MARE - Marine and Environmental Sciences Centre, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516, Caparica, Portugal.
MARE - Marine and Environmental Sciences Centre, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516, Caparica, Portugal; UCIBIO, REQUIMTE - Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal.
Environ Pollut. 2019 Feb;245:600-606. doi: 10.1016/j.envpol.2018.11.038. Epub 2018 Nov 15.
Plastic debris has been recognized as a growing threat to marine biota due to its widespread distribution and possible interactions with marine species. Concerns over the effects of plastic polymers in marine ecosystems is reflected in the high number of toxicological studies, regarding microplastics (<5 mm) and marine fauna. Although several studies reported that organisms ingest and subsequently eliminate microplastics (MP), the potential effects at organ and tissue level remain unclear, especially considering exposure to different microplastic sizes and concentrations. The present study aimed at investigating potential pathophysiological effects of the ingestion of MP by marine filter-feeders. For the purpose, Mediterranean mussel (Mytilus galloprovincialis) was exposed to spherical polystyrene MP (2 and 10 μm Ø) over short- and medium-term exposure periods, under single and combined concentrations that represent high, yet realistic doses (10 and 1000 MP mL). Overall, results suggest rapid MP' clearance from water column by filtering, regardless of MP size. Ingestion occurred, identified by MP in the lumen of the gut (mostly in midgut region), followed by excretion through faeces. However, no MP were found in gills or digestive gland diverticula. Biochemical indicators for oxidative stress were generally irresponsive regardless of organ and time of exposure. Small foci of haemocytic infiltration in gastric epithelia were found, albeit not clearly related to MP ingestion. Globally, no evident histopathological damage was recorded in whole-body sections of exposed animals. The present findings highlight the adaptative ability of filter-feeding bivalves to cope with filtration of suspended MP, resulting in rapid elimination and reduced internal damage following ingestion of spherical MP. Nevertheless, the fact that the animals are able to translocate MP to the gut reveals that filter feeding organisms may indeed became a target of concern for fragmented materials with smaller, mixed sizes and sharper edges.
塑料碎片已被公认为对海洋生物群构成日益严重威胁的因素，这是因为其广泛分布并可能与海洋物种相互作用。人们对塑料聚合物在海洋生态系统中产生的影响感到担忧，这反映在大量关于微塑料（<5mm）和海洋动物的毒理学研究中。尽管有几项研究报告称，生物体摄入并随后排出微塑料（MP），但在器官和组织水平上的潜在影响仍不清楚，特别是考虑到不同微塑料尺寸和浓度的暴露。本研究旨在研究海洋滤食者摄入 MP 可能产生的潜在病理生理影响。为此，研究人员采用地中海贻贝（Mytilus galloprovincialis）作为研究对象，使其在短期和中期暴露于不同浓度的球形聚苯乙烯 MP（2 和 10μmØ）中，这些浓度代表了高但现实的剂量（10 和 1000 MP mL）。总的来说，结果表明，无论 MP 大小如何，贻贝都能通过过滤迅速将 MP 从水柱中清除。摄入的 MP 可在肠道腔中发现（主要在中肠区域），随后通过粪便排出。然而，在鳃或消化腺憩室中没有发现 MP。无论器官和暴露时间如何，氧化应激的生化指标通常都没有反应。在胃上皮中发现了小的含铁血黄素细胞浸润灶，但与 MP 摄入无关。在暴露动物的全身切片中，未记录到明显的组织病理学损伤。本研究结果强调了滤食性双壳类动物适应过滤悬浮 MP 的能力，使其在摄入球形 MP 后能够迅速消除并减少内部损伤。然而，动物能够将 MP 转移到肠道的事实表明，滤食性生物可能确实成为了关注焦点，因为这些生物可能成为更小、混合尺寸和更锋利边缘的碎片材料的目标。
