Low-dose radiation: LNT vs. hormesis

By Bill Sacks and Greg Meyerson What we are about to say flies in the face of the conventional wisdom. There is no automatic reason for anyone to believe or trust our comments, so we provide some sources at the end that allow the reader to do further investigation. And for the sake of brevity…

By Bill Sacks and Greg Meyerson

What we are about to say flies in the face of the conventional wisdom. There is no automatic reason for anyone to believe or trust our comments, so we provide some sources at the end that allow the reader to do further investigation. And for the sake of brevity we will for the most part make categorical statements, claims which rest on voluminous evidence that the reader may have to study, just as we have done, in order to get over the speed bump that the conventional wisdom invariably represents. Therefore consider this an introduction to the topic of radiation “hormesis,” intended to open doors, rather than an attempt to convince–-an impossible goal of a single commentary, particularly under the circumstances.

Hormesis – the stimulation by some agent, such as radiation, of biological responses that are protective against damage done by that agent. It has the same etymological root as hormone, which is a molecule secreted by a gland to stimulate a response in some other part of the body.

The biological response of people (as well as other animals and plants) to ionizing radiation (the kind produced by nuclear processes and x-rays or CT scans) is one with three phases:

• the response to too much radiation,

• to a healthy amount of radiation

• to a radiation deficiency

The second of these is the one that involves the protective response. In light of repeated assertions that all ionizing radiation is harmful no matter how high or how low the dose, the existence of a beneficial health effect may be surprising. But nearly a century of laboratory experimentation and epidemiological observation of both humans and animals supports the protective response region and contradicts the conventional wisdom. Why then does the concept that all ionizing radiation is harmful hang on with such tenacity, and how did it gain a foothold against all evidence to the contrary?

In the early part of the 20th century, radiation (for convenience we will drop the word “ionizing” but it should be understood for the purposes of this commentary) regulations by government agencies–regulations which were recommended by certain research organizations, but not all–allowed exposures to much higher doses of radiation than became the rule after the dropping of the “atomic” bombs on Hiroshima and Nagasaki in August 1945.

The arms race that followed the war, especially between the US and the Soviet Union, gave rise to the testing of more and more nuclear weapons. At first this testing was in the atmosphere. Open-air testing released radioactive materials from the explosion that were massively diluted and carried by the wind to distant places. The material included radioactive fission products as well as the original uranium or plutonium that constitute the initial explosives. Doses and dose rates caused by exposure to this material were, with very few exceptions, tiny. Scientists responsible for public health protection computed that there was no risk to the public from such small exposures.

A campaign began to stop the testing of nuclear weapons in the atmosphere. Scientists who recognized the dangers of nuclear war wanted to convince masses of people to protest their respective governments against both the testing of nuclear weapons and the nuclear arms race. In pursuit of this goal, they were willing to lie about the dangers of fallout and exposure to low or moderate amounts of radiation from radioactive material. Many of the scientists involved in the political effort to slow the arms race and halt testing were involved in the Manhattan Project and expressed regrets for their participation in the creation of nuclear weapons because of the death and destruction caused by the use of bombs at Hiroshima and Nagasaki.

The first recorded lie in this campaign was offered in 1946 by Hermann Muller as part of his acceptance speech for the Nobel Prize he received for his earlier work on radiation-caused mutations in fruit flies. He claimed there was unequivocal evidence that all radiation was harmful and proposed the theory that individual “hits” produced mutations, but his statement has often been repeated out of context. Here is a more complete quote:

These facts have since been established with great exactitude and detail, more especially by Timoféeff and his co-workers. In our more recent work with Raychaudhuri (1939, 1940) these principles have been extended to total doses as low as 400 r, and rates as low as 0.01 r per minute, with gamma rays. They leave, we believe, no escape from the conclusion that there is no threshold dose, and that the individual mutations result from individual “hits”, producing genetic effects in their immediate neighborhood.

(Emphasis added.)

Even though he provided some caveats and context, Muller was in possession of information that he knew disproved the assertion. One of his colleagues had just obtained an experimental result showing that low doses of radiation actually were protective, which Muller had acknowledged one month prior to his acceptance speech, saying in a note that when he returned from Stockholm they would have to look into this further. (Ref: Callabrese, Edward, Muller’s Nobel lecture on dose–response for ionizing radiation: ideology or science?, Archives of Toxicology, Dec. 2011).

Muller was thus the first to deliberately exaggerate the dangers in order to create a climate of fear. This lie, this exaggeration, is still with us to this very day, and pervades the underlying position of virtually all governmental regulatory agencies around the world that deal with radiation – as well as the position of those economic interests (particularly fossil fuel companies), organizations, and individuals opposed to nuclear energy.

The lie became embodied in a demonstrably false expediency that is called the linear-no-threshold (LNT) model, which states that damage due to radiation is harmful and linear down to zero dose, with no threshold below which there is no harm. Linear means that, for example, twice as much radiation, no matter how low the dose, creates twice as much damage to a population, mainly in the form of numbers of cancers and deaths. The absence of a threshold is sometimes admitted by advocates of LNT to be a mere expediency. This is particularly true of the series of reports published by the BEIR (Biological Effects of Ionizing Radiation) committee of the National Research Council (part of the National Academy of Sciences).

But rather than announcing that there is no evidence to support this model, LNT advocates, including the BEIR committee, assert that in order to demonstrate that LNT is true, the sample sizes of people exposed to low doses would have to be impractically large for statistical significance to be obtained. This incidentally argues, without their intending it, that any statistical significance so achieved would indicate very little clinical significance in the low-dose range if LNT were true.

They even go so far as to claim that the actual data in the low-dose range are “consistent with” LNT. This latter claim rules out hormesis a priori, so that evidence that is far more “consistent with” hormesis (as the sources mentioned at the end, both directly and indirectly, will testify) is ignorable as such, and is co-opted to their purposes with the statement that the evidence is “inconclusive.” In short, they rule out hormesis by fiat rather than by scientific evidence. They are forced to this maneuver since the evidence supports hormesis and contradicts LNT. The only reason that LNT is widely accepted is that virtually all political power stands behind LNT, so that it has long been the default position. This is not science.

But more recently a growing group of researchers into the effects of radiation at various doses, and others who support their efforts, have begun campaigns to undo the very harmful effects of the radiophobia–-an unwarranted fear of radiation–that has arisen from insistence on the LNT assumption. The media and certain publicists stoke radiophobia because “fear sells.” There are even scientists who seek the prominence that opposition to radiation earns them.

Radiophobia not only fails to prevent harm, but actually causes harm–and very great harm at that. First, it produces a refusal by many people to undergo potentially life-saving radiation, from things like x-rays and CT scans to nuclear medicine studies, for the purpose of diagnosing illnesses and injuries–illnesses such as breast cancer that can