Review of mechanisms and impacts of nanoplastic toxicity in aquatic organisms and potential impacts on human health.

The harmful environmental impact of plastic waste has justifiably received substantial attention from the scientific community. In contrast, the toxicological effects of nanoplastics (NP) on aquatic organisms, as well as the potential implications for human health, remain largely unexplored and poorly understood. Despite the growing awareness of plastic pollution, the risks associated with the ubiquitous presence of nanoplastics in our food and beverages are not yet fully recognized. NPs, which are smaller than 1 µm, along with a mixture of MPs and plastic fragments, can find their way into water bodies through various sources and may easily be taken up by aquatic organisms. This paper summarizes the existing literature on NPs bioavailability, their accumulation patterns within the tissues of fish, shellfish, and zooplankton, as well as the influence of biological and environmental factors on NPs absorption from water and diet. Study indicated that the NPs pose significant risks to both aquatic ecosystems and human health due to their ability to bioaccumulate in marine organisms and biomagnify through the food web. It highlighted that various aquatic species can ingest NPs, leading to their distribution across different tissues, which may result in toxic effects such as oxidative stress, DNA damage, and inflammation, as well as impacts on growth and reproduction. The identified critical gaps in current research, particularly regarding the long-term effects of low-dose NP exposure and the need for standardized testing methodologies to ensure comparability across studies. Furthermore, the necessity for further research to understand the pathways through which humans may be exposed to NPs, their toxicokinetics, and the potential implications for chronic health issues. Therefore, more studies are required which employ rigorous and uniform methodologies to fully address NPs as an emerging threat within aquatic ecosystems and food chains; accurately assess related risks with human health together with cumulative toxicity perhaps when combined with other pollutants.