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Published on: December 25, 2021
High Natural Background Radiation Areas: A Literature Review that Reveals Systematic Adaptive Response but
Juliette Restier-Verlet1, Clément Devic2, Camelia Bellemou1
1U1296 Unit (Radiation: Defense, Health and Environment), Institut National de la Santé et de la Recherche Médicale (INSERM), Lyon, France.
Abstract:
The natural radiation background contributes to the dose of ionizing radiation received by the whole population. However, the telluric component of the natural background radiation is not homogenous on Earth: while the average effective dose has been estimated to be 2.4 mSv/year worldwide, certain regions are considered as high natural background radiation areas (HBRA). To investigate the specificities of a continuous exposure to low-dose-rate irradiation, we reviewed data of the major HBRA from 98 studies published between 1973 and 2023. Three conclusions were drawn: 1) the dose received by the HBRA inhabitants is much lower than values assessed on hot spots : at Ramsar (Iran), 260 mSv/year were assessed at the highest hotspots but the maximal estimated dose-rate received by inhabitants is 80 mSv/year; 2) when DNA or chromosome breaks, cancer or accelerated aging are used as endpoints, no significant difference was observed between cells from HBRA and non-HBRA inhabitants; 3) conversely, adaptive response effect was systematically observed on ex vivo lymphocytes from HBRA inhabitants when they are exposed to a high dose ranging for 0.25 to 4 Gy. A mechanistic model based on the radiation-induced nucleoshuttling of the ATM protein provides an explanation to these last two conclusions.
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