The adverse effects of nanosilver on fish gills: A critical review on ecotoxicity and underlying mechanism.

The environmental safety and health impacts of nanosilver have attracted much attention due to their continuous detection in water. Although the effects of nanosilver on aquatic organisms have been reported, the ecotoxicity and underlying mechanism of nanosilver in aquatic organisms are not fully understood. Fish gills are the primary target organs of pollutant exposure in aquatic environments, and is important to clarify the impact of nanosilver on aquatic organisms by systematically and comprehensively revealing the effect of nanosilver on fish gills. Here, we review the ecotoxicity and potential mechanisms of nanosilver on fish gills. Studies have shown the most commonly used and toxic nanosilver for studying the effects of nanosilver on fish gills is 5-30 nm. Nanosilver mainly affects various physiological functions of fish gills, such as respiration, ion, and osmotic pressure regulation, by disrupting the structure and components of tissues or cells (e.g., cell membranes and mitochondria), as well as interfering with tissue lipid, amino acid, and carbohydrate metabolism. The main mechanisms of toxicity induced by nanosilver in fish gills are gill membrane damage, oxidative stress, and silver ion release. This review provides a scientific basis for the detrimental effects of nanosilver on aquatic ecological environment health and the protection of fish resources.