Jahan Israt, Chowdhury Gourab, Rafi Saba, Ashab Md Atique, Sarker Mukta, Chakraborty Ananya, Couetard Nicolas, Kabir Muhammad Anamul, Hossain Mohammad Amzad, Iqbal Mohammed Mahbub
Laboratory of Aquatic Biodiversity and Ecophysiology, Department of Fish Biology and Genetics, Sylhet Agricultural University, Sylhet, 3100, Bangladesh.
Research Centre for Experimental Marine Biology and Biotechnology, Plentzia Marine Station, University of the Basque Country (PiE-UPV/EHU), 48620, Plentzia, Bizkaia, Spain.
Environ Pollut. 2024 Mar 15;345:123548. doi: 10.1016/j.envpol.2024.123548. Epub 2024 Feb 12.
Microplastics (MPs) have been recognized as emerging aquatic pollutants receiving major concern due to their detrimental effects on aquatic life. Nile Tilapia, Oreochromis niloticus is a model species considered in toxicological studies to address the effects of pollutants in freshwater animals. However, comprehensive knowledge comparing the impacts on fish across various MPs polymers is scarce. Therefore, the overarching aim of the current study was to examine the bioconcentration of MPs polymers: polyvinylchloride (PVC), polypropylene (PP), and polyethylene terephthalate (PET), and their toxic effects on growth, and behavioral responses, hematology, and histology of gills, liver, and intestine in O. niloticus. Fishes were subjected to a 21-day dietary exposure to MPs by assigning them into six treatment groups: T (4% of PVC), T (4% of PP), T (4% of PET), T (8% of PVC), T (8% of PP), T (8% of PET), and control (0% of MPs), to assess the effects on fish across the polymers and dosage. Results showed several abnormalities in anatomical and behavioral parameters, lower growth, and high mortality in MPs-exposed fish, indicating a dose-dependent relationship. The elevated dosage of polymers raised the bioavailability of PVC, PP, and PET in gills and gut tissues. Noteworthy erythrocyte degeneration referred to cytotoxicity and stress imposed by MPs, whereas the alterations in hematological parameters were possibly due to blood cell damage, also indicating mechanisms of defense against MPs toxicity. Histopathological changes in the gills, liver, and intestine confirmed the degree of toxicity and associated dysfunctions in fish. A higher sensitivity of O. niloticus to PET-MPs compared to other polymers is likely due to its chemical properties and species-specific morphological and physiological characteristics. Overall, the present study reveals valuable insights into the emerging threat of MPs toxicity in freshwater species, which could be supportive of future toxicological research.
微塑料（MPs）已被公认为是新出现的水生污染物，因其对水生生物的有害影响而受到主要关注。尼罗罗非鱼（Oreochromis niloticus）是毒理学研究中用于探讨淡水动物污染物影响的模式物种。然而，比较不同微塑料聚合物对鱼类影响的全面知识却很匮乏。因此，本研究的总体目标是研究微塑料聚合物：聚氯乙烯（PVC）、聚丙烯（PP）和聚对苯二甲酸乙二酯（PET）的生物富集情况，以及它们对尼罗罗非鱼生长、行为反应、血液学以及鳃、肝脏和肠道组织学的毒性作用。通过将鱼分为六个处理组，使其接受为期21天的微塑料饮食暴露：T1（4%的PVC）、T2（4%的PP）、T3（4%的PET）、T4（8%的PVC）、T5（8%的PP）、T6（8%的PET），以及对照组（0%的微塑料），以评估不同聚合物和剂量对鱼的影响。结果显示，暴露于微塑料的鱼在解剖学和行为参数上出现了一些异常、生长减缓且死亡率较高，表明存在剂量依赖关系。聚合物剂量的增加提高了PVC、PP和PET在鳃和肠道组织中的生物可利用性。值得注意的是，红细胞变性表明微塑料造成了细胞毒性和应激，而血液学参数的改变可能是由于血细胞损伤，这也表明了对微塑料毒性的防御机制。鳃、肝脏和肠道的组织病理学变化证实了鱼的毒性程度和相关功能障碍。尼罗罗非鱼对PET微塑料的敏感性高于其他聚合物，这可能是由于其化学性质以及物种特异性的形态和生理特征。总体而言，本研究揭示了淡水物种中微塑料毒性这一新兴威胁的宝贵见解，可为未来的毒理学研究提供支持。
