The rapid development of nanotechnology and the increased use of nanomaterials in products used in everyday life have raised the question of the potential release of nanoparticles into the aquatic environment. Their fate and effects in natural ecosystems are not currently well understood but harmful effects of nanoparticles have been demonstrated at low concentrations on some freshwater and marine species. Cerium dioxide nanoparticles (CeO₂ NPs) are produced in large quantities and used in products in many different fields, such as automotives or optics. Because of their widespread use in daily products, CeO₂ NPs are included in the OECD priority list of manufactured nanomaterials for human and environmental assessment. Indeed some studies have been conducted to assay various enzymatic biomarkers, which showed the CeO₂ NPs potential to modify anti-oxidative defenses and cellular membrane stability. Nevertheless, only a few studies were performed on their genotoxic potential. The aim of this work was to evaluate the genotoxic and physiological effects of CeO₂ NPs on a widespread freshwater bivalve Corbicula fluminea by using comet assay and a multi-enzymatic biomarker approach. Exposure to two CeO₂ NP concentrations during a short term experiment (6 days) was set up. The first one (10 μg/L) was chosen in order to work with low but measurable concentrations whereas the second one was ten times higher (100 μg CeO₂ NPs/L). DNA damage was significantly more pronounced compared with control for both concentrations tested as early as two days of exposure and seemed to increase with time. Some enzymatic biomarkers of anti-oxidative defenses (total antioxidant capacity, catalase activity), anti-toxic mechanisms (glutathione-S-transferase activity, caspase-3 activity) or metabolism (lactate dehydrogenase activity) tended to increase after 6 days of exposure but only the induction of caspase pathway and DNA damages appeared significant for exposed organisms. In this study, time and concentration effects of CeO₂ NPs were highlighted by coupling genotoxic and cellular biomarker assessments.

纳米技术的飞速发展和在日常生活中使用的产品中纳米材料的使用增加，提出了将纳米颗粒潜在释放到水生环境中的问题。目前尚不清楚它们在自然生态系统中的命运和影响，但已证明低浓度的纳米颗粒对某些淡水和海洋物种的有害影响。二氧化铈纳米颗粒（CeO ₂ NPs）大量生产，并用于许多不同领域的产品中，例如汽车或光学。由于其在日常产品中的广泛使用，CeO ₂NP被列入经合组织用于人类和环境评估的人造纳米材料的优先清单。实际上，已经进行了一些研究来测定各种酶促生物标记，这些研究表明CeO ₂ NP具有修饰抗氧化防御和细胞膜稳定性的潜力。尽管如此，仅对其遗传毒性潜力进行了少量研究。这项工作的目的是通过彗星试验和多酶生物标记方法，评估CeO ₂ NPs对广泛的淡水双壳类长鞭毛藻的遗传毒性和生理作用。暴露于两个CeO ₂建立了短期实验（6天）中的NP浓度。选择第一个（10μg/ L）是为了在低但可测量的浓度下工作，而第二个要高十倍（100μgCeO ₂ NPs / L）。早在暴露两天时测试的两种浓度的DNA损伤都比对照组明显更为明显，并且似乎随时间增加。暴露后6天，一些抗氧化防御作用（总抗氧化能力，过氧化氢酶活性），抗毒性机制（谷胱甘肽-S-转移酶活性，caspase-3活性）或新陈代谢（乳酸脱氢酶活性）的酶生物标记物趋于增加，但只有半胱天冬酶途径的诱导和DNA损伤对于暴露的生物才显得很重要。在这项研究中，时间和浓度对CeO的影响通过遗传毒性和细胞生物标志物评估相结合，突出显示了_2个NP。