Recent advances of microplastics toxicity and fate on zebrafish-a review

Plastics have become an indispensable part of our lives due to their low cost and long lifespan, and their production is increasing. They are broken down into small structures, such as microplastics and nanoplastics, through different pathways. Compared to macro-sized plastics, their penetration and transport rates are significantly higher. They can remain without degradation for many years when released into the environmental habitat. They can be toxic due to the chemical structures added to provide flexibility or resistance to high and low temperatures during plastic production. Therefore, they can become an essential pollutant in the ecosystem. They can cause adverse effects on aquatic organisms by disrupting the balance of various water parameters, causing bioaccumulation in aquatic environments, and threatening the aquatic ecosystem. These small-sized plastics can cause anomalies in the organs of aquatic organisms. Toxicity is observed in the tissues of fish exposed to nano and microplastics in aquatic environments. They can cause developmental, reproductive, and gastrointestinal system disorders, oxidative stress, and toxicity by showing bioaccumulation in the tissues. The effects of these substances on organisms such as high trophic level fish constantly increase. In recent years, zebrafish and embryos have frequently been preferred to evaluate the toxic effects of plastics. This review aims to evaluate the effects of micro and nanoplastics, which pose a risk to ecosystems and organisms due to increasing plastic usage, on zebrafish as a model organism through a series of systems such as reproductive toxicity, neurotoxicity, locomotor activity, cardiotoxicity, hepatotoxicity, oxidative stress, and developmental toxicity.