Toxicologia em peixes expostos a micro e nanoplásticos: uma meta-análise em Danio rerio e avaliação em embriões de Rhamdia quelen

Abstract

The ubiquitous contamination from microplastics and nanoplastics represents a growing environmental health challenge, requiring urgent investigations into their impacts on aquatic biota and human health. To verify the toxic effects of micro and nanoplastics on animals, this study was divided into two stages and included a metaanalysis and a bioassay on fish. The first research comprised a meta-analysis using different databases to select studies on oxidative stress caused by micro and nanoplastics in Danio rerio. The data were compiled in a structured table and analyzed in the R software with the metafor package to investigate the relationship between exposure time, concentration, and oxidative stress. The analysis indicated that exposure to micro- and nanoplastics induces oxidative stress in zebrafish larvae and adults, reducing the activity of antioxidant enzymes such as GPx and CAT while increasing the production of ROS. It also induces variable redox imbalance in different zebrafish tissues, with specific effects on the activity of antioxidant enzymes and the production of reactive oxygen species. Furthermore, it adversely affects the activity of antioxidant enzymes and the production of reactive oxygen species in Danio rerio, showing significant variations depending on the type of plastic. The second stage of the research included experimentation to analyze possible toxicological effects in the early stages of the development of Rhamdia quelen exposure to nanoplastics. The study used aminofluorescent polystyrene nanoplastics. Based on environmental data, four treatments were tested, including a control without nanoplastics, with concentrations of 1.0, 5.0, and 10 mg.L-1. Therefore, viable eggs were exposed to these concentrations, monitoring development and survival up to 240 hours postfertilization. Nanoplastics induced significant genetic damage, as evidenced by the comet assay. Furthermore, it was observed that exposure to polystyrene negatively affected the survival of Rhamdia quelen, suggesting potential adverse effects of these materials in the aquatic environment.