Occurrence, fate, and toxicity of benzotriazole ultraviolet stabilizers in fish

Owing to their strong absorption of ultraviolet light, benzotriazole ultraviolet stabilizers (BUVSs) are extensively utilized in various personal care products and industrial applications. However, BUVSs can easily enter aquatic environments and interact with fish through multiple pathways, posing health risks to ecosystems and humans. Thus, a comprehensive summary of the interactions between BUVSs and fish is of vital significance. BUVSs have been ubiquitously detected in global wild fish, and their bioaccumulation capacities show species-specific and tissue-specific patterns. Notably, the highest detected concentration of BUVSs in wild fish is 2360 ng/g lipid weight, with a bioaccumulation factor value of 194985. However, the potential human health risks associated with fish consumption cannot be accurately determined due to the lack of established tolerable or acceptable daily intakes. This review summarizes laboratory studies elucidating the uptake, distribution, and metabolic processes of BUVSs in fish. Upon absorption by fish, BUVSs are distributed into various organs and tissues, with liver tissue consistently showing a high accumulation capacity. Subsequently, BUVSs can be metabolized into novel transformation products through multiple processes, such as hydration, reduction, oxidation, and dehydration. The various adverse effects of BUVSs on fish are also summarized herein. Exposure to BUVSs can lead to developmental toxicity, neurotoxicity, immunotoxicity, and reproductive toxicity. Finally, this review proposes that future studies should evaluate the toxic mechanisms of BUVSs in wild fish, with particular emphasis on the effects of long-term exposure to environmentally relevant concentrations of BUVSs and the potential human health risks posed by contaminated fish consumption.