Wednesday, June 27, 2012


Arnie Gunderson just provided a great summary of one of the important differences between the ICRP (with the NCRP) and the ECRP:

According to Arnie Gunderson, the ICRP, or International Commission on Radiological Protection, averages radiation dose over the entire affected organ and does not look at the targeted, focused effects of radiation internal to the body.

In contrast, the ECRP addresses the specific targeted effects of the radiation dose in a localized area impacted by the particle or gamma ray.

MAJIA here: I believe the ICRP model also fails to look at the relative biological effects of gamma, beta particles, and alpha particles. I'm not sure of the extent to which the ECRP model incorporates the relative effects.

The true extent of damage produced by ionizing radiation, particularly alpha and beta particles, has been hidden by complicated language and competing risk models since physicists, chemists, and geneticists started arguing about the effects back in the 1940s. 

Today the big competitors are those identified by Gunderson:
1.) the ICRP and NCRP
2.)  the ECRP European Commission on Radiation Protection

What is ironic about this debate over dose effects outlined by Gunderson is that it essentially started in the late 1940s, although the exact issues have changed across time with new understandings of genetics.

The irony stems from the fact that in the 1930s, nearly everyone in American who read the papers knew that ingested radiation kills, painfully, because of some very high profile trials about people poisoned by radium.

Thus, the debate about the internal effects of radiation was political from the start. 

When the AEC Chairman declared that there was no health effects from low doses of radiation, geneticists rebuked him publicly.

Jacob Hamblin in The Journal of the History of Biology (vol 40.1 2007 147-177)  describes how the first major study on the biological effects of radiation conducted by the National Academy of Science (NAS) in 1956, the BEAR study, was fraught with disputes between (1) geneticists who saw all levels of ionizing radiation as increasing harmful mutations and (2) other atomic scientists, especially those connected to the Atomic Energy Commission (AEC), who found no conclusive evidence of long term damage from atmospheric fallout (147-148) and persisted in equating nuclear fallout with natural background radiation (152).

According to Hamblin, the Rockefeller Foundation that funded the first BEAR study also helped control media dissemination of its major findings, shaping public opinion about atmospheric testing specifically, and radiation safety, more generally.

Production of the BEAR report was fraught with political infighting.  In the early 1950s, the Secretary of the Atomic Energy Commission publicly denied harmful effects from "low levels" of exposure to radiation (since in the AEC's view, radiation was essentially just sunshine--beta and gamma didn't calculate in their universe).

A prominent geneticist, A. H. Sturtevant of  California Institute of Technology in Pasadena, was so irate about the idea of a permissible dose that he wrote an essay published in Science titled, "Social Implications of the Genetics of Man" (Sep. 1954 vol 120), in which Sturtevant demonstrated the fallacy of permissible dose (p. 406). The final sentence of Sturtevant's essay is a direct challenge to Chairman Strauss of the Atomic Energy Commission and reads as follows: "I regret that an official of such responsibility should have stated that there is no biological hazard from low doses of high-energy irradiation" (407). As a member of the genetics subcommittee of the BEAR report, Sturtevant clashed with Atomic Energy Commission members who persisted in the no effects mantra for low levels of exposure.

Although the study was published under the auspices of the National Academy of Science, the Atomic Energy Commission (AEC) controlled access to classified information on atomic effects, controlled access to the media, and indirectly controlled the final version of the report that was published in Scientific America, aimed at public consumption. There were also key AEC members in the study who influenced how findings were discussed in the final report. The presence and privileged status of AEC personnel shaped the final report in significant ways because of their insistence on a threshold for “safe exposure,” their institutional privileges, and their  access to, and visibility within,  in the public spotlight , as contrasted with NAS members, particularly the NAS geneticists who did not participate in publicizing the report’s findings....

. . . .

Even the effects of radiation on people in Japan was biased by a failure to recognize symptoms of radiation poisoning that existed in the absence of the symptoms of acute exposure.

Those representing the consensus seeking ICRP and NCRP sought ways to address internal dose, but only in ways deemed acceptable to nuclear industry advocates
 Example: NCRP MISSION "...The Council's mission also encompasses the responsibility to facilitate and stimulate cooperation among organizations concerned with the scientific and related aspects of radiation protection and measurements."

The scientists/physicians who disagree about compromising to serve the interests of the nuclear industry and thus argue that ECRP model, which looks at targeted effects, better predicts true risk.


Arnie Gunderson is making an important stand on this issue. 


I have a very long blog post about some important differences between the models.

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