Dr. Ed Calabrese has published additional installments in his continuing effort to illuminate the methods by which the 16 member Genetics Committee of the 1956 National Academy of Sciences Biological Effects of Atomic Radiation committee altered history. That small group of colleagues, chaired by the man who approved their research grant requests during the period from 1932-1959, effectively shifted radiation risk assessment from the threshold model to a “no safe dose” model for ionizing radiation.
Using archived original source material, including meeting minutes and direct correspondence among committee members, Calabrese has uncovered evidence showing how the committee produced a report designed to influence national policy and standards setting using a process that carefully selected desired answers, eliminated work that provided a greater range of uncertainty, and failed to report the existence of documented dissent that was expressed in clear language in a signed letter.
Calabrese’s recently published installments about the way the “no safe dose” model was created and imposed include:
- An abuse of risk assessment: how regulatory agencies improperly adopted LNT for cancer risk assessment a letter to the editor of the Archives of Toxicology published online on January 18, 2015.
- LNT’S FAILED HISTORY: An Abdicated Responsibility – How the US NAS BEAR I Committee Genetics Panel Failed To Assess LNT Prior To Recommending Its Use by US Regulatory Agencies supplementary material for An abuse of risk assessment
- Cancer risk assessment foundation unraveling: New historical evidence reveals that the US National Academy of Sciences (US NAS), Biological Effects of Atomic Radiation (BEAR) Committee Genetics Panel falsified the research record to promote acceptance of the LNT a letter to the editor of the Archives of Toxicology published online on January 20, 2015.
- Scientific Misconduct by the U.S. National Academy of Sciences in Recommending LNT for Risk Assessment supplementary material for Cancer risk assessment unraveling
As Calabrese’s letters and papers document, before the NAS BEAR committee was formed in 1955, Hermann Muller, Curt Stern and a handful of other geneticists had been promoting the no threshold dose response model in various radiation protection advisory committees for several decades. Their efforts had been balanced by specialists in other biology and medical fields who pointed out that there was no evidence of harm below reasonably well-defined thresholds and that they were adequately protecting human health by establishing standards that were an appropriately small fraction of the doses where measurable harm first develops.
In the decision documents of several of those committees, one can find statements indicating that the opinions of the geneticists were not suppressed or ignored; the documents include statements about the assumption that every dose carries some risk “from a genetics perspective.”
For the NAS BEAR studies, Detlev Bronk, who was both the President of the National Academy of Sciences and a member of the board of trustees for the Rockefeller Foundation — the requestor and funder of the study — created a separate Genetics Committee that included only a few non geneticists. He assigned Warren Weaver, a former math professor and the director of the Rockefeller Foundation’s natural sciences program, to be the chairman of the committee.
Without any debate, the committee decided that the proper model to use in risk assessments for radiation was a linear, no-threshold model. After agreeing to use a linear model, the committee focused its efforts on computing the slope of the line so that their report could provide numerical recommendations for dose limits.
The risk assessment method Warren Weaver chose was to ask each of the 12 geneticists on the panel to provide their expert analysis, document their methods, assumptions and calculations and provide a best estimate with lower and upper confidence intervals. People who are familiar with risk assessment will recognize that Weaver was using an early version of the technique often described as “expert judgement elicitation.”
There is nothing wrong with using that method. In fact, it is often the only available method in fields where there is a great deal of uncertainty and a paucity of data on which to make informed judgements.
The problem that Calabrese has identified, however, is that the Genetics Committee leadership was so focused on its directive to help reduce public uncertainties about radiation health effects that it apparently refused to listen to the scientists on the committee who pointed out that there was a great deal of uncertainty and no data at all in the dose rates of interest.
The Genetics Committee leaders were apparently uncontaminated by doubts; they knew that their report would conclude that there was no safe dose of radiation. It’s quite possible that decision was made before the study committee was formed.
The only reasonably valid data on genetic effects of radiation available to the committee in 1955-1956 came from Muller’s Drosophila (fruit fly) experiments. Those experiments did not test any levels below about 50 rad (500 mGy) given to the flies over a three-week period. The Atomic Energy Commission had developed some preliminary data using experiments on mice, but only a few members of the committee had access to that information.
Here is how James V. Neel, a geneticist from the University of Michigan, responded to Warren Weaver’s request to provide a numerical estimate of the risk associated with a dose of 10 Roentgen to the gonads. (See Calabrese, Scientific Misconduct by the U.S. National Academy of Sciences in Recommending LNT for Risk Assessment, p.7)
On April 6, 1956 he [Neel] specifically addressed his concern with Chairman Weaver (Neel 1956a):
“The geneticist has social responsibilities, but he also has responsibilities as a scientist. One is that in an area as critical as this one is, he must beware of letting his conjectures get too far in advance of his facts. It is to me an exceedingly tenable position, having stated the general genetic argument, to say flatly that we know so little about the quantitative aspects.” In fact, Neel was so adamantly opposed to the decision to develop and provide such genetic estimates of damage that he wrote Weaver on March 8, 1956 stating that he would “go down with flags flying and guns booming to the last” (Neel 1956b).
Three of the 12 experts from whom Weaver elicited judgement did not provide any answers. The other nine did. However, the published report only included the results from six of the nine, eliminating without three completed expert estimates that would have increased the reported range of uncertainty from the 100 fold that the committee reported to something more than 4,000 fold. During the deliberation period, here is how James Crow, the man that Weaver had assigned to compile the expert judgements, described his dilemma. (See page 11.)
The limits presented on our estimates of genetic damage are so wide that the reader will, I believe, not have any confidence in them at all.
The method selected for narrowing the range of estimates was to decide not to include the inconvenient expert judgements that greatly expanded the uncertainty range of genetic effects of radiation. The report says nothing about why three of the experts who were asked to provide estimates either failed to respond or refused to respond because they stated that the task bordered on dishonestly asserting more certainty than supportable by the known data. These are the actions that Calabrese has properly labeled as scientific misconduct.
Unsurprisingly, the buffed up report from the Genetics Committee received a great deal of publicity. It helped that Arthur Sulzberger, publisher of the New York Times, was one of the Rockefeller Foundation trustees who had asked the National Academy of Sciences to provide its independent opinion about radiation health effects while lending its highly credible name to the effort.
The well-planned promotional effort helped to ensure that the Genetics Committee report received wide attention, while the confidence that the committee reported in its estimates added to its credibility. The warnings and numbers that it provided were welcomed by the growing segment of the scientific community that was involved in political actions to halt nuclear weapons testing. One of their chosen levers was increasing fear of radiation, another was creating distrust in the Atomic Energy Commission and its repeated reassurances that the testing produced doses that were not harmful to people.
In what was most likely an unintended consequence of the report, its findings probably intensified the ill-treatment and ostracizing of the Japanese hibakusha, the people exposed to radiation as a result of the atomic bombs dropped on Hiroshima and Nagasaki. After all, it asserted that radiation exposure did unrepairable harm to genetic material and increased the probability of defects and mutations in future generations. Who would want to fall in love with someone who scientists have asserted would produce mutant children, especially in a society where generational responsibility is so strong?
Increasing fear of radiation with dire warnings about effects of increasing use of radiation and radioactive materials on future generations also aligned with the interests of the sponsoring foundation. Fears about inevitable genetic mutations and irreversible damage, along with committee recommendations for tight controls on nuclear power plant design, operations and siting helped to ensure that its vast holdings of stocks and bonds in Standard Oil and its progeny would not be harmed too much by competition from a rapidly growing atomic energy enterprise.