Polystyrene Nanoplastic Exposure Adversely Affects Survivability of Zebrafish Larvae

The amount of plastics in the environment has continuously increased since the successful synthesis of plastic from fossil fuels. Because of its high durability and stability, plastic has become a necessity in our modern life. However, these plastics break down into small pieces called Nanoparticles (NPs), and are not degraded. Several studies have shown that NPs are toxic to life forms because they could accumulate within living organisms, interfering with their physiological processes. Aquatic lives are more exposed to NP pollution, particularly polystyrene (PS), which is the major ingredient of Styrofoam, as most NP eventually end up in the ocean. However, the effects of NPs on marine vertebrates have not been fully explained yet. I have used zebrafish larvae as a model to assess the effects of NPs on the physiology of aquatic vertebrates. Using fluorescently labeled polystyrene (PS) nanoparticles (PSNPs), I found that sustained exposure of PSNPs to zebrafish larvae had negative effects on the physiology. PSNPs appear to accumulate in diverse regions of the zebrafish larvae, including the gills, eyes, and more importantly, the alimentary canal. Furthermore, sustained exposure to PS nanoparticles led to increased mortality in zebrafish larvae, potentially due to the accumulation in the alimentary canal. Considering that zebrafish share similar physiological characteristics and anatomical features with other commercially important species of fish, my data can be extended to estimate the potential physiological effects of PSNPs on aquatic vertebrates.