[ RadSafe ] Re: Residential radon risk

[niton at mchsi.com]

Dear Otto,

I appreciate your perspective and believe your findings with beagles are valid.

However, I am not sure how far you can extend observations from beagles given 
their relatively shorter lifespan as compared to humans and other obvious 
differences.

The confounding of the residential radon studies generally reduces the observed 
risk as does the use of radon exposure instead of dose.  We have shown that the 
risk estimates for radon exposure increases as more accurate measures of 
exposure are used. http://www.aarst.org/news_pdf/2002_IowaU_Follow-up_Study.pdf

Dr. Cohen's inverse relationship is seen with smoking related cancers but not 
with non smoking related cancers.  Dr. Cohen interprets this as some hormetic 
effect; I interpret it as residual confounding from smoking.  The North 
American and European case-control poolings have both documented a risk even at 
an average exposure of 3 pCi/L.  I believe this is an under estimate of the 
true risk based on the link above.  

Further, we have recently found a gene that if missing increases radon-induced 
lung cancer risk by 3 fold.  This finding was found in NEVER smokers.

I would urge Health Physicist not to dismiss the important health risk posed by 
radon.  

The rather outdated HPS position statement on radon states, "Encourage and 
Support Additional Research. Although we know a great deal about radon and its 
potential effects on health, there is still much we do not know and could 
benefit from learning. The EPA and other governmental agencies concerned with 
radiological health should encourage and fund additional research by competent 
qualified scientists to improve our understanding of the risks of radiation and 
the means to mitigate those risks." http://hps.org/documents/indoorradon.pdf

I realize that some folks feel that the only qualified scientists are those 
that find an inverse association.  But time has come to accept the fact that 
prolonged residential radon exposure (even at concentrations below the EPA 
action level) increases lung cancer risk.  Downplaying the risk posed by 
prolonged radon exposure is a public health disservice.

Best Regards, Bill Field