Monday, November 27, 2017

Japanese Geneticists on Radiation

I was searching for information using JSTOR, a historical index, and found this very interesting article:
Japanese Geneticists on Radiation (1957). Science, New Series, Vol. 126, No. 3263 (Jul. 12, 1957), pp. 68-69. Stable URL: Accessed: 27-11-2017 15:24 UTC "From what has been pointed out above, we are led to conclude that any amount of radiation, however small it may be, is deleterious to the heredity of man. Although a certain dose has been set as 'permissible' for people engaged in the operation of X-rays and radioactive apparatus or substances, this is only aimed at the safety and health of those people themselves. However, as far as the genetic effect on their descendants is concerned, there is no theoretical limit below which danger may be entirely excluded."

This argument that radiation produces irreparable errors in the DNA of eggs and sperm has not been contradicted, as this more recent study affirms:
Jacquet, P. (2004 Apr-Jun). Sensitivity of germ cells and embryos to ionizing radiation. Journal of Biological Regulators and Homeostatic Agents, 18(2): 106-114.
Abstract: Experiments performed in laboratory animals suggest that ionizing radiation can induce DNA damage in the germ cells of exposed individuals and lead to various deleterious effects in their progeny, including miscarriage, low birth weight, congenital abnormalities and perhaps cancer. However, no clear evidence for such effects has been found in epidemiological studies of people exposed to radiation. The predicted risks of hereditary effects of any kinds resulting from parental exposure to relatively low doses of ionizing radiation remain very low, compared to the spontaneous risks in the absence of irradiation. Irradiation of the mouse embryo can lead to various effects (lethality, growth retardation, congenital abnormalities), depending on the period of gestation at which irradiation occurs. In humans, prenatal irradiation has only been exceptionally associated with congenital abnormalities, but irradiation between weeks 8-25 has been shown to be able to induce severe mental retardation. Although being not proven, the risk of developing a childhood cancer following prenatal irradiation may also not be excluded. Like for genetic effects, the risk of adverse effects following exposure of the embryo to relatively low doses remains quite low compared to the natural risks.
Of course, the question of how much radiation is too much radiation remains contested and is, of course, subject to so many contingencies that a singular level will never be achieved.

Here are some of my thoughts on the potential relationship between autism and ionizing radiation that posits exposure as producing micro-deletions, as well as epigenetic changes, that may cause the mosaic of symptoms associated with the disorder, as well as other multi-factorial disorders, including diabetes:

Majia's Blog: Autism and Ionizing Radiation
May 23, 2014 - Diagnoses of autism are increasing and more researchers are concluding that environmental causes are contributing in significant ways to the ...

Majia's Blog: Autism and Exposure to Excess Ionizing Radiation: Is ...
A number of you have asked about the reaction to my paper on autism and ionizing radiation delivered at an international conference on autism in Cyprus: My paper argued for a systemic approach to understanding autism that deconstructed the idea that the body is separate from its environment: ...

Majia's Blog: Could Ionizing Radiation Play a Role in Autism? studying the effects of low-levels of ionizing radiation, I began to suspect a link to autism. I have found a possible mechanism. NK CD 56 cells are very radiosensitive and they have also been implicated as dysfunctional in children with autism. Maybe there is a connection here? Below are the steps I used in making this ...

And here is the snapshot of Fukushima Daiichi this morning, puffing away from unit 2, which has been especially steamy recently: