ABSTRACT
Presence of microplastics in the marine environment is considered a global threat to several marine animals. Marine plastic debris occurs in seas and oceans globally. In addition, pollutants such as polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCBs) are capable of adsorbing to the plastic surface. Metal pollution is common within harbors and marinas, and originates from multiple sources such as the usage of metal-based antifouling paints, industrial waste, and fuel combustion. In the present study, we investigated the impact of polystyrene MPs (100 nm), silver (Ag) nanoparticle, and their combination on adult zebra fish (Danio rerio). Accumulation, antioxidant defense (ROS, CAT, and Protein), cellular toxicity, and histological analysis were also carried out. The toxic effects of silver and polystyrene combined particle were studied up to 120 hrs. The LC50 value of the combined nanoparticles at 96 h was found to be 48.2 ppm. The behavior of fish was noted at different concentrations (1 ppm, 3 ppm, 9 ppm, and 27 ppm) for every 24 h for 4–5 days. That 308is approx. 96–120 h. Mortality was observed with increasing concentration from 1 to 50 ppm for 96-h exposure. Experiments were conducted for 120 h. Gills and intestine were taken from the treated animals for biochemical analysis and cellular analysis. The oxidative damages caused by Ag-PS were associated with a large number of histological changes. The histological changes reveal a clear stress and apoptosis condition in gill and intestine tissues under a microscope since the polystyrene particles have the ability to bind silver nanoparticle causing toxicity to living organisms. Fourier transform infrared spectroscopy (FT-IR) was performed to investigate the presence of functional groups of silver nanoparticles (Ag-NPs). Silver-polystyrene aggregate (Ag-PS) particle induced great toxicity in zebra fish under higher concentrations. It was found to accumulate in high quantity in the gill and intestines of zebra fish.
