Department of Ecology, University of Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria.
Department of Ecology, University of Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria.
Sci Total Environ. 2019 Dec 20;697:134194. doi: 10.1016/j.scitotenv.2019.134194. Epub 2019 Aug 30.
Plastic contamination is an environmental problem spreading to even the most remote aquatic and terrestrial habitats and in particular, microplastics represent an uncertain threat for organisms. Microplastics can have a direct negative effect, but they can also potentially modify the toxicity and bioavailability of pollutants. Here, we tested over 1 week the combined effect of three different glyphosate chemical formulations (glyphosate acid, glyphosate-monoisopropylamine salt, and Roundup Gran) and two types of microplastics (polyethylene (PE) microbeads and polyethylene terephthalate/polyamide (PET/PA) fibers), on Daphnia magna. Glyphosate-monoisopropylamine salt caused the highest mortality after 1 week exposure (23.3%), whereas glyphosate acid the lowest (12.5%), when tested in the absence of microplastics. These results were inverted, however, when the individuals were exposed in combination with the PE microbeads (glyphosate acid: 53.3% and glyphosate-monoisopropylamine salt: 18.3%) or the PET/PA fibers (glyphosate acid: 30.0% and glyphosate-monoisopropylamine salt: 8.3%). The mortality in the Roundup Gran formulation also increased when combined with the two microplastics, though the effect was less pronounced. In all experiments, the effect of the treatments and time was significant, though there was no significant interaction between them. In most treatments, negative effects were not observed after 48 h or later. The change in toxicity of the glyphosate formulations caused by microplastics can be linked to the different sorption properties of the glyphosate-based chemicals formulations. The outcome of this study highlights that beside the potential direct negative effects of microplastics, they can modify the toxicity of pollutants, such as herbicides.
塑料污染是一个环境问题，甚至已经蔓延到最偏远的水生和陆地栖息地，尤其是微塑料对生物构成了不确定的威胁。微塑料可能会产生直接的负面影响，但它们也可能改变污染物的毒性和生物利用度。在这里，我们在超过 1 周的时间里测试了三种不同的草甘膦化学配方（草甘膦酸、草甘膦单异丙胺盐和农达颗粒剂）和两种类型的微塑料（聚乙烯（PE）微珠和聚对苯二甲酸乙二醇酯/聚酰胺（PET/PA）纤维）对大型溞（Daphnia magna）的联合影响。在没有微塑料的情况下，草甘膦单异丙胺盐在暴露 1 周后导致最高死亡率（23.3%），而草甘膦酸的死亡率最低（12.5%）。然而，当个体暴露于与 PE 微珠（草甘膦酸：53.3%和草甘膦单异丙胺盐：18.3%）或 PET/PA 纤维（草甘膦酸：30.0%和草甘膦单异丙胺盐：8.3%）结合时，结果则相反。草甘膦单异丙胺盐和草甘膦酸与两种微塑料组合时，农达颗粒剂的死亡率也有所增加，尽管效果不太明显。在所有实验中，处理和时间的影响均显著，但它们之间没有显著的相互作用。在大多数处理中，48 小时或更长时间后未观察到毒性的变化。微塑料引起的草甘膦制剂毒性变化可归因于基于草甘膦的化学制剂的不同吸附特性。这项研究的结果强调了，除了微塑料可能产生的直接负面影响外，它们还可以改变污染物的毒性，如除草剂。
