China & India

"In China, a meticulous study measured the radon level for 1 year in the houses of several hundred women with lung cancers and in homes of a similar number of healthy women. The results demonstrated at a 95% confidence level that women who lived in high-level radon houses (more than 350 Bq/m^3) had an 80% lower lung cancer risk than those living in low-level radon houses (4 to 70 Bq/m^3). For perspective, the EPA considers that remedial action at any level down to 70 Bq/m^3 would be cost effective, even for the cost of reducing the level from 150 to 70 Bq/m^3 at about $2 million per hypothetical life saved. (Schiager 1992)." [Blot, W.J., et al. Indoor radon and lung cancer in China. Journal of the National Cancer Institute, 82, 1025, 1990.]

"While the poorly fed coastal population in Kerala, India, receives 400% - 800% more background radiation than neighboring areas, the people have a higher fertility rate with the fewest neonatal deaths of any other Indian state." [Auxier, J.A., Reactions to BRC. Health Physics Society Newsletter, 16, 5, 1988.]

India

Indian researchers K.S.V. Nambi and S.D. Soman collected an analyzed cancer mortality data from a number of state hospitals along with the average background radiation in each locality. (Hospitals in Delhi, Kerala, Maharashtra, Pondi and Tamil Nadu were excluded as they are regional centers that take patients from several states.) A plot of these data, shown in Figure 23, show an unmistakable negative correlation between background radiation and overall cancer mortality. In an extended study, the investigators found a significant inverse relationship (the more radiation, the less cancer) between background radiation and all types of female cancers except those of the mouth and cervix. [Nambi, K.S.V., and Soman, S.D. Further observations on environmental radiation and cancer in India. Submitted to Health Physics, 1990.]

Source for Figure 23 Cancer Mortality vs. Background Radiation (India) Nambi, K.S.V. and Soman, S.D. Environmental radiation and cancer in India. Health Physics, 52, 653, 1987.

"Why Don't They Evacuate Norway?"

"Why don't they evacuate Norway?" - a question by UN Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) Member Dr. Zbigniew Jaworowski in noting that the limits set for evacuating people from around Chernobyl were below the average background radiation in Norway, and far, far below the high background areas of Norway and many other places in the world.

On a planet where virtually nothing is distributed equally, we should be surprised if terrestrial sources of background radiation were somehow evenly allocated. And they are definitely not. As noted in Table 10 (in chapter 11), some places have more than 130 times the average background radiation of the United States, and since the U.S. average is considerably higher than the ambient radiation inn other locations, there is easily a factor of 150 difference between points on the earth.

Believers in the Linear No-Threshold (LNT) hypothesis tell us that all radiation is dangerous, and that the danger is proportional to the dose received. Hey, since we have all these different levels of background radiation across the globe, all they have to do to prove their theory is to demonstrate that as the background radiation increases, so does cancer incidence - and perhaps even other maladies that we haven't yet even considered might be caused or aggravated by additional exposure.

Sadly (for them), this is demonstrably untrue. More than that. There is a large body of evidence that points in the opposite direction - that we are "underexposed" and that exposure to additional radiation will increase our health and vitality. This chapter intends to show some of that evidence.

Very Strange - But I Don't Make the Data; I Just Report Them

The next figure is about mice that were not subjected to radiation but who had fathers that had been exposed prior to becoming a mouse-parent. (Yes, I realize this may be sounding a little like Psychic Hotline.) Figure 12 shows the life span of unexposed mice who were fathered by mice (naturally) that had received 30, 70, 100 or 150 cGy of X-rays at sixteen weeks of age. (Irradiating the mother mice had no effect on the life span of their progeny.)

Caption for Figure 12: Life Span of Mice Whose Sires Were Irradiated Spaulding, J.F., Brooks, M., and McWilliams, P. Some effects of X irradiation in successive generations on an inbred and hybred [sic] population of mice. Genetics, 50(Suppl.), 1179, 1964. Also in Effects of ionizing radiation in reproduction, Carlson, W.D. and Gassner, R.X., eds., Pergamon Press, London, 1963.

How do I explain such a phenomenon? I haven't the foggiest idea... and I don't think anyone else does either. But if there were a possibility I could add 20% - 40% to the life span of my child by exposing myself to 100 cGy of radiation, that wouldn't be much of a decision. It is questions like these that we should be setting the stage for future generations to answer. Instead we are planning how to waste some $1 trillion cleaning up "nuclear dumps" that are less radioactive than the natural soil in many parts of our world.

You're probably tiring of mousy data, and I said we'd get on to humans after a couple more reports on rodent experiments. We'll just breeze right through these and let you practice your mental conversion from cGys to rads or cSvs to mrems (they are all the same for the radiation in all these citations).

• "The effect of neutron exposure [3.2 cGy-6.3 cGy] upon the combined sexes showed low doses decreased the natural incidence of all tumors." (emphasis added) [Meweissen, D.J. and Rust, J.H. Reticuloendotheial neoplasms in C57 black mice after fast neutron irradiation at low doses. US Atomic Energy Commission Conference 740930, Oak Ridge, 1976.]
• Mice exposed to 150,000 mrem at five and twelve days following infection with "friend [sic] virus" recovered while all of the controls died within forty days. [Shen, R.N., Hornback, N.D., Lu, I., Chan, L.T., Drahms, Z., and Droxmeyer, H.E., Low dose total body irradiation; a potent antiviral agent in vivo. International Journal of Radiation Oncology and Biological Physics, 10, 185, 1989.]
• "[Studies on mice] in the dose range 0-3 Gy by two independent research groups at Oak Ridge and at Casaccio near Rome leads, for gamma radiation and X-rays, to a statistically significant decrease of the cancer rate at low doses and therefore to biphasic relationships for tumors of the reticular tissue, for several solid tumors, as well as for cancer as a whole." (emphasis in the original) [Weber, K. Biphasic dose-effect relationships in experimental studies of radiation cancer in animals. [English summary.] Strahlenbiologie und Strahlenshutz, Hannover. October 1996. IRPA, Progress in Radiation Protection.]
• "Male mice exposed to acute doses of 2 Gy for 82 successive generations showed no abnormal offspring; this acute dose is equivalent to 50 times background radiation for humans from the time of the Roman Empire to present." [Spaulding, J.F., Brooks, M., and McWilliams, P. Some effects of X irradiation in successive generations on an inbred and hybred [sic] population of mice. Genetics, 50(Suppl.), 1179, 1964. Also in Effects of ionizing radiation in reproduction, Carlson, W.D. and Gassner, R.X., eds., Pergamon Press, London, 1963.]
• "Urinary testosterone of chronically irradiated mice, 5,000 to 10,000 mrem of X-rays per day, was increased 264% above controls." (Look out, Viagra.) [Liu, S.Z. Effects of low dose ionizing radiation on defense and adaptive mechanisms. Conference on High Background Area Research, Taishan, Nov 1988; China Medical Journal, 102, 750, 1989.]
• Of the offspring of 124 male mice exposed to 276,000 mrem of X-rays and 124 control mice, 20 of 3,990 pumps from exposed males were stillborn, as compared to 45 of 3,418 control pups. [Luning, K. Studies of irradiated mouse populations. Hereditas, 46m 668, 1960.]
• In an experiment involving 3,505 autopsied mice with acute exposures of 18 cGy or more, the age-specific lymphocytic lymphoma rate was 16% of controls for 36 cGy exposures and 3% for those exposed to 18 cGy. [Meweissen, D.J., Rust, J.H., Harem, J., and Clement, M.J. Assessment of dose-response relationships in carcinogenesis following low radiation dosage. In Late effects of ionizing radiation. International Atomic Energy Agency, Vienna, 1978, 291.]
• Radio-resistance - the resistance to high levels of radiation exposure - in mice was enhanced by previous exposure to lower levels of X-rays. Survival of mice exposed to 700,000 mrem increased from 10% in the control group to 25%, 50%, and 82% for exposures to 120,000 mrem at one, two and three weeks of age, respectively. [Kochanski, W., et al. Immunologic analysis of the condition of increased resistance of organisms exposed to ionizing radiation. Medical Radiology, (Moscow) 1, 43, 1956. (Hmm, why would they have been interested in such a subject?)]
• Mice that had been exposed - from weaning through breeding - to 1 cGy/day had shorter generation times and higher birth rates that unexposed controls. (A later experiment on "deer mice" by the same researchers gave similar results.) [French, N.R. and Kaaz, H.W. The intrinsic rate of increase of irradiated Peromyscus in the laboratory. Ecology, 49, 1172, 1968.]
• "For newborn mice exposed to 180 rad at 0.07 R/day, the life span was significantly longer than it was for controls. At all dose levels the 2-month age group lived significantly longer than did the median controls." [Patterson, H. Wade, editor of the Health Physics Journal, elucidating experimental data by Spalding, J.F., Thomas, R.G., and Tiejen, G.L. in Life Span of C57 Mice as Influenced by Radiation Dose, Dose Rate and Age at Exposure, Report No. UC-48; LA-9528, Los Alamos National Laboratory, 1982.]
• "Male AKR mice were irradiated with 5 cGy three times a week or 15 cGy two times a week for 11 weeks from age 40 weeks. The incidence of thymic lymphoma was 80.6% in sham-irradiated mice [controls], 67.5% in mice irradiated with 5 cGy three times a week, and 48.6% in mice irradiated with 15 cGy twice a week." [Ishii, K. and Watanabe, M. Participation of gap-junctional cell communication on the adaptive response in human-cells induced by low-dose of X-rays. International Journal of Radiation Biology, Vol. 69, Issue 3, 1996.]

***

Gee, I could go on about mice for hours... unfortunately I wouldn't have any readers. So let's move on to the evidence that alerted so many people to the truth of Dr. Luckey's claim of radiation hormesis: the Japanese survivors and their stubborn refusal to die on the LNT schedule.

Growth Rate of Irradiated Mice

In a 1954 study by E. Lorenz et al. on the "effects of long-continued total body gamma irradiation on mice, guinea pigs, and rabbits," it was found that the growth rate of mice increased in proportion to the exposure, up to the level of 1.0 cGy (1,000 mrad) per day. [Lorenz, Egon, et al. Effects of long-continued total body gamma irradiation on mice, Guinea pigs and rabbits, in Biological Effects of External X and Gamma Radiation, Vol. 1, Zirkle, R. E., ed., McGraw-Hill, New York, 1954.]

Above this point, as shown in Figure 6, the growth rate decreased, until it was the same as the control group at approximately 7.5 cGy per day. Irradiation, which lasted eight hours per day, commenced one month after birth and continued until death. This study did not, however, examine the question of the relative longevity of the mice involved - a subject taken up later in this chapter.

[Caption for Figure 6: Growth Rate of Irradiated Mice - Note: "Control" or "Controls" refers to a group of unexposed animals often as large as the entire exposed cohort. The average behavior of this group is the norm to which all other groups are compared. Source: Lorenz, E., Jacobson, L.O., Heston, W.E., Shimkkin, M., Eschenbrenner, A.B., Deringer, M.K., Doniger, J., and Schweistal, R., Effects of long-continued total body gamma irradiation on mice, Guinea pigs, and rabbits. III. Effects on life span, weight, blood pressure and carcinogenesis and role of intensity of radiation. In Biological Effects of External X and Gamma Radiation, Vol. 1, Zirkle, R. E., ed., McGraw-Hill, New York, 1954.]

The size advantage (considered "healthy" in mice, though probably not popular in Minnie's ballerina class) continued into late maturity - about 100 weeks.

If we consider the background level to be the U.S. average of 0.3 cSv or 300 mrem per year (about 1 mrem per day) [the dose, expressed in units of energy per mass, is independent of the size of the recipient], then the fastest-growing rodents received about 1,000 times their normal background radiation - hardly in keeping with the LNT - which would predict unhealthiness at any level above background. It strongly suggests beneficial radiation effects are at work.

Home Is Where the Radiation Is

Table 11 – Chernobyl Cs 137 Burden in Various Areas vs. Natural Background
Location	Range (Bq/m^2)
European Cs 137 contamination outside former USSR	20,000 to 23,000
Cs 137 contamination inside former USSR	40,000 to 5,000,000
Natural radionuclides in soil of above areas	177,000 to 6,500,000
Source: Table 2 in 1997 statement by U.N. Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) member Zbigniew Jaworowski

From Table 11, radon is apparently the dominant source of background radiation. As pointed out earlier, it has not always been considered to be such, as residential radon seems not to have existed until December 1984, when a nuclear worker set off radiation alarms on his way into the Pennsylvania Limerick power plant. A subsequent investigation showed that the residential radon level in the Reading Prong area of Pennsylvania and New Jersey exceeded the level found in many mines. Always quick with a horror story, the EPA "found" this new "danger" to millions of citizens and gleefully reported that as many as 20,000 lung cancer deaths in the United States are caused by residential radon. Perhaps someone at the EPA should have been reading a certain $36 per year newsletter.

Petr Beckmann was well aware of this noble gas situation, as evidenced by 106 different mentions of radon in his newsletter Access to Energy from September 1979 through June 1992. [Now edited by Dr. Arthur Robinson, President and Research Professor, Oregon Institute of Science and Medicine, Box 1250, Cave Junction, OR 97523. Back issues, twenty-one-year CD-ROM, and index available.]

Professor Beckmann was wise enough not to condemn the radon levels out of hand, but he took the bureaucrats to task for their double standard: One hand of government was tightening industrial radioactive emission standards to ridiculously low levels, while the other hand was encouraging/demanding that homeowners modify their homes to the point where radon doses to the average citizen were hundreds - if not thousands - of times greater than the levels dictated to nuclear workers. Here is an example from the November 1983 edition of his newsletter - prior to the EPA's "discovery" of residential radon:

"Although radon exposures of the public are regularly hundreds and even thousands of times higher than from nuclear power operations, that alone may not be cause for alarm. Our purpose here is not to scare readers with the dangers of radon, but to point out the inconsistency of the media and of the politicians bent on pleasing them."

When it came to radon, one might ask about the government's myopia for so many years. Well, one might also remember that during this period we were having one of our regularly scheduled energy crises and were being urged to seal up our residences and commercial buildings. (Anyone born before 1960 should surely remember Carter's "thermostat cops.") Without ventilation, the heavy gas, almost eight times heavier than air, seeps into basements or lower floors with additional amounts coming from unvented or poorly vented natural-gas heaters. There appears to have been a contest between which "crisis" was more important - energy or radiation. Energy shortage was first out of the gate, but it's radiation coming down the homestretch.

Breaking News!! EPA Restricts Foreign Travel Because of Dangerous Radiation Levels

[Well, not yet really... but give them a little.]

The highest background radiation levels I could find are in China, India, Brazil, and Iran (more on this in chapter 17). All these countries have deposits of monazite - a black sand often found on beaches and in rare earth deposits - in which the principle radioisotopes are from the decay of thorium 232 and radium 226.

The 80,000 people of Kerala, India, receive up to 1,300 mrem (1.3 cSv or about three-and-a-half times our background exposure) per year and have been recognized for their healthfulness compared with neighboring states. The 10,000 citizens of Guarapari, Brazil, and the vacationers that flock to their beaches to bury themselves in the black sand absorb 0.03 mGy (3mrem) per hour - the equivalent of 26,280 mrem (2.6 cSv or about eighty-seven times our background) per year. [It is illegal to take the sand, but it has been done for centuries by tourists who have heard of its benefits and keep it under their beds. By so doing they receive little additional "through skin" radiation, but are exposed to continuing sources of breathable radon.]

Meanwhile in Ramsari, Iran, the 2,000 inhabitants and their ancestors have lived for centuries begin exposed up to 48,000 mrem (48 cSv or 132 times the U.S. average) and "survived" to tell about it... in fact they keep on surviving to the point that our regulators are wearing out their fingernails from scratching their LNT - and collective dose - heads. (Actually, they just engage in politically correct science: ignore those data that are inconvenient.)

Table 10 – Background Radiation in Various Locations with Comparisons
Case/Place	cGy/yr	mrem/year	Ratio to U.S. average
EPA level of concern	0.001	1	0.003
Limit nearby nuclear power plant	0.005	5	0.016
Proposed EPA maximum (all sources)	0.100	100	.3
U.S. average background	0.300	300	1.0
Chernobyl forced resettlement**	0.500	500	1.7
Colorado plateau	0.600	600	2.0
Kerala, India	1.3	1,300	4.3
Gerais, Brazil	2.3	2,300	7.7
Hormesis optimum (Luckey)	10.0	10,000	33.3
Guarapari Beach, Brazil	26.3	26,300	87.6
Ramasari, Iran (average)	48.0	48,000	132
* Adapted from “Radiation Hormesis for Health” by T.D. Luckey, Health Physics Newsletter, June 1995.
** In areas where the natural background plus the Chernobyl contribution exceeded this limit, 200,000 people were forcibly resettled.

Hormesis Mechanisms

Every second the average person in the United States is "hit" by 15,000 particles of ionizing radiation, mostly from background sources. (The 1,500 "hits" mentioned earlier were only from cosmic sources.) Why does a relatively small increase in this exposure have a positive effect on the health of individuals? That physiological changes occur is unquestionable: it has been known for almost a century that low doses of radiation increase the production of lymphocytes (white blood cells). Other changes observed to occur are:

• Increased number of immune system helper T cells
• Decreased number of immune system suppressor T cells
• Increased activity of the p53 protein [a protein that reputedly decreases the incidence of many cancers]
• Increased free-radical scavenger activity (while radiation causes the creation of free radicals, it simultaneously produces much more of the remedy than of the problem).

The above, among others, are considered to be part of the cell's defensive system against chemical and radiation insults. Interestingly, high doses of radiation have a "reverse effect" on these very same cellular activities.

In the previous quotation from Dr. Rockwell, it was noted that a poor job in the cellular repair and removal business is what causes us potentially fatal problems. The body just doesn't do well with a bunch of sick, dying or dead cells hanging around. An interesting discovery resulting from the hormesis research led by Dr. Sohei Kondo was that low-dose radiation increased apoptosis - often referred to as altruistic cell suicide. [Dr. Kondo is professor emeritus of biology at Osaka University, and senior researcher at the Atomic Energy Research Institute, Kinki University, Osaka, Japan.]

By the process of apoptosis, damaged cells were absorbed without necrosis (a fancy scientific way of saying the cellular bodies were carted off before becoming offensive) and, at the same time, healthy cell replacement was stimulated.

In considering what hormesis is, we should also be aware of what it isn't. It is not the action of radiation on a single isolated cell. In experiments involving single cells in vitro [literally, "in glass," although almost all "glass" dishes these days are actually plastic], they behave as the LNT theorists would predict: the more radiation, the less vitality. [Critics of hormesis often point out isolated cell experiments as proof against the phenomenon.]

But when a society of cells, such as those making up an organ or an organism, is subjected to a relatively low dose of ionizing radiation, protective action (homeostasis) occurs, and the effect can be quite dramatic, as will be shown in the chapters on evidence.

One final analogy: we are aware that introducing the cowpox virus into our body causes the immune system to gear up and produce antibodies that also happen to be effective against smallpox. What isn't commonly known, however, is that inoculation against one disease increases the body's resistance to others. A 1986 English study showed a decrease in death from malignant disease for all who were inoculated, as children, for any one of eight diseases. Children inoculated against measles, for example, had a better chance to survive diphtheria or whooping cough, even while lacking those specific inoculations.

Similarly, low doses of radiation "inoculate" the body to the negative effects of future high doses - while at the same time appear to have positive effects in increasing general immune competency. Those who would like to learn more about radiobiological and hormetic effects should find the references in chapter 15 to be interesting. They allude to the Japanese research on the subject, which is well ahead of that being done in the United States.

Types of Ionizing Radiation

There is no amount of radiation that is safe. - Anti-nuclear activist Dr. John Gofman

When a radioactive isotope decays, it emits one or more of three forms of ionizing radiation: alpha particles, beta particles or gamma rays. One problem in discussing the effects of radiation is the lack of understanding of these different types and how they affect the body.

Alpha-particles are actually helium nuclei, which can be seen from the periodic table to have an atomic number of two and an atomic weight of four. [In alpha-decay, the radioactive isotope is changed to the isotope of an element with an atomic number two less and an atomic weight four less than the original element.]

In the subatomic world, the emission of an alpha-particle is like shooting shot put with a sling shot: there is a lot of mass involved, but it doesn't travel very far. This particle gives up its considerable energy in one-half to two inches of air. It can't penetrate the skin and, consequently, isn't dangerous when outside the body. Because of its mass, however, it is considered to be quite dangerous when inside the body - particularly when inhaled, where it may remain in the lungs in close proximity to lung tissue cells for extended periods. [It is common knowledge that plutonium, an alpha emitter, is deadly when inhaled. You will see in chapter 16 that common knowledge may be terribly mistaken.] Fortunately, there are some very good data on this subject that we'll look into.

Beta-particles are high energy electrons that can penetrate up to three feet of air, or the first layer of skin cells, and can cause a burn not unlike that from falling asleep in the tanning bed. Beta-burns were a particular problem for workers after the Chernobyl chemical explosion and for technicians involved in some phases of the weapons-testing program in Nevada. With a mass some 1/7344 that of an alpha-particle, its energy is derived from its speed, which can approach 99.8% of the speed of light. Relatively speaking, beta "rays" are not considered much of a threat to human health although there can be complications arising from beta-burns.

A third possible product from the decay of a radionuclide (a fancy word for a radioactive isotope) is gamma radiation, which is considered to be the greatest danger from nuclear decay. It is very similar - in fact in some cases identical - to X-rays and can penetrate several feet of concrete or inches of steel. Like any other electromagnetic radiation, its intensity falls off as the square of the distance from the source. For instance, the exposure at 100 yards is 1/900 that at 10 feet; at a quarter mile, the radiation is reduced by a factor of 17,424 compared with the 10-foot value. [Luckey mentions another form of radiation, delta rays, with low energies and penetrating power, but - because of their abundance and proximity to cell structures - are important in radiobiology. See Radiation Hormesis, page 2.]

There are other forms of radiation that should be mentioned even though they are not the normal products of natural decay. The first is cosmic radiation. It consists of various types of particles, sub-particles, and high-energy photons arriving on Earth from every direction in the cosmos. Cosmic radiation, with both solar and galactic components, can have unbelievably high energies, but, fortunately, it poses no danger, since there is so little of it. For instance, protons that originated in far-off galaxies four billion years ago have energies 100 million times greater than can be created in our most advanced particle accelerators. But only about one of these per year is detected by the Akeno Giant Air Shower Array located just west of Tokyo. [Energies are in the range of 3x1020 electron-volts. For more information see Scientific American, January 1999, page 32.]

These cosmic sources make up less than 10% of the background radiation that the average U.S. citizen receives, yet we still receive about 1,500 cosmic "hits" per second, each of which - because of the penetrating nature of all high-energy particles - collides with about 10,000 of the hundred-trillion cells in the adult human body. That's 15 million "cellular events" per second. If the quotation from Dr. Gofman at the beginning of this chapter is accurate, then we are indeed in a heap of trouble.

It is, by the way, the action of cosmogenic (a fancy scientific word for "from outer space) neutrons on atoms of atmospheric nitrogen that produces the carbon 14 used for radiometric dating. [Carbon 14 dating, developed in 1947 by W.F. Libby, is based on the fact that 14C is continually produced by cosmic rays. When the high-energy ray collides with atoms in the atmosphere, free neutrons are produced which, when absorbed by a nitrogen (14N) atom, cause it to eject a proton, thus converting it to 14C. This radioisotope is taken in by plants and animals while they are alive but remains constant after death. By measuring the 14C in comparison with its decay products, the approximate age of the fossil can be determined.]

Other neutron sources - accelerators, nuclear reactors, and bombs - have great potential for danger, as the lack of charge on the neutron allows it to penetrate some eight to ten feet of packed earth - about 50% farther than gamma radiation. Strictly speaking, neutrons are not ionizing radiation, since they have no electrical charge with which to influence the electrical affinity between protons and electrons. But they can smack into light-weight atoms such as hydrogen and cause them to become ionizing projectiles.

Finally, we have X-rays, which are typically produced when an energetic electron is stopped in its tracks. Just as with gamma rays, these can travel long distances and have the potential for doing harm to the body. During the past several decades, the energy - and therefore potential harm - of diagnostic X-rays has greatly decreased because of the increased sensitivity of the film and the detectors being used. Similarly, therapeutic X-ray equipment is designed to focus energy on smaller areas with less effect on healthy tissue. Sadly, an unwarranted fear of radiation causes many people who could be benefited by the use of X-ray diagnosis and therapy to shun such treatment - and thereby become subjected to unnecessary real dangers.

A similar situation is found in the commercial/industrial environment where X-rays are subjected to such overprotective rules that their primary benefit - being able to detect flaws in welds and other material in order to protect human life - is rendered uneconomical. (No doubt there is also reluctance on the part of workers - who are victims of LNT theory fears - to use the equipment.)

All of the above forms of radiation are termed ionizing radiation because they have the ability to strip electrons from their orbits around nuclei, making the lone electron a negative ion and the "left-behind" proton a positive ion. Table 3 shows the electromagnetic spectrum illustrating the various kinds of ionizing and non-ionizing radiation. For all practical purposes, ultra-violet radiation is not ionizing, and it is the action of ionization that defines the beginning of the X-ray portion of the electro-magnetic spectrum. [While UV radiation cannot ionize an atom, it can dissociate a molecule. For example, cosmic UV can smack into an O2 molecule splitting it into two atomic oxygen atoms - which are very chemically active.]

Table 3 - The Electromagnetic Spectrum
Non-ionizing

• Radio waves (AM) - long wavelength ~100 meters*
• Shortwave radio - low frequence ~1 million Hz
• Television VHF - low energy ~10^-9 electron volts
• Television UHF
• Radar
• Microwaves (including ovens)
• Infrared (heat) radiation
• Red-orange light
• Green-blue light
• Ultraviolet A
• Ultraviolet B
• Ultraviolet C

Ionizing

• Vacuum ultraviolet (absorbed by short path through air)
• Low energy X-rays
• Deep therapy X-rays - short wavelenght ~10^-14 meters
• Gamma rays (overlaps with X-rays) - high frequency ~10^22 Hz
• Cosmic photons - high energy ~100 million electron volts

* The ~ symbol indicates an approximate measure.