The dispersed pollution caused by microplastics (MPs) represents a current and global concern. While the fragmentation of plastic debris into smaller particles occurs in rivers, little MP research is done on freshwater species and is published compared to the marine environment. The Loire River is the longest river in France and is subject to moderate to high anthropic pressure while it represents major societal and economic issues. However, there are not many studies that have been put forward with regards to the effect of environmental MPs (EMPs) on aquatic organisms and no policies have been enacted to monitor the plastic pollution. In this study, freshwater bivalves, Corbicula fluminea, were exposed for 21 days to environmentally relevant concentrations of a mixture of <200 µm MPs generated from plastic litter collected directly along the banks of the Loire River. This mixture was composed of 40% polyethylene (PE), 40% polypropylene (PP), 10% polyethylene terephthalate (PET) and 10% polyvinylchloride (PVC) (mass percentage). Ecotoxicological effects were assessed from the individual to the molecular levels on several endpoints: condition index, filtration efficiency, enzyme activities, lipid peroxidation, energy reserves and gene expression. The ingestion of EMPs caused damages at the biochemical level. Indeed, we reported an increase in catalase activity in gills and digestive mass, a decrease in TBARs in gills, a decrease in acetylcholinesterase activity in the digestive mass, a decrease of glycogen and lipid contents in the whole organisms and a significant induction of the expression of gst, cat, mp, acp genes. The current results suggest therefore that long-term exposure to realistic doses of EMPs causes toxicity towards freshwater benthic biota. The analysis of biomarker activities and the analysis of gene expression are complementary to prevent the effects of a plastic contamination at higher biological levels in aquatic organisms.

微塑料（MP）造成的分散污染是当前全球关注的问题。虽然塑料碎片在河流中破碎成更小的颗粒，但与海洋环境相比，对淡水物种进行的 MP 研究很少，也很少发表。卢瓦尔河是法国最长的河流，承受着中度至高度的人为压力，同时也带来了重大的社会和经济问题。然而，目前关于环境MPs（EMPs）对水生生物影响的研究并不多，也没有制定政策来监测塑料污染。在这项研究中，淡水双壳类河蚬(Corbicula Fluminea ) 暴露于环境相关浓度 <200 µm 的 MP 混合物中 21 天，该混合物是从卢瓦尔河沿岸直接收集的塑料垃圾中产生的。该混合物由40%聚乙烯（PE）、40%聚丙烯（PP）、10%聚对苯二甲酸乙二醇酯（PET）和10%聚氯乙烯（PVC）（质量百分比）组成。从个体到分子水平的几个终点评估了生态毒理学效应：状况指数、过滤效率、酶活性、脂质过氧化、能量储备和基因表达。摄入电磁脉冲会造成生化水平的损害。事实上，我们报道了鳃和消化物中过氧化氢酶活性的增加，鳃中 TBAR 的减少，消化物中乙酰胆碱酯酶活性的降低，整个生物体中糖原和脂质含量的降低以及表达的显着诱导gst 、cat、mp、acp基因。因此，目前的结果表明，长期暴露于实际剂量的电磁脉冲会对淡水底栖生物群造成毒性。生物标志物活性分析和基因表达分析相辅相成，以防止塑料污染对水生生物中较高生物水平的影响。