Tritiated Water Exposure in Zebrafish (Danio rerio): Effects on the Early‐Life Stages

Abstract

Tritium, a radioactive isotope of hydrogen of natural and anthropogenic origin, is ubiquitously present in the environment. Effluents of nuclear centers of production are significant anthropogenic sources. With the upcoming project of thermonuclear fusion, tritium releases in the environment may increase. It is therefore important to characterize the ecological risk linked to tritium. The effects of tritiated water (HTO) were therefore studied in zebrafish larvae exposed for 10 d to different dose rates, 1.1 × 102, 4.1 × 102, and 3.8 × 103 µGy/h for larvae corresponding, respectively, to a water contamination of 104, 105, and 106 Bq/mL of HTO. Those dose rates were higher than 10 μGy/h, which is the threshold recommended to start monitoring ecosystems where radiological contaminants are present. Mortality, embryo‐larval development, immune toxicity, genotoxicity, neurotoxicity, and alterations of tissues were investigated. The results showed that HTO exposure induced DNA damage and reactive oxygen species production and modulated the expression of genes involved in detoxification processes. Moreover, modifications of the muscular tissues (degradation of myofibrils at 4 d post fertilization and disorganization of mitochondria at later stages) were observed. The results differed with HTO dose rates and with developmental stages. These results will drive future research for the development of new HTO‐sensitive biomarkers and will allow us to progress in the characterization of the modes of action of tritium in fish. Environ Toxicol Chem 2020;39:648–658. © 2019 SETAC

Neurotoxic Anatoxin-a Can Also Exert Immunotoxicity by the Induction of Apoptosis on Carassius auratus Lymphocytes in vitro When Exposed to Environmentally Relevant Concentrations

“…Many studies report that chemical environmental pollutants can induce ROS production in fish cells (Garcia-Gomez et al, 2020). Gagnaire et al (2019) revealed that DNA damage and ROS production were caused by the exposure of tritiated water. Our previous studies also showed the increase of ROS in cells after exposed to nodularin and microcystins (Zhang et al, 2014a).…”

Toxic effects of combined exposure of tritiated water and genistein on the growth and development of zebrafish and its mechanism

“…The up-regulation of a large number of genes in the two biological processes of redox and lipid transport in GO analysis also indicates that the antioxidant system in zebrafish has been disorder. It has been reported that exposure to tritiated water will also increase the level of ROS in zebrafish larvae (Gagnaire et al, 2020). We speculate that in terms of oxidative stress, the combined effects of tritiated water and genistein on zebrafish embryos may be superimposed, which leads to excessively high active oxygen of zebrafish larvae, and the original balanced redox system in the body is disrupted, thus affecting the normal function of cells.…”

Transcriptome Analysis of the Immortal Human Keratinocyte HaCaT Cell Line Damaged by Tritiated Water

“…Some characteristics related to apoptosis and senescence ensued, such as cell cycle arrest, increased γ H2AX and IL-8 contents, as well as an increase in the proportion of positive cells stained with β -galactosidase (SA- β -gal) [ 14 , 24 ]. Second, as ionizing radiation, Tritium caused the radiolysis of water, which promoted the formation of ROS [ 36 ] to attack intracellular biological macromolecules such as DNA, protein and lipids, causing cell damage [ 37 ]. In addition, Li et al treated AHH-1-1 with 3.7 × 10 6 Bq/mL tritiated water, and only 72.1% of the cells survived [ 17 ].…”