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.