Thursday, June 08, 2006
RADIATION HORMESIS
In response to a discussion on CCNet about radiation hormesis in which it was suggested that there is no way, at the purely cellular level, that radiation could be beneficial because it destroys at the molecular level I wrote.
"While theoretical reasons for the hormesis effect are weak, arguably because it is not a well researched field, it has been proven for a century that radiatiion hormesis does work in the laboratory on bacterial cultures & plants. It can be argued whether the evidence is sufficient to conclude that it works also for large multicellular life forms such as tigers & ourselves (I think it is) but it certainly works at the cellular level.
Support for hormesis in the laboratory can be found here
" Bhattarcharjee in 1996 showed that when the mice preirradiated with just adapting doses of 1 cGy/day for 5 days (without a challenge dose), thymic lymphoma was induced in 16% of the animals (Bhattarcharjee 1996). Interstingly, when preirradiated mice were exposed to a 2 Gy challenge dose, thymic lymphoma was induced again in 16% of the animals. However, the challenge dose alone, induced thymic lymphoma in 46% of the mice. From these results, it can be concluded that the low dose preirradiation possibly cancel the induction of thymic lymphoma by the 2 Gy challenge dose. In 1996, Azzam and his colleagues showed that a single exposure of C3H 10T1/2 cells to doses as low as 0.1 cGy reduces the risk of neoplastic transformations. They suggested that a single low-dose at background or occupational exposurelevels, may reduce cancer risk."
In a less scientific part of the same article we see that just as it used to be entirely PC to fear global cooling at one time the beneficial effects of radioactivity were entirely trendy
"While theoretical reasons for the hormesis effect are weak, arguably because it is not a well researched field, it has been proven for a century that radiatiion hormesis does work in the laboratory on bacterial cultures & plants. It can be argued whether the evidence is sufficient to conclude that it works also for large multicellular life forms such as tigers & ourselves (I think it is) but it certainly works at the cellular level.
Support for hormesis in the laboratory can be found here
" Bhattarcharjee in 1996 showed that when the mice preirradiated with just adapting doses of 1 cGy/day for 5 days (without a challenge dose), thymic lymphoma was induced in 16% of the animals (Bhattarcharjee 1996). Interstingly, when preirradiated mice were exposed to a 2 Gy challenge dose, thymic lymphoma was induced again in 16% of the animals. However, the challenge dose alone, induced thymic lymphoma in 46% of the mice. From these results, it can be concluded that the low dose preirradiation possibly cancel the induction of thymic lymphoma by the 2 Gy challenge dose. In 1996, Azzam and his colleagues showed that a single exposure of C3H 10T1/2 cells to doses as low as 0.1 cGy reduces the risk of neoplastic transformations. They suggested that a single low-dose at background or occupational exposurelevels, may reduce cancer risk."
In a less scientific part of the same article we see that just as it used to be entirely PC to fear global cooling at one time the beneficial effects of radioactivity were entirely trendy
In the early days of X-rays and radioactivity it was generally believed that ionizing radiation has numerous beneficial effects. It was claimed that blindness might be cured by X-rays. Ladies corsets contained radium! Drinking mineral water containing radium was very popular. People went to spas to drink radioactive water or stayed for hours in caves to be irradiated by ionizing radiation (for a review see Wolff 1992). Between 1925 and 1930 over 400,000 bottles of distilled water containing radium 226 and radium 228 were sold. It was advertised that some mixtures could treat over 150 disease, especially lassitude and sexually impotence (Macklis 1990).Actually if you go back to, at least, the times of the ancient Romans "taking the waters" at volcanic springs has been considered useful. Apart from the presence of sulpher in such water its main difference from rain is a very high rate of radioactivity. The Romans obviously could not measure this but did see effects.
Labels: Hormesis
