Saturday, February 20, 2016

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.