Effect of high background natural radioactivity on human mitochondrial DNA in Ramsar, the north of Iran

Vazifehmand, Reza; Saber, Siamak; Takavr, Abbas; Ali, Dhuha Saeed; Saber, Tina; Takavar, Farnaz

doi:10.1504/ijlr.2015.074405

Cited by 1 publication

(1 citation statement)

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“…NBR for humans has four categories: inhalation of radon gas, internal exposure to endogenous 40 K and 14 C, external exposure to terrestrial radiation, and external exposure to cosmic radiation (NCRP 2009). Also, global levels of terrestrial NBR vary dramatically and can range by orders of magnitude higher than found in North America (Ghiassi-Nejad et al 2002; Vazifehmand et al 2015; Nugraha et al 2021). Research programs seeking to eliminate natural radiation sources often conduct experiments deep underground, using the rock overburden to shield from cosmic radiation, which accounts for ~11% of annual human exposure (Liu et al 2018; Esposito et al 2020; Zarubin et al 2021).…”

Section: Introductionmentioning

confidence: 99%

Protracted Exposure to a Sub-background Radiation Environment Negatively Impacts the Anhydrobiotic Recovery of Desiccated Yeast Sentinels

Lapointe,

Laframboise,

Pirkkanen

et al. 2024

Health Physics

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Experiments that examine the impacts of subnatural background radiation exposure provide a unique approach to studying the biological effects of low-dose radiation. These experiments often need to be conducted in deep underground laboratories in order to filter surface-level cosmic radiation. This presents some logistical challenges in experimental design and necessitates a model organism with minimal maintenance. As such, desiccated yeast (Saccharomyces cerevisiae) is an ideal model system for these investigations. This study aimed to determine the impact of prolonged sub-background radiation exposure in anhydrobiotic (desiccated) yeast at SNOLAB in Sudbury, Ontario, Canada. Two yeast strains were used: a normal wild type and an isogenic recombinational repair-deficient rad51 knockout strain (rad51Δ). Desiccated yeast samples were stored in the normal background surface control laboratory (68.0 nGy h−1) and in the sub-background environment within SNOLAB (10.1 nGy h−1) for up to 48 wk. Post-rehydration survival, growth rate, and metabolic activity were assessed at multiple time points. Survival in the sub-background environment was significantly reduced by a factor of 1.39 and 2.67 in the wild type and rad51∆ strains, respectively. Post-rehydration metabolic activity measured via alamarBlue reduction remained unchanged in the wild type strain but was 26% lower in the sub-background rad51∆ strain. These results demonstrate that removing natural background radiation negatively impacts the survival and metabolism of desiccated yeast, highlighting the potential importance of natural radiation exposure in maintaining homeostasis of living organisms.

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