Chronic Radium-226 Toxicity to and Oxidative Stress in the Aquatic Invertebrate Chironomus dilutus
Date
2025-01-12
Authors
Lacroix-Durand, Charlotte
Janz, David
Liber, Karsten
Journal Title
Journal ISSN
Volume Title
Publisher
Oxford University Press
ORCID
Type
Article
Degree Level
Abstract
The mining industry, including uranium mining and milling, is of high importance in Canada. It is, however, important to consider that ore processing can result in the creation of by-products that contain radionuclides such as radium-226 (226Ra). Even with the strict discharge regulations in place, there is limited evidence to suggest that the current Canadian regulatory thresholds for 226Ra are protective for aquatic life. This concern underscores the importance of generating toxicity data for 226Ra, as no federal Canadian water quality guidelines for 226Ra currently exist to safeguard aquatic ecosystems. The potential ecological risks of 226Ra are significant due to its high mobility under typical environmental conditions, long half-life (t1/2 ~ 1,600 years), bioaccumulative properties, and similarity to calcium (Ca2+). Considering this, the primary objective of this research was to gather data on the toxicity of 226Ra to the aquatic invertebrate Chironomus dilutus. For this purpose, a partial life cycle experiment was conducted, with larval growth, survival and pupation, and emergence and sex ratio of emerged adults, as the experimental endpoints. In addition, an assessment of oxidative stress as a potential cause of toxicity was performed. These experiments revealed that elevated activity concentrations of 226Ra (25.5 Bq/L) can significantly impact the growth of C. dilutus. However, none of the other nonlethal endpoints were significantly affected by 226Ra exposure, and there was no evidence of oxidative stress in exposed C. dilutus. Finally, 226Ra was shown to adsorb onto the silica sand used as a substrate for all experiments and desorbed following acid extraction.
Description
This is a pre-copyedited, author-produced version of an article accepted for publication in Toxicology Research following peer review. The version of record Charlotte Lacroix-Durand, David Janz, Karsten Liber, Chronic Radium-226 toxicity to and oxidative stress in the aquatic invertebrate Chironomus dilutus, Toxicology Research, Volume 14, Issue 1, February 2025, tfaf001, https://doi.org/10.1093/toxres/tfaf001 is available online at: https://doi.org/10.1093/toxres/tfaf001.
Keywords
ecotoxicology, benthic macroinvertebrate, radionuclides, aquatic invertebrates
Citation
Lacroix-Durand, C., Janz, D., & Liber, K. (2024). Chronic Radium-226 toxicity to and oxidative stress in the aquatic invertebrate Chironomus dilutus. Toxicology Research, 14(1). https://doi.org/10.1093/toxres/tfaf001
Degree
Department
Program
Advisor
Committee
Part Of
item.page.relation.ispartofseries
DOI
10.1093/toxres/tfaf001