Effects of in vivo exposure to tritium: a multi-biomarker approach using the fathead minnow, Pimephales promelas

• Published in: Environmental science and pollution research international Vol. 27; no. 4; pp. 3612 - 3623
• Main Authors: Gagnaire, Béatrice, Gosselin, Isabelle, Festarini, Amy, Walsh, Stephanie, Cavalié, Isabelle, Adam-Guillermin, Christelle, Della-Vedova, Claire, Farrow, Francesca, Kim, Sang Bog, Shkarupin, Alexi, Chen, Hui Qun, Beaton, Danielle, Stuart, Marilyne
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2020; Springer Nature B.V; Springer Verlag
• Subjects: Acetylcholinesterase; Amino acids; Animal tissues; Animals; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Background levels; Biomarkers; Biomarkers - metabolism; Brain damage; Contaminants; Cosmic rays; Cyprinidae - physiology; Deoxyribonucleic acid; Depuration; DNA; Dosage; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Environmental Sciences; Exposure; Fatty acids; Fish; Food Contamination, Radioactive; Genotoxicity; Hydrogen storage; Immune response; Laboratories; Metabolism; Multi-Stressors in Freshwater and Transitional Environments: from Legacy Pollutants to Emerging Ones; Natural environment; Nuclear power plants; Nuclear reactors; Organic chemistry; Oxidative stress; Phagocytosis; Proteins; Radiation; Radioisotopes; Reactive oxygen species; Ribonucleic acid; RNA; Tritium; Tritium - toxicity; Waste Water Technology; Water Management; Water Pollutants, Radioactive - toxicity; Water Pollution Control; Fatty acid composition; Neural response; exposure; Genotoxicity; Immune system response; Fathead minnow; Oxidative stress response; Tritium internal dose rate; Fathead minnow, Pimephales promelas; In vivo exposure
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-018-3781-5

Tritium ( 3 H) is a radioactive isotope of hydrogen. In the environment, the most common form of tritium is tritiated water (HTO). However, tritium can also be incorporated into organic molecules, forming organically bound tritium (OBT). The present study characterized the effects of tritium on the health of the fathead minnow, Pimephales promelas . Fish were exposed to a gradient of HTO (activity concentrations of 12,000, 25,000, and 180,000 Bq/L) and OBT using food spiked with tritiated amino acids (OBT only, with an activity concentration of 27,000 Bq/L). A combined exposure condition where fish were placed in 25,000 Bq/L water and received OBT through feed was also studied. Fish were exposed for 60 days, followed by a 60-day depuration period. A battery of health biomarkers were measured in fish tissues at seven time points throughout the 120 days required to complete the exposure and depuration phases. HTO and OBT were also measured in fish tissues at the same time points. Results showed effects of increasing tritium activity concentrations in water after 60 days of exposure. The internal dose rates of tritium, estimated from the tissue free-water tritium (TFWT) and OBT activity concentrations, reached a maximum of 0.65 μGy/h, which is relatively low considering background levels. No effects were observed on survival, fish condition, and metabolic indices (gonado-, hepato-, and spleno-somatic indexes (GSI, HSI, SSI), RNA/DNA and proteins/DNA ratios). Multivariate analyses showed that several biomarkers (DNA damages, micronucleus frequency, brain acetylcholinesterase, lysosomal membrane integrity, phagocytosis activity, and reactive oxygen species production) were exclusively correlated with fish tritium internal dose rate, showing that tritium induced genotoxicity, as well as neural and immune responses. The results were compared with another study on the same fish species where fish were exposed to tritium and other contaminants in natural environments. Together with the field study, the present work provides useful data to identify biomarkers for tritium exposure and better understand modes of action of tritium on the fathead minnow.