Experimental insights into high background radiation: reduced cancer risks in a murine model study

Authors

• S. M.J. Mortazavi, Ionizing and Non-Ionizing Radiation Protection Research Center (SUMS)
• M. Arshadi, School of Medicine
• B. F. Baha'addini Baigy Zarandi, School of Medicine
• J. S. Welsh, Edward Hines Jr. VA Hospital
• H. Mozdarani, Tarbiat Modares University
• M. Haghani, School of Paramedical Sciences
• N. Jooyan, Ionizing and Non-Ionizing Radiation Protection Research Center (SUMS)
• S. Nematollahi, Bam University of Medical Sciences
• Negar Azarpira, Transplant Research Center (SUMS)
• Lembit Sihver, The University of Texas Rio Grande Valley

Document Type

Article

Publication Date

10-1-2025

Abstract

Background: Natural background radiation varies geographically and has potential implications for cancer development. High-level natural radiation areas (HLNRAs), like Ramsar, Iran, offer unique opportunities to study the biological effects of radiation exposure. This study investigates the relationship between high background radiation and tumor progression in a murine model. Materials and Methods: Thirty-two C57BL/6 mice were exposed to varying levels of natural radiation (0.097 μSv/h to 9.24 μSv/h) for two months, simulating conditions in Ramsar. Mice were divided into four groups based on radiation intensity. After exposure, 1106 B16-F10 melanoma cells were injected subcutaneously, and tumor growth was monitored for 24 days. Tumor morphology was assessed using Magnetic Resonance Imaging (MRI), and survival rates were recorded. Statistical analyses included mixed-model and Kaplan-Meier methods. Results: Tumor volume and growth rates were significantly reduced in groups exposed to the highest radiation levels (100X Bkg). Mice in this group also exhibited the highest survival rates (100%) compared to the control group (55.6%). Tumor reduction and disintegration were observed, especially in female mice, suggesting a potential protective effect of elevated radiation exposure against melanoma progression. Conclusion: Findings challenge the Linear No-Threshold (LNT) model by demonstrating that high background radiation may not correlate with increased cancer risk. Instead, elevated radiation levels appear to confer protective effects against tumor growth in this murine model. These results highlight the need to reassess radiation safety standards and explore the complex interplay between radiation and cancer biology.

Comments

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

Recommended Citation

Mortazavi, S. M. J., M. Arshadi, B. F. Zarandi, J. S. Welsh, H. Mozdarani, M. Haghani, N. Jooyan et al. "Experimental insights into high background radiation: reduced cancer risks in a murine model study." International Journal of Radiation Research 23, no. 4 (2025): 987-994. http://doi.org/10.66224/ijrr.23.4.22

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License

First Page

987

Last Page

994

Publication Title

International Journal of Radiation Research

DOI

10.61186/ijrr.23.4.22