Nuclear News,
January 2000

      When an audience member questioned whether support of the linear no-threshold (LNT) hypothesis, also known as LNTH, amounted to nothing more than "scientific fraud," an explosion of agreement came from some panelists at the "Low-Level Radiation Health Effects" session during the ANS Winter Meeting, held November 14-18, 1999, in Long Beach, Calif.

     The LNT, the recommendation upon which national and international radiation protection policies are based, holds that any amount of radiation down until zero dose could have a negative effect on living organisms. Detractors of the LNT, including the panelists at the session, counter that studies have shown that certain lower levels of radiation have no detrimental effect and in fact are beneficial.

     Scientific evidence has proved that the LNT "is not consistent with the biology as we know it," according to Myron Pollycove, M.D., one of the panelists and special assistant to the deputy executive director of operations of the Nuclear Regulatory Commission.

     There also are charges that data supporting the LNT have, as the panelists claim, been substantially misrepresented, that good data exist that contradict it, and that billions of dollars are wasted in the unnecessary cleanup of sites to background levels.

    All these factors seem to give support to James Muckerheide, session organizer, who said that the effort to retire the LNT "is not something that we feel we are stretching the bounds on."  The challenge in this regard is to keep promoting data that contradict the LNT, the panelists agreed.

     "There's been a lot of effort to recognize that the LNT is not the right model to use scientifically for what's going on with radiation," said panelist Theodore Rockwell. He noted that Sen. Domenici pushed for funding for a new low-level radiation research project to be conducted by the Department of Energy (a 10-year DOE study on health risks of low radiation exposures is under way — see NN, Oct. 1999, p. 68), and that the American Nuclear Society has recently released a position statement on the health effects of low-level radiation (NN, Aug. 1999, p. 108). The ANS position statement declared that there is "insufficient scientific evidence to support the use" of the LNTH.

     But the LNT won't go away without a long struggle, admitted Rockwell, a founding director of Radiation, Science & Health, Inc. "If you're talking about the LNT hypothesis, you'll be handed a 300-page report from the NCRP [National Council on Radiation Protection], who defend it, or the BEIR [Biological Effects of Ionizing Radiation] committees, who defend it. This report, with equations and figures, is a pretty imposing challenge," he said.

     The bottom line, the panelists agreed, is not in determining whether the line in the LNT is indeed linear or exactly at which point a threshold exists, but in doing away with the hypothesis that claims that low levels of radiation are harmful, as its supporters insist.

     Panelist Al Tschaeche, CEO of Nuclear Standards Unlimited, related a story about his drive up from San Diego where he was slowed by an accident on the freeway: "It occurred to me as I was sitting in the car waiting to go that what I was doing in driving up here was almost infinitely more hazardous than if I were to get a few millirem of radiation."

     "From a physician's point of view and a common sense point of view, we don't know of anything biologically that works on a linear basis," said Pollycove. Pollycove has been with the NRC for eight years, after years as head of nuclear medicine and the clinical laboratory at the University of California-San Francisco. He also formerly was head of nuclear medicine at San Francisco General Hospital. Pollycove, as a medical doctor, admitted that for the 11 years he worked in nuclear medicine, he never questioned the LNT and assumed that the people spending their time and money issuing reports on it had a credible scientific basis.

     "But I was shocked when I had the time to look into it" and realized that there was no proof behind the hypothesis, he said.  Using examples from the world of physiology to support the argument against the LNT, Pollycove recounted that too much physical exercise can wear out the body, while too little can cause it to atrophy. The right amount, however, benefits the body and makes it stronger. Likewise are the effects of mental stress on a human: too much can cause a nervous breakdown, too little can cause the mind to vegetate. In the same category are poisons, he said, from arsenic to strychnine to selenium, which are all toxic if taken in large doses, yet have beneficial uses if taken in very small amounts. "It is odd, then, that somehow radiation should become the sole exception to this rule," he said.

     In explaining the logic that contradicts the LNT, Pollycove said the human body endogenously creates 200 million times more "free radicals" (disease-causing mutations) per day than does a normal daily dose of back-ground radiation, which, he said, is one-tenth of a centigray (cGy), or rad. Each day, he explained, 1 billion free radicals are produced in each cell of the human body, but only 1 in 1000 get to the DNA to cause damage to the body. These mutations are the same as free radicals generated by radiation. The free radicals in the DNA are normally removed and damage repaired by the body's immune system, which generates antioxidants that fight the free radicals.  And so, while it is accepted that a healthy human body naturally fights off billions of mutations endogenously created per day (in addition to the daily dose of background radiation) without any deleterious effect, the LNT theorizes that even a fraction of the daily dose of background radiation can be harmful, according to Pollycove. 

     The illogic of this "has all been ignored," he said. On the contrary, Pollycove said, when background radiation is increased tenfold, to 1 cGy, as was established in UNSCEAR '94 (United Nations Scientific Committee on the Effects of Atomic Radiation), low-dose radiation has proved to stimulate antioxidant production. When antioxidants are increased, he said, "we wind up with fewer mutations per day, which adds up to less aging per day, longer life, fewer degenerative diseases that are associated with these mutations, and less cancer." This process has led in the last three years to the coining of the term "radiation hormesis," according to Pollycove, which means that low-level radiation "stimulates the organism, stimulates antioxidants
that prevent damage to DNA, stimulates enzymes that repair damage, and stimulates the immune system." Although the scientific community has yet to determine the "why" behind beneficial stimulation, Pollycove admitted, what is certain at this time is that "certain genes are turned on by ionizing radiation."

     In addition to talking about studies where laboratory mice fought off diseases after receiving low-dose radiation treatments, Pollycove referenced a pair of clinical trials, the first at Harvard University in the 1970s and the second conducted in Japan in the early 1990s, that showed how low levels of radiation stimulated immune systems to fight cancer. In both trials, non-Hodgkins lymphoma patients were treated to low doses of radiation using linear accelerators, in addition to the patients' usual treatment of chemotherapy and local radiation for large tumors. In each case, over a period of five weeks, each patient was given a total dose of 150 cGy. During the treatment, Pollycove said, results showed that the low-dose treatments stimulated the immune systems of the patients and they experienced no symptomatic side effects.   After four years, the results of each trial showed that none of the patients had died; after nine years (results from the Harvard trial only) more than 80 percent of the patients were still surviving, versus the normal 60 percent survival rate for patients who receive only chemotherapy and localized radiation.  Yet, Pollycove wondered, why were these two clinical trials conducted 20 years apart when the results of the Harvard trial in the 1970s showed such a distinct improvement in the patients? "The only explanation I have is that there was money for research from the pharmaceutical companies for chemotherapy, but there wasn't similar funding for radiation," he said.

     Rockwell related his take on the LNT: An overwhelming amount of evidence that contradicts it is "not being utilized in the study of public policy," he said. Quoting partially from NCRP 121, which lays out the scientific case for the LNT, Rockwell read: "`Few experimental studies and essentially no human data can be said to prove or even provide direct support for the [LNT]."' Yet, he said, the data that challenge the LNT "are being ignored." An illustration of how LNT contradiction is being ignored took place in October 1998, when the NCRP SC 1-6 report that looks at the LNT came out in draft form for public comment, Rockwell said.

     One of the vehicles for commenting was through an advisory committee set up by the NRC, through which Rockwell and other LNT detractors gave comment. Prior to the draft report's release, the NRC advisory committee formally expressed concern to the NCRP that all comments should be regarded objectively in the report.

     Yet when the draft report was released, according to Rockwell, none of the LNT detractors' comments had been taken into account. "We tried to approach the NRC to follow up on that," he said, "but in response the project officer made a short but impassioned speech that it would be improper to tell [NCRP] what to do. Besides, he said that they'd written a wonderful report and everybody thought it was just grand."

     But all is far from grand in the debate over the LNT, according to Rockwell. There have been other areas in which scientific data are being suppressed by bodies such as the NCRP, the BEIR committees, and the International Council for Radiation Protection (ICRP), he said. Rockwell declared that all of them have ignored or misinterpreted a high-dose radiation workers study, a nuclear ship-yard workers study, and a series of other studies that have shown that low-level radiation is either harmless or beneficial.

     Not only are data being suppressed, but evidence in support of the LNT has been "inappropriately juggled," Rockwell said. As an example, he talked of graphs in support of the hypothesis that show a curve in which data points come down into the beneficial area for certain low doses and then go back up into the harmful area as dose is increased. "What they've done in a couple cases is to take the data — such as the nuclear shipyard workers study, because most of your data are in the low levels — and since they don't like to see the points drop below the line [into the beneficial area], they take all the data from zero to 50 rad [cGy] and call it a single point and squeeze it above the curve [into the harmful area]," he said. Rockwell called this misrepresentation of data "not proper, and when it changes the answer from yes to no, it's no longer a trivial matter."

     Supporting Rockwell's stance is Senator Domenici, who has expressed belief that data are being improperly examined, according to Rockwell. He said that Domenici has prompted an investigation of the LNT in the form of a 10-year DOE research program. In addition, Domenici requested that the U.S. Government Accounting Office study the LNT and evaluate whether it is the proper application of public policy. The GAO is expected to release its report by June 2000. 

     Other encouragements, according to Rockwell, include ANS's recent position statement on low-level radiation health effects. Rockwell said that he and others are trying to get this statement amended to include the following "key sentences": 1) "In presentations to the ANS and to policy making groups, it has been shown that some reports that claim to support the LNT substantially misrepresent the data." 2) "A large body of credible, replicable statistically significant scientific data exists that directly contradicts the LNT." 3) "ICRP, NCRP, and BEIR reports fail to adequately consider this I evidence." 

     The paradigm is the problem, according to Tschaeche. The paradigm in the minds of the public is that radiation, in any amount, equals harm. "The thing that drives the pro-LNT people is fear," he said. "They're afraid that if they go away from this idea that they've had-that a little bit of radiation may be harmful-that someday they'll realize they were wrong from going away from it in the first place." 

     Before 1968, the United States and the rest of the world worked to the radiation standards that existed at the time, Tschaeche said. "I was at Westinghouse then and we worked to 5 rem per year," he said. "There was no ALARA [as low as reasonably achievable]. ALARA was a concept that health physicists had, but it wasn't a regulatory requirement. And everything was fine."  What happened in 1968, he said, was that an analysis was done that concluded that the effluent levels from one nuclear reactor in the Midwestern United States would kill thousands of people if its releases resulted in exposures of 170 millirem per year to the general public. That study, according to Tschaeche, was simply a hypothesis. But giving support to the hypothesis were the radiation data that existed at the time, which consisted of results from the Japanese atomic bomb [high-dose] studies. "We didn't have any low dose statement," Tschaeche said. "So somebody had to come up with the idea of how to tell what are the effects that low doses would have on people." And so the LNT appeared, he said, although he was unsure of exactly when or how it first arrived, and that perhaps it was just a refinement of earlier radiation-protection statements. The only problem, he said, was that the LNT's only purpose was to be for the setting of radiation protection standards, and not as a representation of reality.

     What happened next, according to Tschaeche, was that anti-nuclear groups latched on to the LNT to help orchestrate their cause through the media. (Tschaeche said he once wrote a letter to Time magazine complaining about a reporter's bias in an article. Time wrote back, he said, replying that "total objectivity" in their magazine articles was "not only impossible to achieve, but undesirable as well.") That orchestration has helped lead to the current belief that "one proton will kill you. And the public believes it," Tschaeche said. The result, he continued, is a public policy that results in "spending billions to clean up sites down to background." 

     And so while the NCRP and ICRP make recommendations based on the LNT, it is governmental agencies and organizations like the American National Standards Institute (ANSI), ISO (International Organization for Standardization), and International Atomic Energy Agency that set standards, he said. 

     The task, then, is doing something about the standards. Tschaeche has started a standards activity in the ISO, and is planning to submit to ANS a standard on permissible radiation levels to be put into the ANSI standards system. "If we had this standard for dose that is reasonable that didn't have the LNT in it, maybe we could get the government to turn its head around and go in the right direction," he said. 

     More than 100 years ago, since 1896, science was using low levels of radiation to stimulate the immune systems of animals to cure infections, said James Muckerheide, the state nuclear engineer with the state of Massachusetts Emergency Management Agency.  Yet those scientists had no knowledge of the molecular biology and cellular response effects that exist today. So, with the body of knowledge now in place and the current investigation into the LNT, it is only a matter of time before "science comes around," he said.

     Muckerheide has been instrumental in leading the effort to look at LNT feasibility. He first pulled data together in 1993-1994 during an assignment for the governor of Massachusetts. Later in 1994, he initiated the first session at an ANS meeting on the subject. 

     Muckerheide provided an overview of some of the activities taking place in the investigation of the LNT. In 1997 the Wingspread Conference was held, consisting of about 50 leaders and representatives from many national and international radiation protection institutions, including the ICRP, NCRP, NRC, and U.S. Environmental Protection Agency. The attendees at that meeting, according to Muckerheide, acknowledged that no data exist that support adverse health effects below at least 10 cGy (10 rem) and that hundreds of billions of dollars in environmental cleanup costs were producing no public health benefits. (A follow-up meeting to Wingspread was scheduled for December 1-5, 1999.)

     Coming out of the 1997 Wingspread meeting, Muckerheide said, there should have been a new initiative in recognition of the acknowledgement, according to the recommendations of that conference. But that new initiatives never occurred, he said, which was part of the reason why Senator Domenici procured funding for DOE research and requested work on the upcoming GAO report.  Another meeting, this one of the International Radiation Protection Association scheduled for May in Hiroshima, Japan, Muckerheide said, will possibly have a paper submitted by Roger Clarke, head of the ICRP. According to Muckerheide, Clark will propose that the LNT threshold be lowered from 10 millirem to 3 millirem, which, Muckerheide noted, will still have the effect of saying "that very low levels of radiation can kill you, but at some level we'll just decide that it's not worth chasing anymore."

     Besides saving billions of dollars on unnecessary cleanup of sites, retiring the LNT could also result in enhancing the appeal of nuclear energy, Muckerheide said. "At a basic pressurized water reactor plant," he said, "30 percent of the investment in the plant is to generate power and 70 percent is to provide safety.  Certainly you'd expect to protect the core as an intrinsic part of safety. But if you use risk-informed decision-making so that you don't try to prevent every radioisotope from leaving containment but stay within reasonable bounds of assured safety, there are many things that can be done to bring nuclear [power] to a more cost-effective level."

     "Nuclear medicine could also benefit," he said. "The costs in nuclear medicine have been driven largely by the regulatory burdens and problems with producing and handling isotopes and controlling nuclear material," he said. Muckerheide related a story about a visit to a Toronto hospital that had its nuclear medicine department on the 18th floor. Below, on the 6th floor, were giant tanks able to receive waste from patients having iodine-131 treatments. "They had these giant tanks to hold the waste streams for an eight-day half-life of iodine-131 at a cost of many hundreds of thousands of dollars," he said. "At the same time, there were complaints that there was contamination in the waste pipes that came down from the 18th floor to the 6th floor.
Now they've got to begin shielding the pipes because there's residual 8-day half-life I-131 in them. So there's an aspect of this that we don't always consider in terms of cost."  

     Muckerheide also wondered whether the nuclear industry was taking the right path when it talks of the protections it has in place for radiation instead of, in many cases, stressing the low risk levels of certain wastes. "We're taking radioactivity that's simply going to decay away and be a small fraction of an environmental source, and we're treating it as though it needs a [high] level of security," he said. "We don't tell people that radiation at low doses is safe. We tell them it's safe because we've spent billions of dollars assuring it's safe by securing it, and when transporting it."

     Radiation, Muckerheide concluded, is intrinsically part of our background environment. It is what we grew up in and it is part of our biological process. "So how a small amount of radiation that is well within the natural variations in nature could be intrinsically harmful is really hard to fathom," he said.

     Theodore Rockwell worried that the industry will continue being its own worst enemy in trying to explain that not all radiation is harmful. "When we talk about the public's irrational fear of radiation, we create that fear," he said. "Ralph Nader or Jane Fonda didn't invent the China Syndrome or the LNT."  He told a story of how the DOE had once issued a press statement, "out of the clear blue sky, for no particular reason," to announce results of a six-year study on what the effects would be of transporting shielded weapons radwaste across the country to Yucca Mountain. "The punchline was that they were going to kill 23 people by irradiation by subjecting millions of people with a few millirems of radiation," he said. "It's like saying that we know that 100 aspirin will kill you, so if we give each person in the country one aspirin [1/100 of the 100-aspirin dose], we're going to kill 2.5 million people" [ 1/100 of the 1990 U.S. population of 250 million].

     It is that kind of reasoning that ends up being used against all things nuclear, Rockwell continued. "I've been up against antinuclear people who open their statements by saying, `Using the government's own methods for calculating these things, this will lead to so many cancers,"' he said. A better way of educating people has to be found, he added.

     Possibly a better way is by getting the medical community involved in promoting radiation's benefits, a task that won't be easy, Pollycove conceded. Pollycove's comment came after a statement from an audience member who said that he (the audience member) probably received more radiation dose from one angiogram test performed on his heart than he got from his entire career working at a nuclear facility. "There was no indication that I was receiving any radiation whatsoever except that I was aware of it," said the audience member. "So I question if the doctors, in trying to treat their patients, are being too coy and subtle to the point where the public is unaware of the benefits they're getting from the diagnostic treatment of nuclear medicine."

     Pollycove's comment: "You're right. They run into so much opposition from anti-nukes and from the occasional patients who are frightened to death [of radiation] that they don't want to even bring up the subject."

     Tschaeche added that the reason there is no support from the medical community is that it enjoys what basically is an exemption from radiation protection requirements. "The reason why we don't have data from medical disclosures is because there is no requirement to calculate the dose," he said. "That's one of the reasons why, in the [planned] U.S. ANSI standard, we're going to see if we could put the requirement to have medical exposures included."

     Pollycove also implied that the NCRP and ICRP were looking the other way in this regard. "They don't want to touch medicine," he said, "because they say at these doses there's so little harm compared to good that they really don't need to be concerned about this."

     Muckerheide said that if it weren't for low-level waste, nuclear medicine wouldn't have a common interest with other nuclear industries. "But if you really look at radiation exposure [as performed by radiologists], you have to say that if the LNT were true, radiologists would be killing more people than anybody," he said. "And yet the linkage isn't there."

     A final few pieces of support for LNT contradiction are currently in production. The first is "Radiation Hormesis: The Scientific Foundation," which is being funded by the NRC to be published in year 2000, according to Pollycove. The report will evaluate about 500 papers on the subject of the LNT, about 10 percent of which have been termed "excellent in statistics," he said. In this research, he said, the researchers have not been able to find one statistically significant study that does not demonstrate radiation hormesis in the low-dose range — that is, 1-20 rad. In fact, he said, "every single one that is statistically significant shows a clear beneficial effect, not `no harm,' but a clear beneficial effect."

     The 'Radiation Hormesis' report will be available on the World Wide Web, he said, which will make it "hard for the kind of chicanery that's been going on" to continue. LNT supporters will have to "face the actual publication," Pollycove said. "That, I think, will be a significant step forward" for the contradiction of the LNT.

     Pollycove noted that a second work is being compiled by the International Center for Low Dose Research, which is part of the University of Ottawa, Canada. The center is evaluating radiation papers and fostering current research showing what effects low doses may have, he said. 

     Pollycove closed the session by mentioning a Canadian fluoroscopy study of 32,000 women in tuberculosis sanitariums between 1930 and 1952. By sheer coincidence, he said, each woman received a number of fluoroscopic exams, and each one was 2/10 rad, which is about the average dose in the mammogram given today. Results showed that the women who received 15 rad over two to three years had 34 percent less death from breast cancer than the women who were considered the controls, who received anywhere from 1 to 9 rad. "The 34 percent reduction was more than two standard deviations below the controls," Pollycove said. The results of the study were published in The New England Journal of Medicine, and it was peer reviewed by radiation experts. But the authors had published the data in tabular form and never plotted it out, so that their conclusion, according to Pollycove, was that "one rad equaled risk." The authors, Pollycove said, "knew that if they plotted it, anybody could look at it and see [that low doses had beneficial effects]."

     One of the authors re-released the paper in 1996, under the pretense of up-dating it, Pollycove said. In the preamble, according to Pollycove, the author stated that no low-dose data existed, so that it was necessary to use high doses and extrapolate down.  What the author did, according to Pollycove, was to eliminate the 1-9, 10-19, 20-29, and 30-49 rad categories and put them all in one category, 1-50, and then went up from there.  The author, Pollycove added, is a member of the BEIR VII committee, and the paper is one that the committee is going to use to examine the LNT. The only way the paper could show linearity, Pollycove concluded, was if some of the data had been "juggled."