Some scientists and physicians eminent in the investigation of biological effects of radiation in animals and in humans have not been the most careful in expressing the range of risks to the public—possibly because they are not astute in the language of probability, or chance. They have repeatedly made the statement that,
This sentence itself is dangerous, because it causes undue fear in the public mind of many of the known beneficial uses of radioactive materials that are essential to health and welfare (Waltar 2004). Some of these beneficial uses expose members of the public to negligible levels of radiation, if any at all. The word "dangerous" to a member of the public usually means that the threat of death from the exposure is imminent. This is obviously equivalent to a myth, because, ... we are always exposed to some radiation. In fact, the average exposure in natural radiation can vary a factor or two or more, depending in whether you live at a high or low altitude, whether you are exposed to uranium–containing building materials in your home, or whether radon emanates from the soil beneath your home and is not vented away. There are even places in the world where people live and receive ten or more times the average background in the United State of about 300 mrem per year (Eisenbud and Gesell 1997). Even our bodies are exposed to radiation from naturally radioactive materials present in our bodies, such as potassium–40, which is not removable from the potassium needed in our bodies for us to live.
Some Personal Perspectives About Risks Of High Versus Low Levels Of Radiation
Soon after the Three Mile Island (TMI) accident, I was invited to participate in a panel organized by the Pennsylvania Medical Society in conjunction with the Commonwealth of Pennsylvania, to inform physicians and the public about radiation exposures resulting from the accident. While I was waiting for my turn to speak, I was astonished to hear Dr. Arthur C. Upton, M.D., Ph.D., say during his talk that, "Any radiation is dangerous." I knew him to be an outstanding physician and researcher in radiation bioeffects, and he later became Director of the National Cancer Institute. He must have meant that even very small amounts of radiation might have some very small chances of causing cancer. Unfortunately, I have heard Dr. Upton's statement repeated many times by others since the TMI incident. More recently, a number of otherwise competent scientists I know have made similar statements. In fact, in a recent booklet of the EPA (2007) on how to communicate radiation risks, on page 16 there is the statement that, "No amount of radiation is safe." This statement is equivalent, and just as misleading and dangerous as the statement that, "Any amount of radiation is dangerous." If these statements were true, there would be no human race. As shown before, we are all exposed to some level of radiation from natural background radiation and other sources. The human race has even evovlved under exposures to natural radiation that were ten times higher many millions of years ago (Carbon 1997). What they were referring to is the linear, non–threshold (LNT) model, of radiation risk vs. dose that is used for conservatism in peacetime control of radiation exposure. Dr. Elaine Ron, one of the leading cancer epidemiologists at the National Cancer Institute, has reported that there is no evidence of non–linearity in the dose range below 15 rad from studies of the Hiroshima–Nagasaki (HN) population exposed to prompt radiation in Japan (Ron 2007). Although this conclusion is based on only 84 "excess" cancers assumed to be (but actually not) statistically significant and attributable (only with great uncertainty) to radiation out of a total of about 14,000 cancer cases due to all causes in the below 10 rad range in the HN study population of more than 100,000 persons, these are the primary data on which ICRP, NCRP, and radiation safety regulatory bodies assume that radiation risks increase from zero linearly as dose increases, ignoring other evidence that doses within a certain low range can also have beneficial effects (hormetic effects) that completely overcome net risks. In my own publications, I have used the LNT model for my own recommendations for peacetime ease of management of radiation protection programs, and to avoid the unnecessary spread of radioactive contamination that could affect other peacetime applications. However, we must not induce unfounded fears in the public mind and cause undue panic in emergency situations where radioactive materials are deliberately released by terrorists, and where doses are below (or even somewhat above) the "accepted" 25 rem for responders in life–saving situations, or where doses to members of the public are below levels likely to cause harm. There are so many greater risks from panic and improper behavior. We must not ignore the extremely low chances of health effects at low exposure levels that even the LNT model predicts. Moreover, we should remember that for such doses received over a longer period, perhaps many days, there are biological repair processes. Also, there is evidence that doses lower than about 10 to 20 rem can have beneficial (hormetic) effects through the stimulation of the immune system, and through increasing resistance to higher subsequent doses (Luckey 1991; Lenihan 1993; UNSCEAR 1994; Brodsky 1996a; Rockwell 2003; Scott et al, 2008). We know from experience that, even with the LNT model, as the dose goes down, the risk can be made to go down to negligible levels—risks far lower than those accepted by even the most cautious members of the public in their daily lives. This is true even if we ignore the evidence for hormetic effects of low levels of radiation (Brodsky 1996a; Lenihan 1993, especially pages 18–33). I can conclude only that those persons of scientific backgrounds who have stated that, "Any radiation is dangerous," have not realized the inappropriate fears that this statement would invoke, often tending to preclude the beneficial health and economic applications of nuclear energy and byproduct sources (Waltar 2004; Rockwell 2003). Such fears have also prevented us from an adequate civil or homeland defense to reduce unnecessary exposures in the event of terrorist attacks or accidents releasing radioactive materials. I do not think that Dr. Upton would make such a statement today (Mettler and Upton 1995).
High enough exposures to radiation would, of course, be dangerous. Above some level, where the mean whole body dose in a short time is above about 10 – 20 rem, as exposure (or dose) goes up, risk can go up. This is true for the LNT model or other proposed models of risk versus dose. Organizations that recommend safety guidance for radiation protection, and government agencies at present, assume for simplification of radiation protection practices that even very low exposures entail some (very low) risks. Nevertheless, even with the conservative LNT assumption, recommended and regulatory limits of exposure to workers have always been based on keeping risks down to the same risk levels, or below, of accidental injury or illness exhibited in the safest industries and work situations (Brodsky 1996). Limits of public exposure have always been kept at least one-tenth below those of workers. We discuss and deal with an enormous range of amounts of radiation exposure . . . . The word "dangerous" conveys to members of the public that they are being exposed to enough exposure to be an immediate risk to life, requiring immediate escape or protective action. The word conveys that even extremely low doses are If any radiation dose was dangerous, none of us would ever exist. As noted earlier, there have been even greater exposures of the human race to natural background radiation in earlier millennia of human existence. Even without assuming hormesis, my experience in research and regulatory agencies confirms that all beneficial technologies involving radiation exposure can be, and have been, conducted with a safety record much better than for many other human activities (Waltar 2004); this is true despite other impressions often given to the public in the news and popular literature. . . . . Even just for the natural potassium within each of our bodies for proper heart activity, a small percentage (about 0.0118 percent) of the atoms is the radioactive potassium–40 (Eisenbud and Gesell 1997). Potassium–40 is abbreviated K–40 by scientists. This small amount of natural K–40 among the natural stable K–39 in our bodies is "radioactive"; that is, the K–40 atoms slowly transform into stable calcium–40 atoms, K–40 and K–39 atoms are so similar chemically that there is no way we can get rid of the K–40 in our bodies. The transformation of K–40 is so slow that it takes 1.28 billion years (International Commission on Radiological Protection (ICRP) 1983) for half a bunch of K–40 atoms to change to stable calcium–40 (Ca–40); yet, there are so many billions of trillions of K–40 atoms in our bodies (mainly among about 140 grams of potassium in muscle tissue) that each of us has about 3700 K–40 atoms disintigrating each second. Each transformation emits beta and x radiations that are not very penetrating but contribute to about half of our self–exposure from within our bodies. (Our total self–exposure to internal naturally occurring nuclides gives us an annual dose of about 39 millirem (mrem).) In addition, about 10.7 percent of the transformations of K–40 also emit a high–energy gamma ray of 1.46 MeV energy; this gamma ray can penetrate through tissue, and only a fraction of its energy, on the average, is absorbed within our own bodies. Therefore, when I hug my wife, I am bombarding her with some hundreds of high–energy gamma rays each second — those gamma rays that are emitted in her direction and are not absorbed in my body. However, when I hug her, she is doing about the same thing to me. Anyway, the enormous benefit of her healthy hugs is trillions of times greater than any insignificant risk I might receive from the small exposure or dose of absorbing hundreds of gamma rays each second. I hope that my wife feels the same way. I hope that this incontrovertible fact will help indicate how absurd it is to say that, "Any radiation is dangerous." When I was on the faculty of the University of Pittsburgh, I served in 1964–1970 as Technical Director of Radiation Medicine at the Presbyterian–University Hospital. Pittsburgh, I served in 1964–1970 as Technical Director of Radiation Medicine at the Presbyterian–University Hospital. At this hospital, I designed with my colleagues Dr. F.J. Bradley and Dr. Neil Wald, and set up, a large shielded counting room and radiochemical laboratory for measuring amounts of radioactive material in patients and workers from the nuclear industry. To calibrate my measurements, I actually used the amount of K–40 in my own body to adjust and calibrate a large scintillation counter for detecting gamma radiation "fingerprints" from radioactive materials in the bodies of workers exposed to inadvertant inhalation of radioactive materials. I also filled a human–like plastic phantom with water and added the 140 milligrams of potassium to provide another check on the gamma ray counts. Because at the time I was about the size of an average man, my gamma ray counts and the shapes of my 1.46 MeV energy fingerprints matched those of the phantom exactly. Thus, I also effectively measured the K–40 in my own body in this way, in comparison to the phantom. This is one way in which muscle to fat ratios are measured in humans. The gamma ray counters that I used were within a large room with walls made of pre–atomic–bomb steel about 6 inches thick, so that other background gamma radiation interference with our counts was about a factor of 50 lower than the average background exposure you receive from gamma radiation every day. Many thousands of gamma ray counts were detected from my body every minute by the large scintillating crystal about two feet above my body when I reclined in a specially–selected low–activity, lawn–type chair within the steel room. I often used 40–minute counts of my body reclining in the lawn chair as a check on system reliability. (This was a good way to work when I was tired.) In addition to the exposure from K–40 within our bodies, there are varying amounts of K–40 in rocks and soil in our environment; gamma rays from the ubiquitous K–40 in our environment contribute radiation exposure from sources external to our bodies. There are also many other naturally occurring radioactive nuclides (radioactive atoms) in our environment. Of about 340 natural types of atoms, about 70 are radioactive (Eisenbud and Gesell 1997, page 134). By just living, we receive certain "background" exposures from these natural radionuclides.
- In the air, gamma rays are primary from fallout to people.
- Much of the gamma rays in the surrounding air, from covering the ground uniformly, bounce off electrons in the air close to your shelter, causing a scattering of this energy, gamma radiation, down to persons in the shelter!
- This scattering of gamma radiation can be intensified by any dense materials that are above ground near your shelter, and serve to reflect this radiation—known as secondary scattering of gamma rays, down into your shelter.
- Therefore, you need 12–inches, minimum, of concrete below ground level to protect you from scattering radiation of gamma rays. Or...better to have two feet of concrete, or 3 feet of dirt can be used to have good protection from gamma radiation. 'This is equivalent,' according to Dr. Brodsky, 'to providing about 300 pounds of dense building material behind each square foot of wall or ceiling surface'. This would give you protection during the 'Decay' time."
- 100 R/hr @ 1 A.M. Note: If five hours after the explosion all of the material that is going to fall on your locale has already fallen and a dose rate of 100 R/hr is measured at five hours, then this is your starting point. You log this and the time again on your data sheet, then ....
- Five hours later from the announcement, which is considered the first five hours; then, it is 10 hours later, which is twice the time! Remember this. Then, we take 100 R/hr divided by 2 = 50 R/hr. That means that after ten hours (twice the time), the radiation intensity has fallen from 100 R/hr to 50 R/hr. Write this down on your data sheet with the time.
- A third five hours later thrice the time, which is 15 hours of time that has gone by, still more decay is occurring. Then, 100 R/hr divided by 3 = 33.33 R/hr. Once again, log this information with the time on your log or data sheet.
- You feel good about this, because you can see the radiation intensity is going down! So, another 5 hours has gone by quadruple the time; this means you must watch the time; then, log the following for the fourth entry: 100 R/hr divided by 4 = 25 R/hr.
- Continue staying in your shelter and keep doing the above for every 5 hours until, you reach from Table 1.1: 0 to 50 R/hr; generally considered safe. However, I suggest you do not go out of the shelter unless for a few minutes for emergency repairs to reinforce your shelter, get water, etc. When you log 'Less than 0.5, 'No special precautions are necessary for operating activities. Keep fallout from contaminating people. Sleep in the shelter. Always avoid unnecessary exposure to radiation.' After two or three weeks, fallout should be two times less than natural background radiation. This demands you have prepared by knowing what the outside background radiation is around your shelter; and, what it is in your shelter!
"Monsieur Kong, As we have discussed many times in the past, 'Fire will fall from the heavens and mingle with fire from the Earth'. The fire from the Earth are the volcanoes revevving up all over the world and now increasing ever the more so. Their gasses are very toxic; this is why in my private lectures, and on the treks we have made, I said to have a gas mask outfitted with oxygen; carrying oxygen bottles with you also, and have Carbon Monoxide detectors pinned to your person and wherever you run...and in your shelter. When the indicators do a color change, go for the mask!" These fires also include the fires that will come from thermonuclear attacks on American soil.