Institute of Science and Technology, São Paulo State University, UNESP, 3 de Março Avenue 511, Alto da Boa Vista, Sorocaba 18087-180, Brazil; Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, USP, Prof. Lineu Prestes Avenue 748, São Paulo 05508-000, Brazil.
Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, USP, Prof. Lineu Prestes Avenue 748, São Paulo 05508-000, Brazil; Department of Ecology, Institute of Biosciences, University of São Paulo, USP, Matão Street 321, São Paulo 05508-090, Brazil.
Aquat Toxicol. 2023 May;258:106516. doi: 10.1016/j.aquatox.2023.106516. Epub 2023 Mar 30.
Microplastics are widespread pollutants in the environment and are considered a global pollution problem. Microplastics mostly originate from larger plastics and due to environmental conditions are undergoing constant fragmentation processes. It is important to understand the fragmentation pathways, since they play a key role in the fate of the particles, and also directly influence toxicity. Amphipods are potential inducers of plastic debris fragmentation. Here, Hyalella azteca was exposed to different concentrations (540, 2700, 5400 items/L) of 24.5 µm polystyrene microplastics (PS-MP) for 7 days. After exposure, oxidative stress, particle size reduction, and mortality were checked. No significant mortality was seen in any of the treatments, although changes were recorded in all enzymatic biomarkers analyzed. It was observed that throughout the ingestion and egestion of PS-MP by H. azteca, particles underwent intense fragmentation, presenting a final size up to 25.3% smaller than the initial size. The fragmentation over time (24, 72, 120, 168 h) was verified and the results showed a constant reduction in average particle size indicating that H. azteca are able to induce PS-MP fragmentation. This process may facilitate bioaccumulation and trophic particle transfer.
微塑料是环境中广泛存在的污染物，被认为是一个全球性的污染问题。微塑料主要来源于较大的塑料，由于环境条件的影响，它们不断经历碎片化过程。了解碎片化途径很重要，因为它们在颗粒的命运中起着关键作用，并且直接影响毒性。片脚类动物是塑料碎片碎片化的潜在诱导物。在这里，亚得里亚海螯虾（Hyalella azteca）暴露于不同浓度（540、2700、5400 个/L）的 24.5µm 聚苯乙烯微塑料（PS-MP）中 7 天。暴露后，检查了氧化应激、粒径减小和死亡率。在任何处理中都没有观察到明显的死亡率，尽管所有分析的酶生物标志物都发生了变化。观察到在 H. azteca 摄入和排泄 PS-MP 的过程中，颗粒经历了强烈的碎片化，最终粒径比初始粒径小 25.3%。验证了随时间（24、72、120、168 小时）的碎片化，结果表明平均粒径持续减小，表明 H. azteca 能够诱导 PS-MP 碎片化。这个过程可能促进生物累积和营养级颗粒转移。
