Department of Environmental Health Science, Konkuk University , 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea.
Environ Sci Technol. 2017 Nov 7;51(21):12852-12858. doi: 10.1021/acs.est.7b03732. Epub 2017 Oct 25.
In recent years, discarded plastic has become an increasingly prevalent pollutant in aquatic ecosystems. These plastic wastes decompose into microplastics, which pose not only a direct threat to aquatic organisms but also an indirect threat via adsorption of other aquatic pollutants. In this study, we investigated the toxicities of variable and fixed combinations of two types of microplastics [one coated with a carboxyl group (PS-COOH) and the other lacking this functional group (PS)] with the heavy metal nickel (Ni) on Daphnia magna and calculated mixture toxicity using a toxic unit model. We found that toxicity of Ni in combination with either of the two microplastics differed from that of Ni alone. Furthermore, in general, we observed that immobilization of D. magna exposed to Ni combined with PS-COOH was higher than that of D. magna exposed to Ni combined with PS. Collectively, the results of our study indicate that the toxic effects of microplastics and pollutants may vary depending on the specific properties of the pollutant and microplastic functional groups, and further research on the mixture toxicity of various combinations of microplastics and pollutants is warranted.
近年来，废弃塑料已成为水生生态系统中越来越普遍的污染物。这些塑料废物分解成微塑料，不仅直接威胁到水生生物，而且还通过吸附其他水生污染物间接威胁到水生生物。在这项研究中，我们研究了两种类型的微塑料（一种涂有羧基的 PS-COOH 和另一种缺乏此功能基团的 PS）与重金属镍（Ni）的可变和固定组合对大型溞（Daphnia magna）的毒性，并使用毒理学单位模型计算了混合物毒性。我们发现，Ni 与两种微塑料中的任何一种结合的毒性都与单独的 Ni 不同。此外，一般来说，我们观察到 Ni 与 PS-COOH 结合暴露的大型溞的固定化率高于 Ni 与 PS 结合暴露的大型溞。总之，我们的研究结果表明，微塑料和污染物的毒性效应可能取决于污染物和微塑料功能基团的具体性质，有必要对各种微塑料和污染物组合的混合物毒性进行进一步研究。
