Increasing scientific attention on the presence of micro- and nanoplastics (MNPs) in the environments and their potential toxic effects on humans and the ecosystems is evident. Accordingly, the number of publications on this topic has increased substantially from only 5 in 2010 to more than 850 in 2019. Thus, this critical review aimed at providing state-of-the-art information on the existing methods for characterization and detection of MNPs in various matrices, as well as the reported toxic effects of MNPs in both in vivo and in vitro systems, anticipating challenges and providing future needs to improve the current scientific knowledge. We performed a systematic search of recent literature on available methodologies for the characterization/detection of MNPs in different samples, and the summary of such protocols is provided. Also, the existing procedures for in vitro and in vivo toxicity evaluation of MNPs were critically described. The results of our search revealed that quite a great deal of effort had been made to detect, characterize, and quantify the fate and effect of MNPs. However, we are still far from a complete understanding of behaviors of MNPs in the environments and biological systems. Thus, there is a need to advance the existing protocols to improve data accuracy. Besides, more studies that focus on uptake kinetics, accumulation, and biodistribution of MNPs in biological systems are required.

中文翻译：

---

关于当前问题，局限性以及对微塑料和纳米塑料研究的未来研究需求的批判性观点：从检测到毒理学评估。

显然，人们越来越关注环境中存在的微塑料和纳米塑料（MNP）及其对人类和生态系统的潜在毒性作用。因此，有关该主题的出版物数量已从2010年的仅5种增加到2019年的850多种。因此，这项重要的审查旨在提供有关表征和检测MNP的现有方法的最新信息。 MNP在体内和体外系统中的毒性作用，以及预期的挑战并为提高当前的科学知识提供了未来需求。我们对可用于表征/检测不同样品中MNP的方法的最新文献进行了系统搜索，并提供了此类协议的摘要。还，严格描述了MNPs体外和体内毒性评估的现有程序。我们的搜索结果表明，在检测，表征和量化MNP的命运和作用方面已经付出了很大的努力。但是，我们对MNP在环境和生物系统中的行为还没有一个完整的了解。因此，需要改进现有协议以提高数据准确性。此外，还需要开展更多研究，以研究生物系统中MNP的吸收动力学，积累和生物分布。我们对MNP在环境和生物系统中的行为还没有一个完整的了解。因此，需要改进现有协议以提高数据准确性。此外，还需要开展更多研究，以研究生物系统中MNP的吸收动力学，积累和生物分布。我们对MNP在环境和生物系统中的行为还没有一个完整的了解。因此，需要改进现有协议以提高数据准确性。此外，还需要开展更多研究，以研究生物系统中MNP的吸收动力学，积累和生物分布。