The Fallout Chronicles IX - Is There a Threshold?
The Fallout Chronicles IX - Is there a threshold?
In 1990, the year the Radiation Exposure Compensation Act was signed by President George H. W. Bush, a scientist named John F. Gofman (1918-2007) published a study entitled Radiation-Induced Cancer from Low-Dose Exposure: An Independent Analysis.
Gofman was an M.D. and Ph.D. in Chemistry who had spent many years as a professor at the University of California at Berkeley. In the early 1960’s he had been asked by the AEC to establish and direct the Biomedical Research Division that was being set up at Lawrence Livermore Laboratory to study the health effects of the many different '“nuclear activities.” The AEC had been inspired to do this, it seems, by the findings emerging about their unforthcoming (to put it mildly) response to problems caused by fallout from the detonations at the Nevada Test Site.
After his appointment as the first director of the AEC’s Biomedical Research Division, Gofman came to feel that the AEC was continuing to suppress his and others’ findings. He left the directorship and the division in 1963.
Gofman’s book is subtitled An Independent Analysis and the subtitle is not window dressing. Gofman, who by now was retired, had come to feel that the findings of what he calls “the radiation community” were usually tainted by conflict of interest. He defines the “radiation community” as “all the industries, professions, and governments engaged in activities which CAUSE exposure to ionizing radiation, plus the individuals who regard their jobs, their research grants, or their personal advancement as dependent on such sources.”
More specifically,
The leading members of the radiation community are (A) governments—which sponsor civilian and/or military uses of nuclear energy, and sponsor the overwhelming share of all research on radiation’s health-hazards—plus (B) the nuclear electric industry and (C) the professions of nuclear medicine and radiology.
Gofman had come to see the findings of “the radiation community” as exemplifying the principle, “Be careful not to learn what you don’t want to know.” Let us acknowledge that this principle may apply to some of us in the public too. Maybe particularly when it comes to nuclear weapons.
Gofman takes issue in this book with a report released in early 1988 by the “radiation committee” of the United Nations, UNSCEAR (the United Nations Scientific Committee on the Effects of Atomic Radiation) and another in 1989 by the “radiation committee” of the National Research Council’s Committee on the Biological Effects of Ionizing Radiation (BEIR-5).
Gofman’s principal source for the data he analyzed is the Atom Bomb Study, a study that was begun in 1950 by the Atomic Bomb Casualty Commission of 91,231 survivors of the atomic bombing of Japan. (Gofman objects strongly to alterations of the Study’s data base that seem to him to have been designed to justify more benign conclusions about the effects of low-level ionizing radiation.)
His study arrives at “risk-estimates that are up to 30-fold higher than the wide range of values provided by UNSCEAR and BEIR.”
Gofman’s final conclusions are straightforward and striking.
A careful analysis of the human data from this study, Gofman says, proves, not just that the levels for “safe” low-level ionizing radiation set by the UNSCEAR and BEIR reports were far too high, but that there is NO safe dose or dose rate of ionizing radiation.
His study also shows, he says, that low doses are more, not less, likely to cause cancer than are higher doses. Finally, it shows also that the duration of their carcinogenic activity is lifelong.
The study gives us reason to think, he says, that “low dose ionizing radiation may turn out to be the MOST important [emphasis in Gofman] single carcinogen to which huge numbers of humans are actually exposed.”
Have “huge numbers of humans” been exposed to low-dose radiation from fallout?
The Centers for Disease Control says we have been.
Radioactive fallout was deposited all over the world, so many people were exposed to it. Even today, radioactive fallout is present in all parts of the world in small amounts. CDC [Centers for Disease Control] and NCI [National Cancer Institute], in their study of global fallout, looked only at fallout in the contiguous United States (the 48 states between Canada and Mexico). The study found that any person living in the contiguous United States since 1951 has been exposed to some radioactive fallout, and all of a person’s organs and tissues have received some exposure.
Some have tried to counter Gofman’s findings by drawing our attention to the natural background radiation we earthlings are always and inescapably experiencing. His reply is simple: background radiation1 may be inescapable but it also isn’t “safe.” It too is a cause of cancer.
Next: Where does all this leave us?
For those who might want to know, here are the ingredients of low-level natural background radiation as set out by the National Research Council, in Health Risks from Exposure to Low Levels of Ionizing Radiation: BEIR VII Phase 2. The National Research Council is a member of what Gofman calls “the radiation community.”
[LET=linear energy transfer, a measure of the effect of ionizing radiation on, say, human flesh. mSV=milliseivert, a measure of the level of energy of radiation]
“Human beings are exposed to natural background radiation every day from the ground, building materials, air, food, the universe, and even elements in their own bodies. In the United States, the majority of exposure to background ionizing radiation comes from exposure to radon gas and its decay products. Radon is a colorless, odorless gas that emanates from the earth and, along with its decay products, emits a mixture of high- and low-LET radiation. Radon can be hazardous when accumulated in underground areas such as poorly ventilated basements. The National Research Council 1999 report, Health Effects of Exposure to Radon (BEIR VI), reported on the health effects of radon, and therefore those health effects are not discussed in this report. Average annual exposures worldwide to natural radiation sources (both high and low LET) would generally be expected to be in the range of 1–10 mSv, with 2.4 mSv being the present estimate of the central value. Of this amount, about one-half (1.2 mSv per year) comes from radon and its decay products. Average annual background exposures in the United States are slightly higher (3.0 mSv) due in part to higher average radon levels. After radon, the next highest percentage of natural ionizing radiation exposure comes from cosmic rays, followed by terrestrial sources, and “internal” emissions. Cosmic rays are particles that travel through the universe. The Sun is a source of some of these particles. Other particles come from exploding stars called supernovas.
“The amount of terrestrial radiation from rocks and soils varies geographically. Much of this variation is due to differences in radon levels. “Internal” emissions come from radioactive isotopes in food and water and from the human body itself. Exposures from eating and drinking are due in part to the uranium and thorium series of radioisotopes present in food and drinking water. An example of a radioisotope moving through the food chain would be carbon-14 (14C), a substance found in all living things. 14C is created when cosmic rays collide with nitrogen atoms. 14C combines with oxygen to create carbon dioxide gas. Plants absorb carbon dioxide during photosynthesis, and animals feed on those plants. In these ways, 14C accumulates in the food chain and contributes to the internal background dose from ionizing radiation.
“…The total average annual population exposure worldwide due to low-LET radiation would generally be expected to be in the range of 0.2–1.0 mSv, with 0.9 mSv being the present estimate of the central value.
“…A 1987 study of ionizing radiation exposure of the population of the United States estimated that natural background radiation comprised 82% of the annual U.S. population exposure, while manmade sources contributed 18% ….
…[Here are our estimates of ] the relative contributions of the various types of man-made radiation to the U.S. population. Medical X-rays and nuclear medicine account for about 79% of the man-made radiation exposure in the United States. Elements in consumer products, such as tobacco, the domestic water supply, building materials, and to a lesser extent, smoke detectors, televisions, and computer screens, account for another 16%. Occupational exposures, fallout, and the nuclear fuel cycle comprise less than 5% of the man-made component and less than 1% of the combined background and man-made component. Additional small amounts of exposure from background and man-made radiation come from activities such as traveling by jet aircraft (cosmic radiation—add 0.01 mSv for each 1000 miles traveled), living near a coal-fired power plant (plant emissions—add 0.0003 mSv), being near X-ray luggage inspection scanners (add 0.00002 mSv), or living within 50 miles of a nuclear power plant (add 0.00009 mSv).”