Fluorescent carbon dot embedded polystyrene nanoplastic: In vivo toxicity assessment and bioaccumulation study in Daphnia magna

The levels of nano- and microplastic in the aquatic environment rises due to the industrial production of plastic and the degradation of plastic into smaller particles. We have limited knowledge about what happens to nanoplastic specifically in freshwater environments. Acute toxicity study of carbon dot embedded polystyrene nanoplastic (CDPS-NP) was conducted according to OECD-202 guidelines (OECD, 2004) in Daphnia magna . The distribution of CDPS-NPs and its impact on aspects of D. magna’ s life cycle, such as growth, motility and mortality rate and occurrence of malformations was examined. Daphnids were placed in individual containers and exposed to various concentrations of test media over a 48-hr period. Mortality was taken as the endpoint of the test. The exposure of CDPS-NPs led to reduced body size and severe disruptions in reproduction. Its bioaccumulation in body was confirmed using fluorescent microscopy. Exposure to PS-NPs caused an increase in mortality with an increase in concentration. The changes observed were found to be time and concentration dependent. Overall, these data indicated that the acute toxic effects of CDPS-NPs exposure on neonates were more pronounced than in adults.