Unconventional Wisdom 4

Radiation Background—All Around and Underground

“Curmudge, I sense your dogged determination to convince our readers that (a) the LNT hypothesis has been disproven, and (b) radiation hormesis occurs.  This is the fourth posting in the current series —so readers should already know what we are talking about—plus we introduced the topic way back on August 8, 2011.”

“Don’t give us too much credit, Julie.  You and I can’t change how people think.  If we could, we’d be employed or at least put to better use as volunteers.  The most we can do is make readers aware of the existing science.  That through 2005 is found—as noted previously—via complete citations in Hiserodt’s book.  It’s up to our readers to convince themselves.  And remember, it’s easy to scare people but hard to un-scare them.”

“Time for some cold, hard facts, Old Guy.  We mentioned that the average background in the U.S. is 300 mrem per year with radon as the largest contributor.  Other typical background values in the U.S. are 200 mrem/yr in Gulf Coast states and 600 mrem/yr in the Denver area.  More extreme backgrounds are found elsewhere, e.g., 1,300 mrem/yr in Kerala, India and 48,000 mrem/yr in Ramasari, Iran.”

“Here is a situation, Julie, where background radiation is more than an academic question.  It can become a major financial issue.  In the U.S. if one is selling his house, he may be asked to have the radon concentration in his basement air checked.  If the radon is found to be above the EPA’s action level of 4 picocuries per liter of air, the prospective buyers may require the seller to have equipment installed to reduce the radon concentration.  This is due to concern about lung cancer thought to be caused by radon.  (Note: A curie is 37 billion disintegrations per second; a picocurie [pCi] is one trillionth of a curie.)”

“Because you brought it up, Curmudge, please tell me how Cohen and others studied the ‘concern about lung cancer caused by radon’.”

“Bernard Cohen of the University of Pittsburg (1995) (chap. 20 in Hiserodt’s book) collected radon exposure and cancer mortality data from 1,729 counties in the U.S. (90% of the population).  Cohen’s results showed an inverse relationship between lung cancer mortality and radon concentration.  The LNT theory would have predicted ‘4.5 deaths per 10,000 men per year for each pCi/L increase in airborne radon.’  Cohen’s research showed ‘a minus 4.7 deaths per pCi/L.’  More specifically, Cohen (1994, chap 17) studied residential radon vs. lung cancer rates.  In the Rocky Mountain states the lung cancer rate was 47 per 100,000 persons, and the average residential radon was 2.6 pCi/L.  In the Gulf Coast states the lung cancer rate was 68 per 100,000 persons, and the average residential radon was 0.5 pCi/L.  ‘The low-LET* component from radon progeny was probably responsible for the strong hormetic effect described for lung cancer’ (1).”

 

“Wow, Curmudge!  That helps explain the popularity over the centuries of the Gasteiner Heilstollen (Healing Gallery) in Bad Gastein, Austria as well as a lot of other spas in Europe.  The radon content in the healing gallery is advertised at over 1,000 times the EPA action level.  Too bad you didn’t stop there when you were in Austria; it might have helped your late wife’s arthritis.”

“There are similar but much more rustic ‘radon mines’ in the western U.S., Julie.  The oldest is the Free Enterprise Radon Health Mine in Boulder, Montana.  Barbra Erickson has studied and reported on the radon spas in Europe and the radon mines in the U.S. (2).”

“As I recall, Curmudge, chap. 17 of Hiserodt’s book describes studies in Asia of radon in spring water as well as in air.  Mortality from stomach cancer and all cancers was lower in a Japanese town with higher radon in its spring water (Mifune et al. 1992).  A similar trend was noted for lung cancer in indoor air.”

“And in China, Zhai et al. (1982) compared cancer mortality from geographical areas with ‘low background,’ ~100 mrem/yr, and ‘high background,’ ~330 mrem/yr (near U.S. average).  Nearly all cancers were less in the ‘high background’ area as were spontaneous abortions, neonatal mortality, and infertility.”

“So I guess we can conclude, Curmudge, that at the levels studied it’s healthier to live in a higher radiation background, whether it is in the air we breathe, the water we drink, or our total surroundings.”

“It looks that way, Julie, but at my age it doesn’t matter much.  What really concerns me is the mistaken fear of low-level radiation among younger people and our whole society.  In a subsequent posting we’ll speculate how life might be different if that unjustified fear were absent.”

Kaizen Curmudgeon

*LET (linear energy transfer).  Betas and gammas are low-LET radiation.

(1)  Sanders, C. L.  Dose-Response 10:619 (2012).

    

(2)  Erickson, B. L.  The therapeutic use of radon; a biomedical treatment in Europe; an ‘alternative’ remedy in the United Stated. Dose-Response 5:48-62 (2007).