Laboratory of Marine Environmental Science, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan.
Laboratory of Marine Environmental Science, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan; Institute of Environmental Health and Ecological Security, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China.
Ecotoxicol Environ Saf. 2021 Apr 1;212:112007. doi: 10.1016/j.ecoenv.2021.112007. Epub 2021 Feb 1.
Microplastic (MP) pollution and the related impacts on aquatic species have drawn worldwide attention. However, knowledge of the kinetic profiles of MPs in fish remains fragmentary. In this study, we conducted exposure and depuration tests of the following fluorescent-labeled MPs: polyethylene (PE; sphere with 200 or 20 µm diameter) and polystyrene (PS; sphere with 20 or 2 µm diameter) using juvenile Japanese medaka (Oryzias latipes). The distribution and concentration of MPs in medaka were directly determined in-situ after tissue transparency. During the 14-day exposure, MPs was mainly detected in the gastrointestinal tract, while some MPs at the size of ≤ 20 µm were located in the area of the gills and head. The bioconcentration factor (BCF; L/kg) for MPs in medaka was estimated as 74.4 (200 µm PE), 25.7 (20 µm PE), 16.8 (20 µm PS), and 139.9 (2 µm PS). Within the first five days of depuration, MPs were exponentially eliminated from the fish body, but 2 µm PS-MPs could be still detected in the gastrointestinal tract at the end of the 10-day depuration phase. Our results suggest that MPs 2 µm in diameter may pose ecological risks to aquatic species due to their relatively higher BCF and the potential for long-term persistence in the body.
微塑料 (MP) 污染及其对水生生物的相关影响引起了全球关注。然而，鱼类中 MPs 的动力学特征的知识仍然很零散。在这项研究中，我们使用幼年的日本青鳉（Oryzias latipes）进行了以下荧光标记的 MPs 的暴露和净化测试：聚乙烯（PE；直径为 200 或 20 µm 的球体）和聚苯乙烯（PS；直径为 20 或 2 µm 的球体）。在组织透明后，直接在原位确定 MPs 在青鳉中的分布和浓度。在 14 天的暴露期间，MPs 主要在胃肠道中被检测到，而一些尺寸≤20 µm 的 MPs 则位于鳃和头部区域。青鳉体内 MPs 的生物浓缩系数（BCF；L/kg）估计为 74.4（200 µm PE）、25.7（20 µm PE）、16.8（20 µm PS）和 139.9（2 µm PS）。在净化的前五天，MPs 从鱼体中呈指数消除，但在 10 天的净化阶段结束时，仍可在胃肠道中检测到 2 µm PS-MPs。我们的研究结果表明，直径为 2 µm 的 MPs 由于其相对较高的 BCF 和在体内长期存在的潜力，可能对水生生物构成生态风险。
