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.

Parlez-Vous Radiation?

Using lower exposures than the Lorenz and Sacher experiments, a study by French researchers documented the effect of 900 mice - 300 controls, 300 receiving a chronic gamma ray dose at the rate of 7 cGy/year, and 300 exposed similarly to 14 cGy/year. [Caratero, A., Courtade, M., Bonnet, L., Planel, H., and Caratero, C. Effect of a continuous gamma irradiation at a very low dose on the life span of mice. Gerontology, 44, 272-76, 1998. These exposures are twenty-three to forty-six times the U.S. background level.]

Quoting from the abstracted results of the Gerontology article:

"The life span, after the beginning of the experiment, determined by the survival time of 50% of each population, is increased in irradiated mice: 549 in controls, 673 days in both irradiated groups. The differences are significant between the control and the irradiation mice. Differences between mice irradiated with 7 or 14 cGy are not significant."

So what did the researchers conclude?

"These results confirm the possibility of a non-harmful effect (hormesis) of ionizing radiation. They demonstrate that the paradigm, which states that low-dose effects can be predicted [by] high-dose effects, cannot be systematically applied in radiation biology in general and gerontology in particular."

Doesn't sound like there's much vacillation here, does it?

Before moving on to evidence on two-footed subjects, there are a couple of other unusual mouse studies that merit consideration.

Effects of Radiation on the Life Span of Mice

Surely if ionizing radiation has beneficial effects on growth rate and the immune system competence of mice, as evidenced by a decreased susceptibility to cancer, it ought to have a positive effect on life span. As several studies demonstrate, this is indeed the case.

A 1983 investigation by J.B. Storer [Storer, J.B., et al. Life shortening [sic] in Balb/C mice following brief protracted, and fractionated exposures to neutrons. Radiation Research, 96, 396, 1983] was cited by Luckey as an example of how hormesis effects are often overlooked by researchers who are expected a bio-negative response from radiation. [Radiation Hormesis, 1981, pp 46, 50.]

The authors ignored a peaking of longevity between 5 and 10 cGy, hopefully not in any attempt to be fraudulent or unethical, but probably because it would have appeared anomalous in terms of the LNT.

It is an earlier study [Sacher, G.A. and Grahn, G. Survival of mice under duration-of-life exposure to gamma rays. Journal of the National Cancer Institute, 32, 277, 1964] - which most certainly gave unintended results - that is of considerable interest to hormesis researchers. Life spans of mice - 90 in a control group, and 90 to 120 in four exposed groups - are plotted in Figure 10 on the basis of daily exposures to cobalt-60 gamma radiation. Exposures, which began 100 days after birth, were continued until the death of the specimen.

Caption for Figure 10 Life Span for Irradiated Mice  Source: Sacher, G.A., and Grahn, G. Survival of mice under duration-of-life exposure to gamma rays. I. The dosage-survival relation and lethality function. Journal of the National Cancer Institute, 32, 277, 1964; also ANL Report 6971, 1964, p 94.

Anti-nuclear activists, "animal rightists," and "popular wisdom" would predict dire consequences for test animals subjected to such huge doses of radiation every day of their lives. But this study offers substantial evidence that mice receiving 1,000 times their normal background dose had the longest life spans. [It is my understanding that similar results were reported by a researcher named Searle in 1964, but I have not been able to obtain any more information.] You might recall that, in the earlier discussion of growth rate, the optimum was also 1,000 times normal background.

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.