Leite Carla, Russo Tania, Polese Gianluca, Soares Amadeu M V M, Pretti Carlo, Pereira Eduarda, Freitas Rosa
Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro, Portugal.
Department of Biology, University of Naples Federico II, 80126 Napoli, Italy.
J Xenobiot. 2024 Dec 18;14(4):2015-2038. doi: 10.3390/jox14040108.
The growing use of products containing rare earth elements (REEs) may lead to higher environmental emissions of these elements, which can potentially enter aquatic systems. Praseodymium (Pr) and europium (Eu) are widely used REEs with various applications. However, their ecotoxicological impacts remain largely unexplored, with poorly understood risks to wildlife. Moreover, organisms also face environmental stressors like salinity fluctuations, and the nature of the interaction between salinity variations and contaminants is not yet clear. Therefore, this study aimed to evaluate the influence of salinity shifts on the impacts of Pr and Eu on adult mussels and the sperm of the species after 28 days and 30 min of exposure, respectively. To do so, biochemical and histopathological alterations were evaluated in adults, while biochemical and physiological changes were analysed in sperm. Additionally, the Integrated Biological Index (IBR) was calculated to understand the overall impact of each treatment. The results showed that adult mussels were most affected when exposed to the combination of high salinity and each element, which altered the behaviour of defence mechanisms causing redox imbalance and cellular damage. On the other hand, sperm demonstrated sensitivity to specific REE-salinity combinations, particularly Pr at lower salinity and Eu at higher salinity. These specific treatments elicited changes in sperm motility and velocity: Pr 20 led to a higher production of O and a decrease in velocity, while Eu 40 resulted in reduced motility and an increase in irregular movement. At both lower and higher salinity levels, exposure to Eu caused similar sensitivities in adults and sperm, reflected by comparable IBR scores. In contrast, Pr exposure induced greater alterations in sperm than in adult mussels at lower salinity, whereas the reverse was observed at higher salinity. These findings suggest that reproductive success and population dynamics could be modulated by interactions between salinity levels and REE pollution, highlighting the need for further investigation into how REEs and environmental factors interact. This study offers valuable insights to inform policymakers about the potential risks of REE contamination, emphasising the importance of implementing environmental regulations and developing strategies to mitigate the impact of these pollutants.
含稀土元素（REEs）产品的使用日益增加，可能导致这些元素向环境中的排放量增加，这些元素有可能进入水生系统。镨（Pr）和铕（Eu）是用途广泛的稀土元素，有各种应用。然而，它们的生态毒理学影响在很大程度上仍未得到探索，对野生动物的风险了解甚少。此外，生物还面临盐度波动等环境压力源，盐度变化与污染物之间相互作用的性质尚不清楚。因此，本研究旨在评估盐度变化对镨和铕分别暴露28天和30分钟后对成年贻贝和该物种精子的影响。为此，对成年贻贝进行了生化和组织病理学改变评估，同时对精子进行了生化和生理变化分析。此外，计算了综合生物学指数（IBR）以了解每种处理的总体影响。结果表明，成年贻贝在暴露于高盐度与每种元素的组合时受到的影响最大，这改变了防御机制的行为，导致氧化还原失衡和细胞损伤。另一方面，精子对特定的稀土元素 - 盐度组合表现出敏感性，特别是在低盐度下的镨和高盐度下的铕。这些特定处理引起了精子活力和速度的变化：Pr 20导致O产量增加和速度降低，而Eu 40导致活力降低和不规则运动增加。在低盐度和高盐度水平下，暴露于铕都会使成年贻贝和精子产生类似的敏感性，这在可比的IBR分数中得到体现。相比之下，在低盐度下，镨暴露对精子的影响比对成年贻贝的影响更大，而在高盐度下则观察到相反的情况。这些发现表明，繁殖成功率和种群动态可能受到盐度水平与稀土元素污染之间相互作用的调节，突出了进一步研究稀土元素与环境因素如何相互作用的必要性。本研究提供了有价值的见解，以便为政策制定者提供有关稀土元素污染潜在风险的信息，强调实施环境法规和制定战略以减轻这些污染物影响的重要性。
