Fear of radiation

© Image: Robert Hargraves, PhD
Fig.1 Exposures up to 100mSv in a short time won't overwhelm our immune systems.

Fig.2 People living in areas with high background radiation don't have more cancer.

Fear of radiation is one of the barriers to reconsidering nuclear power. Government agencies have for decades assumed that deaths and other bad effects of radiation on our health follow a model called Linear No Threshold (LNT), in which death and disease is directly proportional to the total cumulative radiation, no matter how low the rate, even as low as the normal background radiation from space and the materials around us. This assumption ignores the data on low exposures (Figs.1&2) and the role of DNA repair in mitigating the damage done by low doses of radiation (Fig.3). Without a repair mechanism, the number of DNA breaks would simply accumulate in a linear fashion, no matter how low the exposure.

© Image: Robert Hargraves, PhD
Fig.3 Natural breakage and repair of our DNA occurs much faster than damage from low levels of radiation.

Fig.4 Eliminating small amounts of radon can be costly.

Over-reliance on the LNT model has led to policies that are very costly, like radon remediation in old homes (Fig.4) and over-reaction to radiation accidents, like the evacuation after Fukushima (Fig.5), which caused far more deaths than the accident itself (Fig.6). It has also led to excessive fear of radiation from medical x-rays and other nuclear medicine procedures which save thousands of lives.

Fig.5 Evacuation following the Fukushima meltdown.

Fig.6 Fukushima death toll over seven years, mostly from the tsunami, some from fear, none from radiation.

The LNT model has also been used to argue against expansion of nuclear power. It has lead to the belief that an accident causing a small increase in radiation over a very large area could lead to a large number of cancers and deaths. A more realistic assessment will show that the danger from nuclear power is much smaller than the public believes, and much smaller than the risks from ever-increasing CO2 in our atmosphere.

Further Reading

For the pro-LNT point of view, see Hold Fast to Linear No-Threshold for Radiation Protection, Bemnet Alemayehu, Senior Staff Scientist, Natural Resources Defense Council, 2016.
"... numerous authoritative national and international bodies have convened committees of experts to examine the issue of LNT ... Again and again, these bodies have endorsed LNT as a reasonable approach to regulating exposures to low dose radiation. ... Opponents of the LNT model simply chose to disregard core research and findings in the field of radiation health physics."

For a rebuttal to these arguments from authority, and an in-depth review of the history, politics, and science of LNT, see Epidemiology Without Biology: False Paradigms, Unfounded Assumptions, and Specious Statistics in Radiation Science, Bill Sacks, Gregory Meyerson & Jeffry A. Siegel, Biological Theory, 2016.
"Belief in LNT informs the practice of radiology, radiation regulatory policies, and popular culture through the media. The result is mass radiophobia and harmful outcomes, including forced relocations of populations near nuclear power plant accidents, reluctance to avail oneself of needed medical imaging studies, and aversion to nuclear energy — all unwarranted and all harmful to millions of people."

For a more recent review from the Health Physics Society, see The History of the Linear No-Threshold (LNT) Model
"The Health Physics Society (HPS) created this series of videos to examine the history of the most controversial question in our field: the LNT model."