Nanoplastics in the Environment and the Effects on the Zebrafish

Abstract

Plastic is one of the most used materials in the world, adopted in almost all activities of human life, but due to the high persistence and durability in the environment, it is causing pollution problems. Through different processes, small particles of polymers are emerging and the effects on the health are still unknown. The Danio rerio (zebrafish) is a model organism that serves as a reference for the assessment of the safety of Nanoplastics (NPs) and Microplastics (MPs). The effects on development, central nervous system, behavior and genetic regulation, are some of the evidences that are already available thanks to the studies developed in recent years. The potential exacerbation of toxicity by co-exposure of the NPs and MP with other contaminants has been demonstrated through several studies. Furthermore, the challenge that must be overcome is the lack of uniformity in the analytical methodology that helps to generate conclusive and parallel results.

Mercury Accumulation and Elimination in Different Tissues of Zebrafish (Danio rerio) Exposed to a Mercury-Supplemented Diet

“…Mercury tends to be accumulated in detoxification organs such as the liver and kidney [21], although fish muscle is the most analyzed tissue to evaluate Hg accumulations as it seems to function as a Hg reservoir in order to protect other organs [22], in addition to being the main fish tissue consumed by humans [23]. Muscle has been reported to enhance long-term bioaccumulation due to the increased capacity to accumulate Hg when compared to the other organs.…”

“…Therefore, the presence of Hg in seafood continues to pose a public health concern, with fish consumption as the major route for Hg exposure in humans [32,33]. Zebrafish (Danio rerio) have been used as biological model for environmental toxicology research due to the relatively small size of the adult fish and the external fertilization and transparency during development, characteristics that permit a large number of samples and simple laboratory management [21,34]. In the context of the dietary Hg exposure assessment, the use of zebrafish is highly relevant due to Danio rerio homologies to humans [21,34]; they have heart chambers that rhythmically pump oxygen-carrying blood through the body, they have eyes with a retinal structure, a liver, pancreas, kidneys and intestines, backbone, and more than 80% of their genes have human counterparts [35].…”

“…Zebrafish (Danio rerio) have been used as biological model for environmental toxicology research due to the relatively small size of the adult fish and the external fertilization and transparency during development, characteristics that permit a large number of samples and simple laboratory management [21,34]. In the context of the dietary Hg exposure assessment, the use of zebrafish is highly relevant due to Danio rerio homologies to humans [21,34]; they have heart chambers that rhythmically pump oxygen-carrying blood through the body, they have eyes with a retinal structure, a liver, pancreas, kidneys and intestines, backbone, and more than 80% of their genes have human counterparts [35]. The Hg accumulation and elimination dynamics in different tissues due to dietary fish exposure could have a toxicological and/or nutritional approach and purpose, emphasizing differences in physiological functions and among the main organs' role in these processes.…”