摘要:
微塑料对陆地生态系统的影响关注度日益上升，评估无脊椎动物在这些生态系统中对微塑料的影响至关重要。通常，微塑料（Microplastics，MPs）通过处置不当的塑料废品或在农业土壤上施用经处理的生物固体和/或废水进入环境。本研究旨在探究三种陆生等足类动物——球鼠妇（Porcellio scaber）、光滑鼠妇（Porcellio laevis）和多霜蜡鼠妇（Porcellionides pruinosus）——在接触塑料碎片24 h至14 d期间是否会摄入塑料碎片并生成MPs，以及这种摄入和生成是否会对它们的健康产生有害作用。试验在特制的容器中进行，这些容器被设计以确保等足类动物能够接触到聚乙烯塑料泡沫碎片。等足类动物被暴露在塑料碎片中，这些碎片是(1)原始的，或者是(2)在土壤和水溶液中风化后的，然后再被放入测试容器中。当暴露在风化后聚乙烯中时，所有三个物种都通过摄食大塑性碎片产生MPs(包括所有持续时间的最小-最大尺寸值: P. laevis = 114-1673 µm, P. scaber = 99-1635 µm, P. pruinosus = 85-1113 µm)，而未观察到对其健康的有害作用。在较短的暴露时间内，本研究中的等足类物种产生的MPs数量在测试容器之间存在较大差异（暴露14 d的最小-最大MPs: P. laevis = 25-420, P. scaber = 50-583, P. pruinosus = 48-311）。然而，随着暴露时间的增加，MPs的产生呈现出明显的上升趋势，这表明等足类动物会持续消耗风化后的塑料碎片。此外，所产生的MPs的尺寸也存在显著差异，较小的等足类物种产生的MP碎片尺寸均值较小。本研究的结果证实，一些等足类动物可以促进MPs的产生，这是土壤生态系统暴露MPs的另一潜在途径。
原文链接：https://doi.org/10.1002/etc.5812
Abstract:
With concern growing regarding the impact of microplastics (MPs) on terrestrial ecosystems, it is important to assess the role invertebrates may play in the fate of MPs within these ecosystems. Commonly, MPs enter these environments through improperly discarded waste or the application of treated biosolids and/or wastewater on agricultural soils. The present study investigated whether three species of terrestrial isopod (Porcellio scaber, Porcellio laevis, and Porcellionides pruinosus) ingest plastic debris and generate MPs during exposures varying from 24 h to 14 days and whether this may have an adverse effect on their health. Test vessels were designed to expose isopods to plastic fragments in the form of polyethylene plastic foam. Isopods were exposed to plastic that was either (1) pristine, or (2) weathered in a soil and water solution prior to incorporation in test vessels. When exposed to weathered polyethylene, all three species generated MPs (minimum–maximum size values for all durations inclusive: P. laevis = 114–1673 µm, P. scaber = 99–1635 µm, P. pruinosus = 85–1113 µm) through the consumption of macroplastic fragments with no observed impact on their health. In the shorter-duration exposures, the number of MPs generated by the isopod species in the present study was highly variable between experimental vessels (minimum–maximum generated MPs for 14-day exposure: P. laevis = 25–420, P. scaber = 50–583, P. pruinosus = 48–311). However, as the exposure durations increased, there was a clear trend of increasing MP generation, indicating that the isopods continued to consume the plastic fragments as long as the surface was weathered. A significant difference in the size of generated MPs was observed as well, with smaller isopod species generating smaller MP fragments on average. The results of the present study confirm that certain species of isopod can contribute to the generation of MPs, which constitutes an additional pathway of MP exposure to soil ecosystems.
View more in https://doi.org/10.1002/etc.5812
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