If we really believed in the LNT, we would have to conclude that routine use of X-rays for medical purposes would cause 100,000 deaths each year. - Richard North, Alpha, 1997
Radiation and cancer are certainly strange bedfellows.
On the one hand there is a great deal of misplaced concern that the almost infinitesimally small emissions from nuclear power plants will cause widespread cancer and induce Farmer Jones's cow to give birth to two-headed calves. Yet when Farmer Jones contracts cancer (no doubt as a result of the power plant), one of the primary treatments is to destroy the cancer cells (which are unusually susceptible to radiation) with X-ray treatments or by implantation of radioactive "seeds" in the cancerous organ. And when Mrs. Farmer Jones has a hyperactive thyroid, she ingests enough iodine 131 to give her body 200 times the radiation dose - in about three weeks - that she receives over her lifetime from the natural background, to to mention the gamma radiation given to her good farmer husband from being next to him in bed. Furthermore, when little Billy Jones is found to have a fatal, inoperative brain tumor, the least invasive treatment is the "gamma knife" - a method of focusing 201 small gamma sources, which, individually, are too weak to cause any harm to anyone but the most fervent anti-nuke. Yet when they are concentrated on the offending growth together they have the power to vaporize it... and Billy goes home that afternoon completely cured. Is that a miracle or what?
However, we are not going to discuss this type of radiation therapy, since it involves the transfer of considerable amounts of energy to tissues - particularly tumors or cancers - in an attempt to destroy them or reduce their functionality. Instead, we will be concerned about the effects of comparatively tiny amounts of radiation whose purpose is to provoke the immune system into stepping up its action on the cellular level.
You may note in this chapter that virtually all of the current experimental activity mentioned is occurring in Japan, where the work of Dr. Luckey is revered - since, I suspect, it explains so much of what is happening to bomb survivors. But he Japanese have taken the matter much further, including hormetic augmentation of high-level therapies and measurement of the physiological reactions to radiation - including one that gives credence to an unusual treatment for arthritis that dates back to Roman times.
Showing posts with label cancer. Show all posts
Showing posts with label cancer. Show all posts
Sunday, March 13, 2016
Wednesday, March 2, 2016
The Most Toxic Substance on Earth?
One of the noisiest guns in the anti-nuclear arsenal has been the cultivated fear of plutonium. "The most toxic substance known to man," so the mantra goes - in complete disregard to toxicity studies showing the element to be about as toxic as caffeine and 1/1,000,000,000,000 the toxicity of botulism toxin. Even in the health physics field, however, there has been a great deal of concern over inhaled plutonium, because it is an alpha emitter shooting nuclear cannon balls directly into adjacent lung tissue. If you presume radiation is a major cause of cancer, it is only logical to see chronic exposure from an alpha source within the lungs as extremely dangerous. But just as with radon exposure in mining environments, plutonium may not be nearly as dangerous as earlier believed.
During the urgent atomic bomb development period of 1944-45, some workers were exposed to plutonium fumes and extremely fine dust, which accumulated primarily in lung tissue. Twenty-six of these exposed males were followed with regular examinations every five years starting in 1952. When the initial study of these examinations began in 1973 [Hempelmann, L.H. et al. Manhattan Project plutonium workers. A twenty-seven year follow-up study of selected cases. Health Physics, 25, 461, 1973], one subject had already died of a heart attack. Anti-nuclear scientists, such as John Gofman, predicted shortened life spans from radiation-induced lung cancer. [Gofman, J.W., Radiation and Human Health, Sierra Clue Books, San Francisco, 1981.]
But apparently, someone forgot to tell the workers.
At the time of the 1986-87 examination period, with an average of age of sixty-six years, twenty-two of the twenty-five subjects had refused to die on Gofman's schedule. One had died in an automobile accident, another of a heart attack at age sixty-two, and the third - a pack-a-day-plus smoker - had succumbed to lung cancer in his seventy-second year. (It may be of some interest that this person, identified as Subject #10, was in the lower half of estimated plutonium deposits.)
Because only twenty-six individuals were involved, the study has no statistical significance - which is to say that chance could have been at work selecting certain men who were unusually tolerant to the effects of inhaled plutonium. But the data is also suggestive of a lesser response to plutonium than the LNT dose-response would predict.
Anti-nuclear activists are fond of saying that "a single gamma ray can lead to cancer." Eight of the atomic bomb workers - all living at the end of 1987 - had received a dose of more than 2,000,000,000,000,000 alpha particles, which is the equivalent of 8,000,000,000,000,000 gamma rays (assuming a Q of 4). Not only were the "victims" alive, but they were healthier than their peers who weren't lucky enough to inhale plutonium dust more than forty years earlier.
If this study were the only one indicating a biopositive dose-response from plutonium ingestion, it might be written off as an anomaly. But, quoting from a paper by Voelz and Lawrence [Voelz, G.L. and Lawrence, J.N.P. A forty-two-year medical follow-up of Manhattan Project plutonium workers. Health Physics, Vol. 61, 1991. For more information, you might also refer to Voelz, G.L. et al. Mortality study of Los Alamos workers with higher exposures to plutonium. Epidemiology applied to health physics. Proceedings of the Health Physics Society, Albuquerque, N.M. Report CONF-83010, 318, 1983]:
"Other studies of Pu-exposed workers have not demonstrated excesses of lung cancer. In 224 white male Pu-exposed workers, selected on the basis of each having a 1974 estimated Pu deposition in excess of 370Bq (10 nCi), only one death from lung cancer occurred over at 33-year follow-up period. The SMR for lung cancer based on U.S. rates was 0.2 (95% C.I.=0,1.1)."
Lest you have forgotten the definition, an SMR of 0.2 means that the lung cancer rate for the workers exposed to plutonium was one-fifth that of the general population.
Don't take this as an indication that plutonium is never dangerous when ingested. All the heavy metals are toxic to some degree, and though a relatively benign alpha emitter, it has the potential for being dangerous in large amounts. Several studies noted by Voelz in which beagles were exposed to very high doses produced extremely severe consequences. But hormesis is about the differences in effects of a toxin depending on the dose and/or dose rate. Evidence in these studies clearly suggests that plutonium may be an effective hormetin.
During the urgent atomic bomb development period of 1944-45, some workers were exposed to plutonium fumes and extremely fine dust, which accumulated primarily in lung tissue. Twenty-six of these exposed males were followed with regular examinations every five years starting in 1952. When the initial study of these examinations began in 1973 [Hempelmann, L.H. et al. Manhattan Project plutonium workers. A twenty-seven year follow-up study of selected cases. Health Physics, 25, 461, 1973], one subject had already died of a heart attack. Anti-nuclear scientists, such as John Gofman, predicted shortened life spans from radiation-induced lung cancer. [Gofman, J.W., Radiation and Human Health, Sierra Clue Books, San Francisco, 1981.]
But apparently, someone forgot to tell the workers.
At the time of the 1986-87 examination period, with an average of age of sixty-six years, twenty-two of the twenty-five subjects had refused to die on Gofman's schedule. One had died in an automobile accident, another of a heart attack at age sixty-two, and the third - a pack-a-day-plus smoker - had succumbed to lung cancer in his seventy-second year. (It may be of some interest that this person, identified as Subject #10, was in the lower half of estimated plutonium deposits.)
Because only twenty-six individuals were involved, the study has no statistical significance - which is to say that chance could have been at work selecting certain men who were unusually tolerant to the effects of inhaled plutonium. But the data is also suggestive of a lesser response to plutonium than the LNT dose-response would predict.
Anti-nuclear activists are fond of saying that "a single gamma ray can lead to cancer." Eight of the atomic bomb workers - all living at the end of 1987 - had received a dose of more than 2,000,000,000,000,000 alpha particles, which is the equivalent of 8,000,000,000,000,000 gamma rays (assuming a Q of 4). Not only were the "victims" alive, but they were healthier than their peers who weren't lucky enough to inhale plutonium dust more than forty years earlier.
If this study were the only one indicating a biopositive dose-response from plutonium ingestion, it might be written off as an anomaly. But, quoting from a paper by Voelz and Lawrence [Voelz, G.L. and Lawrence, J.N.P. A forty-two-year medical follow-up of Manhattan Project plutonium workers. Health Physics, Vol. 61, 1991. For more information, you might also refer to Voelz, G.L. et al. Mortality study of Los Alamos workers with higher exposures to plutonium. Epidemiology applied to health physics. Proceedings of the Health Physics Society, Albuquerque, N.M. Report CONF-83010, 318, 1983]:
"Other studies of Pu-exposed workers have not demonstrated excesses of lung cancer. In 224 white male Pu-exposed workers, selected on the basis of each having a 1974 estimated Pu deposition in excess of 370Bq (10 nCi), only one death from lung cancer occurred over at 33-year follow-up period. The SMR for lung cancer based on U.S. rates was 0.2 (95% C.I.=0,1.1)."
Lest you have forgotten the definition, an SMR of 0.2 means that the lung cancer rate for the workers exposed to plutonium was one-fifth that of the general population.
Don't take this as an indication that plutonium is never dangerous when ingested. All the heavy metals are toxic to some degree, and though a relatively benign alpha emitter, it has the potential for being dangerous in large amounts. Several studies noted by Voelz in which beagles were exposed to very high doses produced extremely severe consequences. But hormesis is about the differences in effects of a toxin depending on the dose and/or dose rate. Evidence in these studies clearly suggests that plutonium may be an effective hormetin.
Sunday, February 14, 2016
Who's the Leader of the Gang...
Irradiation of the pregnant animals - and the foetuses in utero caused an astonishing decrease of the mortality rate of the infected baby mice. [Mayr and Paulas, Unexpected effects of a whole body irradiation on the mortality rate of baby mice after an experimental infection with the vesicular stomatitis virus (VSV), Zentralbl. Veterinaermed, 36, 577, 1989.]
As a rule, I don't think much of animal experiments. No, I'm not a member of People for the Ethical Treatment of Animals (PETA); in fact, I think many test animals (that would have never existed were it not for testing requirements) have it a whole lot better than their cousins who live in the wild. Can you th ink of anything worse than being a mouse that is in the process of being swallowed whole by a snake? And besides not having to be constantly on the lookout for snakes, cats, and hawks, some of these test critters have a pretty active social life - especially those involved in reproductive studies.
My problem with much of the animal testing is similar to the problem I have with the LNT - it is based on extrapolation with no consideration of a possible (and likely) threshold. For example, cancer researchers will load up some rat - which has been bred for a propensity to have tumors - with the human equivalent of two boxcars per day of an artificial sweetener, and then declare the substance to be a human carcinogen when a few tumors appear. No consideration is given to the possibility that there is a threshold, above which the rat's resistance is overwhelmed, but below which there is no effect.
Fortunately, mouse experiments related to disproving the LNT and demonstrating hormesis are not in this category. A single datum point on the accompanying graphs is often the average of hundreds of mouse lifetimes, and the curves subsequently drawn lie within the range of these experimental data so that no extrapolation is necessary. Besides most of the tested mice should be happy campers, since ionizing radiation in the hormesis range generally promotes health and longevity.
This chapter will look into the effects of low-level (and a few not so low-level) X-rays and gamma radiation on the mice. Most of it is related to cancer, sinc, as we are aware, this disease is commonly associated with radiation and is, in fact, the major detrimental effect of exposure. Other topics include growth rate, life span, radio-resistance (which all parents of teenagers should have), and one inexplicable effect of radiation received by the parents of the test mice.
In the following studies, exposures (rads/Gy) and doses (rems/Sv) are equal, since only gamma and X-ray radiation are involved.
As a rule, I don't think much of animal experiments. No, I'm not a member of People for the Ethical Treatment of Animals (PETA); in fact, I think many test animals (that would have never existed were it not for testing requirements) have it a whole lot better than their cousins who live in the wild. Can you th ink of anything worse than being a mouse that is in the process of being swallowed whole by a snake? And besides not having to be constantly on the lookout for snakes, cats, and hawks, some of these test critters have a pretty active social life - especially those involved in reproductive studies.
My problem with much of the animal testing is similar to the problem I have with the LNT - it is based on extrapolation with no consideration of a possible (and likely) threshold. For example, cancer researchers will load up some rat - which has been bred for a propensity to have tumors - with the human equivalent of two boxcars per day of an artificial sweetener, and then declare the substance to be a human carcinogen when a few tumors appear. No consideration is given to the possibility that there is a threshold, above which the rat's resistance is overwhelmed, but below which there is no effect.
Fortunately, mouse experiments related to disproving the LNT and demonstrating hormesis are not in this category. A single datum point on the accompanying graphs is often the average of hundreds of mouse lifetimes, and the curves subsequently drawn lie within the range of these experimental data so that no extrapolation is necessary. Besides most of the tested mice should be happy campers, since ionizing radiation in the hormesis range generally promotes health and longevity.
This chapter will look into the effects of low-level (and a few not so low-level) X-rays and gamma radiation on the mice. Most of it is related to cancer, sinc, as we are aware, this disease is commonly associated with radiation and is, in fact, the major detrimental effect of exposure. Other topics include growth rate, life span, radio-resistance (which all parents of teenagers should have), and one inexplicable effect of radiation received by the parents of the test mice.
In the following studies, exposures (rads/Gy) and doses (rems/Sv) are equal, since only gamma and X-ray radiation are involved.
Thursday, February 11, 2016
Rummaging Through the Stacks
Where the radiation level is greater, cancer risk is invariably less. [Nambi and Soman. Further observations on environmental radiation and cancer in India, Health Physics, submitted in 1990, unpublished.]
Presenting the evidence of radiation hormesis has been the most daunting problem faced in writing this book; there is just too much of it. Luckey had more than 2,000 citations in his two books, and he estimates that this was about half of the data available in 1990. [Hormesis with Ionizing Radiation, CRC Press, Boca Raton, 1980; and Radiation Hormesis, CRC Press, Boca Raton, 1991.]
In the fifteen years since then, other researchers have become involved, and their research compounds the problem of "too much" evidence. Until of late there had been only a very few experiments designed to address the radiation hormesis hypothesis, and most of these involved non-vertebrates. [Even more rare are subambient (i.e., less than normal background) radiation experiments, which should show a degradation of biologic function when the target microbes are shielded from cosmic and other background sources. Two such experiments are described in Radiation Hormesis, pp. 211-23.]
The data available - which are the backbone of the argument I'm putting forth [While I have absolutely no reason to distrust the recent test reports that attest to the hormesis phenomenon, there is something very satisfying about examining data taken without any conceivable bias toward "the reverse effect." If there were any bias it was to ignore that which didn't fit the curve.] - are generally one of the following types:
It would be wonderful if there were carefully controlled experimental data on humans for all diseases over the complete radiation dosage range. To optimize the hormesis effect, it would be marvelous to have double-blind studies over long periods of time, with carefully controlled exposures and rates. But we don't have these things.
Presenting the evidence of radiation hormesis has been the most daunting problem faced in writing this book; there is just too much of it. Luckey had more than 2,000 citations in his two books, and he estimates that this was about half of the data available in 1990. [Hormesis with Ionizing Radiation, CRC Press, Boca Raton, 1980; and Radiation Hormesis, CRC Press, Boca Raton, 1991.]
In the fifteen years since then, other researchers have become involved, and their research compounds the problem of "too much" evidence. Until of late there had been only a very few experiments designed to address the radiation hormesis hypothesis, and most of these involved non-vertebrates. [Even more rare are subambient (i.e., less than normal background) radiation experiments, which should show a degradation of biologic function when the target microbes are shielded from cosmic and other background sources. Two such experiments are described in Radiation Hormesis, pp. 211-23.]
The data available - which are the backbone of the argument I'm putting forth [While I have absolutely no reason to distrust the recent test reports that attest to the hormesis phenomenon, there is something very satisfying about examining data taken without any conceivable bias toward "the reverse effect." If there were any bias it was to ignore that which didn't fit the curve.] - are generally one of the following types:
- Animal tests designed to find adverse effects of high levels of ionizing radiation but which happened to take measurements in the low-dose area in the course of the experiment; [According to Luckey, much of the low-dose data - which showed negative correlation of the dose-response relationship - was either ignored, omitted or simply deemed too unimportant to report.]
- Japanese bombing survivors who were within a known distance of A-bomb detonations and whose exposures could be calculated; [There is considerable controversy about exposures, particularly in Hiroshima, with many researchers believing the data analysis understates the radiation dosage. One problem is related to some data still not being available to investigators - even after more than fifty years!]
- Statistical evidence on workers in nuclear power plants and weapons manufacturing facilities; and
- Populations that live in various areas with background radiation up to eighty times the U.S. average.
It would be wonderful if there were carefully controlled experimental data on humans for all diseases over the complete radiation dosage range. To optimize the hormesis effect, it would be marvelous to have double-blind studies over long periods of time, with carefully controlled exposures and rates. But we don't have these things.
Friday, February 5, 2016
Chernobyl - Symbol of Unconcerned Totalitarianism
One can hardly compare the Chernobyl fire in the Ukraine to the alleged "Three Mile Island disaster" in Harrisburg, Pennsylvania. Thirty-one firement and plant workers were killed in the former, while the only victims at TMI were from media-caused anxiety. Volumes have been written by analysts on the mistakes made a both power plants. But Chernobyl, with its graphite reactor designed to produce weapons-grade plutonium as well as electricity - and with no containment building - cannot even be compared with the pressurized water reactor (PWR) at TMI in which the nuclear reaction is stopped by the laws of physics when there is a loss of coolant water. Of course that hasn't stopped the anti-nuclear, anti-technologists from trying. But perhaps the strangest story out of Chernobyl was that the Soviet hierarchy, who had strongly supported the anti-nuclear activists in the United States, were apparently led to believe their own propaganda about radiation dangers.
The accident at Chernobyl provided both good and bad news for anti-nuclear activists. For decades, they had been attempting to come up with some reasonable way that radioactive products from nuclear power plants could be spread over the countryside. The best they'd been able to come up with for U.S. power plants went like this:
(a) A loss-of-coolant accident occurs, and the emergency core cooling systems fail to operate, leading to a meltdown of the fuel assemblies inside the reactor.
(b) Although the nuclear reaction stops when the coolant is lost (the water acts as a moderator to slow down the neutrons so they can be captured and allow the reaction to continue), there is still heat generated from the decay of the "daughters" of the reaction. This is supposedly so intense that it melts through six inches of steel in the reactor vessel, and continues through many feet of high-strength, reinforced concrete.
(c) But it can't stop there. The molten mass must then continue to melt through perhaps a few hundred feet of earth until reaching an aquifer. There the steam generated causes "blow holes" to develop, and the steam carries the radioactive products back to the surface. (Hold on, we're almost there.)
(d) The weather must cooperate with a gentle breeze blowing toward a populated area. (Too much wind and our "cloud" dissipates; under calm conditions, the product settles to the earth at the facility and is taken care of there.)
But the graphite fire at Chernobyl provided an actual way that about 90 million curies of radioactive material could be efficiently spread around the countryside. Yes, the anti-nukes got their dream of a large scale nuclear disaster - which had been becoming more and more difficult to conjure up, given the fact that Three Mile Island showed that the uncovered fuel elements couldn't even melt through the reactor vessel.
But there was bad news for them also. There weren't any bodies on the streets. Aside from those who died on-site, mostly firemen who expired from burns with possibly complications from radiation, there is no sign of a cancer epidemic or any other chronic problems.
Oh, sorry, there's one. The governments involved are going broke (broker?) from the payments they are making to victims. Victims? Didn't I just say there weren't any victims? Yes, but I meant from the radiation. The victims as defined by the governments involved are those who were traumatized by fear of radiation or from the trauma of being evicted from their homes and forced into refugee camps.
Of the radionuclides escaping from the burning graphite reactor at Chernobyl, the one of most concern was cesium 137. A gamma emitter with a half-life of thirty years, this reactor product settled to Earth over much of Europe. Yes sir, it did. But nobody seemed to notice it settled right on top of soil that already contained naturally occurring radioisotopes such as U238, Th232, and K40. In a mistaken spirit of humanitarianism, the Soviet Army evacuated its citizens when the dose from the Earth exceeded 0.5 cGy (500 mrad) per year. [One of the purposes of this book is to show how some authorities - even nuclear officials - have no connection with reality and, indeed, make recommendations and rules that cause great harm. This example shows nationality is no barrier.]
They apparently didn't notice they were already sitting on "highly radioactive" dirt. Figure 5 shows the Chernobyl contamination relative to naturally occurring radiation. Is it any wonder that the "Project Team's Main Recommendations" included the following?
"Measures with less impact on traditional agriculture should be investigated; better public information is needed, particularly on doses and risks, and studies of the acceptability to people of living in contaminated areas." [Emphasis added.]
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
|
|
Table 11 gives another look at the Cs 137 "fallout" and the natural radionuclides in the top 10 cm (about four inches) of soil in several locations around Chernobyl. Note the range of natural soil radiation. Wouldn't you think that someone would have noticed a variation in the detrimental effects of natural radiation when some areas had thirty-six times the soil radioisotopes of others - if indeed there were any detrimental effects? Would you think one area would be known as Cancervania - because of regular affliction of the populace from radiation, while another area would go by Vitalia, because of superior health derived from a dearth of radiation exposure? But we don't see Europe having such disparities in cancer or other immune disorders on the basis of location, do we?
Well, actually we do: the health resorts are almost always located on springs with a high radon content.
Wednesday, February 3, 2016
You Can Run, But You Can't Hide
If an increase in low-level background radiation caused any problems, decades of anecdotal evidence would have made Denver a ghost town.
No one escapes radiation. As mentioned earlier, the average person receives 15,000 "hits" each second, while a medical X-ray may easily score some 100 billion cellular incidents. [Risk of Nuclear Power by Bernard L. Cohen, University of Pittsburg professor. You can read the entire article at http://www.physics.isu.edu/radinf/np-risk.htm.]
Those who say that "it takes only one gamma ray to cause cancer" may be technically correct, but they neglect to mention a small statistical detail: The odds against any particular gamma ray causing cancer in an affected cell are 1 out of 30,000,000,000,000,000. (That's 30 quadrillion, or 30 x 10^15, to one.) Besides, hormesis evidence indicates that the gamma ray of concern is more likely to prevent cancer than to cause it.
Before defining the units used to measure radiation exposure, you may recall we used the SXR (shoe X-ray) as a yardstick to compare the dangers posed by various radiation sources. As you may have guessed, the SXR is not exactly a reference unit recognized by the scientific community. A more convenient benchmark would be the average background exposure that we receive from the various natural and man-made sources. But, as we'll see, this "natural background" value varies by a factor of a hundred or so in different locales on planet Earth - almost all of which is the fault of nature, not man. Still, it would be desirable to reference other levels of radiation to some normal amount; so we'll arbitrarily use, as a definition of "natural background," the exposure to the average U.S. citizen - previously mentioned to be 300 mrem from natural sources and 63 mrem from man-made (mostly medical) origins.
Until the twentieth century, the average background dose of radiation for a human being had continually decreased over our specie's existence because of the slow decay of the primordial radionuclides such as thorium 232, uranium 238, and potassium 40. So what happened during the 1900s that turned the curve upward?
Most people would answer (a) fallout from atom/hydrogen bomb testing, and (b) nuclear power plants. Nice try, but no cigar. Bomb tests did inject huge amounts of highly radioactive materials into the atmosphere, where most decayed to safe levels within ten days of testing. Other longer-half-life isotopes from fallout caused a temporary worldwide increase of background radiation in the neighborhood of 1% to 4% depending mainly on location. [The one of primary concern being strontium 90 with a half-life of twenty-nine years and a propensity to replace calcium in bones.] Today it amounts to less than 1/1000 of the average background level. As mentioned, there has been only a single "fall-out fatality" from atom/hydrogen bomb testing, which occurred on the misnamed Lucky Dragon. While anti-nuclear statistics have killed off many (theoretical) thousands in their quest for an atomic scapegoat, our inaccurate friends have been unable to directly attribute any other death or injury to radiation from fallout, except as a statistical article-of-faith based on the discredited LNT and "collective dose" theories.
Nuclear power plants, on the other hand, have known emissions of radioactive products such as xenon (a non-reactive "noble" gas), but these are so low in practice as to be immeasurable. It is calculated that the average U.S. resident receives a dose considerably less than 1 mrem from all nuclear power plants combined - again, as with fallout, about 1/1000 of the normal background radiation. For those truly troubled by potential radiation exposure, it is not necessary to avoid being in the vicinity of power plants, but you might want to stay away from the U.S. Capitol building and Grand Central Station, both of which emit considerably more radiation than would be legal for any U.S. nuclear power plant to emit.
So where did the increase come from?
If we are to believe a report from the National Academy of Sciences Committee on the Biological Effect of Ionizing Radiation (BEIR IV), most of the increase came from weather-stripping storm doors, and polyethylene wrapping of new homes. Not that any of these products was unusually radioactive, but because they made houses "tight," thus causing radon gas, which bubbles up from decaying radionuclides in the soil, to be trapped in the living areas. This, they calculate, amounts to 200 mrem per year - unless, as well shall see, you are fortunate enough to get more.
The second largest component of the increase is from X-rays and nuclear medicine. The averages used for medically related exposures are somewhat misleading, however, since they range from a 1-mrem dental X-ray to about 100,000 mrem (100 cGy) for a thyroid ablation. [In 1979, the University of Michigan outfitted the husband of a woman undergoing radioactive iodine diagnosis with a dosimeter. They found that he received a dose of 2,500 mrem(!) during their vacation - which would no doubt cause the EPA to forbid them to sleep together.]
In other words, most people fall well below the combined 53 mrem medical dose, while a few have relatively massive doses. As the evidence section will show, even these huge doses of X-rays or medical radioisotopes produce no measurable increase in cancer - and indeed are seen to have a hormetic effect in those cases where low-level effects were investigated.
Finally, about 10 mrem comes from consumer products such as smoke detectors, television receivers, and tritium watch dials. None comes from the process of food irradiation for a very simple reason: The process physically can not make the food radioactive. Does having an X-ray make you radioactive? Same thing.
Table 9 gives a breakdown of sources in the United States, according to the BEIR committee. Obviously, for most of us, our largest dose of radiation comes from natural sources. The exposures from "man-made" sources are almost entirely voluntary. If you don't want to have a dental X-ray, then don't. If your doctor wants to check your thyroid function using iodine 131, tell him, "No thanks, I'll just feel awful for the rest of my life." If you don't want a smoke detector in your home, then don't buy one; burn your family up if that's your preference. Don't watch television or use a computer terminal.
But to avoid the natural background radiation, you need to take some pretty serious steps. Moving to Antarctica or living underwater in a nuclear submarine are your best bets. Or you could also move from high-background-radiation Colorado (with a low age-adjusted cancer death rate) to the low-background-radiation southeastern and eastern coastal states (with high age-adjusted cancer death rates). Then again, you might move out of your high-radon-exposure home in the Reading Prong of Pennsylvania to an area with a lower radon dose rate... but with a higher lung cancer toll.
You're not going to do any of these things. Why? Because if an increase in low-level background radiation caused any problems, we would see evidence - in the form of dead bodies. Decades of anecdotal evidence would have made Denver a ghost town, and Leadville, Colorado - the city with the highest altitude, therefore the most cosmic radiation - would have only monuments to its former short-lived citizens. But the only people who think that there is any such danger are the regulators, anti-nuclear activists, "environmentalists," and government scientists - who cling to the Linear No-Threshold (LNT) Hypothesis. We will be discussing this concept as applied to ionizing radiation, but since our government is so concerned about the doses we receive in this country, let's see what the situation would be if we lived with the background radiation experienced by fellow human beings who live in places outside the United States.
Remember, the average background radiation in the United States is 300 mrem (.3 cGy) plus an average of 63 mrem, primarily from medical sources. And remember that the radiation rules-makers are out to regulate public exposures down to a single mrem (.001 cGy); they intend to put a limit on public exposures at 100 mrem (0.1 cGy).
No one escapes radiation. As mentioned earlier, the average person receives 15,000 "hits" each second, while a medical X-ray may easily score some 100 billion cellular incidents. [Risk of Nuclear Power by Bernard L. Cohen, University of Pittsburg professor. You can read the entire article at http://www.physics.isu.edu/radinf/np-risk.htm.]
Those who say that "it takes only one gamma ray to cause cancer" may be technically correct, but they neglect to mention a small statistical detail: The odds against any particular gamma ray causing cancer in an affected cell are 1 out of 30,000,000,000,000,000. (That's 30 quadrillion, or 30 x 10^15, to one.) Besides, hormesis evidence indicates that the gamma ray of concern is more likely to prevent cancer than to cause it.
Before defining the units used to measure radiation exposure, you may recall we used the SXR (shoe X-ray) as a yardstick to compare the dangers posed by various radiation sources. As you may have guessed, the SXR is not exactly a reference unit recognized by the scientific community. A more convenient benchmark would be the average background exposure that we receive from the various natural and man-made sources. But, as we'll see, this "natural background" value varies by a factor of a hundred or so in different locales on planet Earth - almost all of which is the fault of nature, not man. Still, it would be desirable to reference other levels of radiation to some normal amount; so we'll arbitrarily use, as a definition of "natural background," the exposure to the average U.S. citizen - previously mentioned to be 300 mrem from natural sources and 63 mrem from man-made (mostly medical) origins.
Until the twentieth century, the average background dose of radiation for a human being had continually decreased over our specie's existence because of the slow decay of the primordial radionuclides such as thorium 232, uranium 238, and potassium 40. So what happened during the 1900s that turned the curve upward?
Most people would answer (a) fallout from atom/hydrogen bomb testing, and (b) nuclear power plants. Nice try, but no cigar. Bomb tests did inject huge amounts of highly radioactive materials into the atmosphere, where most decayed to safe levels within ten days of testing. Other longer-half-life isotopes from fallout caused a temporary worldwide increase of background radiation in the neighborhood of 1% to 4% depending mainly on location. [The one of primary concern being strontium 90 with a half-life of twenty-nine years and a propensity to replace calcium in bones.] Today it amounts to less than 1/1000 of the average background level. As mentioned, there has been only a single "fall-out fatality" from atom/hydrogen bomb testing, which occurred on the misnamed Lucky Dragon. While anti-nuclear statistics have killed off many (theoretical) thousands in their quest for an atomic scapegoat, our inaccurate friends have been unable to directly attribute any other death or injury to radiation from fallout, except as a statistical article-of-faith based on the discredited LNT and "collective dose" theories.
Nuclear power plants, on the other hand, have known emissions of radioactive products such as xenon (a non-reactive "noble" gas), but these are so low in practice as to be immeasurable. It is calculated that the average U.S. resident receives a dose considerably less than 1 mrem from all nuclear power plants combined - again, as with fallout, about 1/1000 of the normal background radiation. For those truly troubled by potential radiation exposure, it is not necessary to avoid being in the vicinity of power plants, but you might want to stay away from the U.S. Capitol building and Grand Central Station, both of which emit considerably more radiation than would be legal for any U.S. nuclear power plant to emit.
So where did the increase come from?
If we are to believe a report from the National Academy of Sciences Committee on the Biological Effect of Ionizing Radiation (BEIR IV), most of the increase came from weather-stripping storm doors, and polyethylene wrapping of new homes. Not that any of these products was unusually radioactive, but because they made houses "tight," thus causing radon gas, which bubbles up from decaying radionuclides in the soil, to be trapped in the living areas. This, they calculate, amounts to 200 mrem per year - unless, as well shall see, you are fortunate enough to get more.
The second largest component of the increase is from X-rays and nuclear medicine. The averages used for medically related exposures are somewhat misleading, however, since they range from a 1-mrem dental X-ray to about 100,000 mrem (100 cGy) for a thyroid ablation. [In 1979, the University of Michigan outfitted the husband of a woman undergoing radioactive iodine diagnosis with a dosimeter. They found that he received a dose of 2,500 mrem(!) during their vacation - which would no doubt cause the EPA to forbid them to sleep together.]
In other words, most people fall well below the combined 53 mrem medical dose, while a few have relatively massive doses. As the evidence section will show, even these huge doses of X-rays or medical radioisotopes produce no measurable increase in cancer - and indeed are seen to have a hormetic effect in those cases where low-level effects were investigated.
Finally, about 10 mrem comes from consumer products such as smoke detectors, television receivers, and tritium watch dials. None comes from the process of food irradiation for a very simple reason: The process physically can not make the food radioactive. Does having an X-ray make you radioactive? Same thing.
Table 9 gives a breakdown of sources in the United States, according to the BEIR committee. Obviously, for most of us, our largest dose of radiation comes from natural sources. The exposures from "man-made" sources are almost entirely voluntary. If you don't want to have a dental X-ray, then don't. If your doctor wants to check your thyroid function using iodine 131, tell him, "No thanks, I'll just feel awful for the rest of my life." If you don't want a smoke detector in your home, then don't buy one; burn your family up if that's your preference. Don't watch television or use a computer terminal.
Table 9
|
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Sources of Average Annual Radiation for a U.S.
Citizen
|
|||
Natural
Sources
|
mrem/yr
|
cSv/yr
|
%
Total
|
Radon
|
200
|
0.2
|
55
|
Cosmic*
|
27
|
0.027
|
8
|
Terrestrial
|
28
|
0.028
|
11
|
Internal
|
39
|
0.039
|
11
|
Total Natural
|
300
|
0.3
|
82
|
Man-made
sources
|
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Medical X-rays
|
39
|
0.039
|
11
|
Nuclear medicine
|
14
|
0.014
|
4
|
Consumer goods
|
10
|
0.010
|
3
|
Nuclear power
|
< 1 **
|
< 0.001
|
-
|
Fallout
|
< 1
|
< 0.001
|
-
|
Total Man-made
|
63
|
0.063
|
18
|
TOTAL
|
363
|
0.363
|
100
|
* Doubles for every 6000 feet in
altitude.
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** The symbol “<” means “less than.”
|
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Source: Department of Energy Report
YMP-0337 from BEIR IV. Available in its entirety at http://www.ocrwm.doe.gov/factsheets/pdf/ymp0337rev1.pdf
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But to avoid the natural background radiation, you need to take some pretty serious steps. Moving to Antarctica or living underwater in a nuclear submarine are your best bets. Or you could also move from high-background-radiation Colorado (with a low age-adjusted cancer death rate) to the low-background-radiation southeastern and eastern coastal states (with high age-adjusted cancer death rates). Then again, you might move out of your high-radon-exposure home in the Reading Prong of Pennsylvania to an area with a lower radon dose rate... but with a higher lung cancer toll.
You're not going to do any of these things. Why? Because if an increase in low-level background radiation caused any problems, we would see evidence - in the form of dead bodies. Decades of anecdotal evidence would have made Denver a ghost town, and Leadville, Colorado - the city with the highest altitude, therefore the most cosmic radiation - would have only monuments to its former short-lived citizens. But the only people who think that there is any such danger are the regulators, anti-nuclear activists, "environmentalists," and government scientists - who cling to the Linear No-Threshold (LNT) Hypothesis. We will be discussing this concept as applied to ionizing radiation, but since our government is so concerned about the doses we receive in this country, let's see what the situation would be if we lived with the background radiation experienced by fellow human beings who live in places outside the United States.
Remember, the average background radiation in the United States is 300 mrem (.3 cGy) plus an average of 63 mrem, primarily from medical sources. And remember that the radiation rules-makers are out to regulate public exposures down to a single mrem (.001 cGy); they intend to put a limit on public exposures at 100 mrem (0.1 cGy).
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