Radiation Hormesis

Eyasu Kebede
December 6, 2018

Submitted as coursework for PH241, Stanford University, Winter 2018

Introduction

Fig. 1: Artistic Interpretation of Radiation Warning Sign (Source: Wikimedia Commons)

Due to recent and historical nuclear tragedies, the legacy of nuclear energy is tainted. Currently, nuclear radiation has a negative reputation in the general public due to its detrimental health effects. Fig. 1 is an artistic interpretation of warning against radiation.

Hormesis, the hypothesis that the exposure to small amounts of toxic substances results in therapeutic benefit, challenges public perceptions. Radiation hormesis focuses on radiation's potential health benefits. [1] This report will examine hormesis and weigh it against the scientific research.

Is Radiation Hormesis Scientifically Supported?

Discussing the benefits and harms of radiation from nuclear energy is essential because there are more than 640 reactors across more than 32 nations in the world today. In addition, energy need of today outnumbers that of any time in the past. Therefore, this planet cannot afford a mis-perception of the health implications resulting from nuclear energy reactor's radiation output. [2]

At first glance, it may seem that there is some merit to the hypothesis of radiation hormesis. Some research has argued that low doses of radiation exposure can have a protective effect against some cancers. [3] However, these findings have come into question. One example is a study conducted by Brenner et al. which showed that the risk of cancer cannot be completely ruled out at low dose radiation exposure. [4] Brenner et al is a microcosm of the greater scientific community, which largely disagrees with the premise of radiation hormesis.

Currently, one often cited toxicological model to justify regulations on radiation worldwide is the linear nonthreshold (LNT) model. The LNT model states that there is a linear relationship between radiation exposure and the risk that it poses. [5] This model is inconsistent with radiation hormesis because it assumes that all exposurs of are harmful, even low ones. An international cohort study of 308,297 participants conducted by Leuraud et al. shows that deaths to cancer were observed even at low-dose radiation exposure. [6]

Conclusion

It is important to question such hypotheses against the larger scientific literature to avoid policymaking that may lead to adverse health effects; more research is needed to gain a better understanding of the LNT model. An informed view of nuclear reactors is necessary to have a reasonable discussion on creating sensible safeguards as well as address the world's energy concerns.

© Eyasu Kebede. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.

References

[1] R. Macklis and B. Beresford, "Radiation Hormesis," J. Nucl. Med. 32, 350 (1991).

[2] J. M. Cuttler and M. Pollycove, "Nuclear Energy and Health nd the Benefits of Low-Dose Radiation Hormesis," Dose-Response 7, 52 (2009).

[3] T. D. Luckey and K. S. Lawrence, "Radiation Hormesis: the Good, the Bad, and the Ugly," Dose-Response 4, 169 (2006).

[4] D. J. Brenner et al., "Cancer Risks Attributable to Low Doses of Ionizing Radiation: Assessing What We Really Know," Proc. Natl. Acad. Sci. (USA) 100, 13761 (2003).

[5] "Linear-Non-Threshold Model," Canadian Nuclear Safety Commission, April 2013.

[6] K. Leuraud et al., "Ionising Radiation and Risk of Death from Leukaemia and Lymphoma in Radiation-Monitored Workers (INWORKS): an International Cohort Study," Lancet 2, e276 (2015).