Laboratory of Biochemistry and Environmental Toxicology, Higher Institute of Agronomy, University of Sousse, Tunisia; University of Monastir, Higher Institute of Biotechnology of Monastir, Monastir, Tunisia.
University of Messina, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, 98166 Messina, Italy.
Sci Total Environ. 2022 Sep 10;838(Pt 1):155872. doi: 10.1016/j.scitotenv.2022.155872. Epub 2022 May 13.
Coastal areas are worldwide subject to large inputs of anthropogenic wastes that are discharged directly into inshore waters, where they will be weathered into small microplastics (MPs) of up to a size <20 μm. This study provides information about the presence of small environmental MPs (≤3 μm) in the liver of adult benthopelagic fish Serranus scriba (Linnaeus 1758), caught from three coastal regions in Tunisia distinguished by different patterns of human activity. Polymer composition in fish liver was identified using Raman microspectroscopy. Results revealed differences in the abundance, size distribution and presence of plastic additives over the investigated sites. Polyethylene-vinyl acetate (PEVA: 34% particles/g of tissue), high density polyethylene (HDPE: 24.4%) and the two smaller size classes, i.e. 3-1.2 μm and 1.2-0.45 μm, were the most abundant MPs types and size distribution found, respectively, in Bizerte channel (BC) site (Bizerte city, Tunisia). Moreover, at hepatic level data showed a significant site-dependent cytotoxicity expressed by changes in malondialdehyde (MDA) content, presence of reactive oxygen species (ROS) expressed by altered level of catalase (CAT) and glutathione-S-transferase (GST) activities and in the content of metallothioneins (MTs), as well as genotoxicity by changes in the amount of micronucleus (MN), and neurotoxicity by altered activity of acetylcholinesterase (AChE). A innovative metabolomics analysis was also performed to further investigate the distinct patterns of key metabolite changes in the liver of Serranus scriba. A total of 36 metabolites were significantly affected, mainly involved in energy, amino acid and osmolyte metabolism. These findings emphasised for the first time a close relationship between the source, abundance and size ranges of environmental MPs ≤ 3 μm and their hepatotoxicity in wild organisms.
沿海地区是全球范围内人为废弃物的大量输入地，这些废弃物直接排放到近岸水域，在那里它们会风化形成小尺寸的微塑料（MPs），最大粒径可达 20μm 以下。本研究提供了关于小尺寸环境 MPs（≤3μm）在成年底栖洄游鱼类丝鲹（Linnaeus 1758）肝脏中的存在情况的信息，这些鱼是从突尼斯三个沿海地区捕获的，这三个地区的人类活动模式不同。使用拉曼微光谱法鉴定了鱼肝脏中的聚合物组成。结果表明，在所研究的地点之间，塑料添加剂的丰度、大小分布和存在存在差异。聚乙烯-醋酸乙烯酯（PEVA：34%颗粒/组织）、高密度聚乙烯（HDPE：24.4%）和两个较小的尺寸类别，即 3-1.2μm 和 1.2-0.45μm，是最丰富的 MPs 类型和大小分布，分别在比塞大海峡（BC）地点（突尼斯比塞大市）发现。此外，在肝水平上的数据显示了一种显著的、依赖于地点的细胞毒性，表现为丙二醛（MDA）含量的变化、过氧化氢酶（CAT）和谷胱甘肽-S-转移酶（GST）活性改变所表达的活性氧（ROS）的存在以及金属硫蛋白（MTs）的含量，以及微核（MN）数量的变化所导致的遗传毒性，以及乙酰胆碱酯酶（AChE）活性改变所导致的神经毒性。还进行了创新性的代谢组学分析，以进一步研究丝鲹肝脏中关键代谢物变化的不同模式。共有 36 种代谢物受到显著影响，主要涉及能量、氨基酸和渗透物代谢。这些发现首次强调了环境 MPs（≤3μm）的来源、丰度和尺寸范围与其在野生生物中的肝毒性之间的密切关系。
