可能是金属之间拮抗相互作用的原因。另一方面，二元混合物在所有测试的水中对藻类生长的作用是非交互的。我们表明，浓度加和独立作用模型都可以作为准确的模型，用于预测三元 Cu-Ni-Zn 和二元 Cu-Ni 混合物对拟菱形藻的毒性，在大多数情况下可以作为保护模型。此外，我们通过结合独立作用模型和单一金属生物利用模型，开发了一种金属混合物生物利用度模型，该模型可用于预测 Cu-Ni-Zn 和 Cu-Ni 对拟菱形藻的毒性，作为金属浓度和水特性的函数。Environ Toxicol Chem 2018;37:587-598。©2017 SETAC。
