Re: EPA, risk and dose

["Frohmberg, Eric" <Eric.Frohmberg@STATE.ME.US>]

Well, yes and no.  I think what EPA's written guidance is saying is that 

there is "no simple direct conversion" from radiologic dose (in mrem per 

unit time) to risk.  (In fact, they are out there, really they are saying 

they don't like them).  Here we go - here is a quote from RERAM - Radiation 

Exposure and Risks Assmt Manual - EPA 402-R-96-016 page 1-9



"EPA does not recommend this method (calculating dose and applying a factor 

to convert to risk) and estimates of risk computed using this method are 

generally greater than those computed using the slope factor method; the 

magnitude of this discrepancy depends on the particular radionuclides and 

the exposure pathways for the site specific conditions, but can range from 

less than a factor of two to approximately one order of magnitude."



I don't think they are saying any of what you suggest below (except maybe 

that they don't like NRC dosimetry assumptions) - all of what you say are 

taken into account in their estimates of the cancer slope factor - eg all 

dosimetry type questions - the RBE, competing causes of death, etc. the 

model for absorption and distribution of various radionuclides - just as 

they are taken into account in the dose conversion factor.



It may be simplistic, but I really think they are just making it simpler for 

non-health physicists to estimate risk from a radiologically contaminated 

site.  It is a whole other question of whether that is a smart thing to do.



again, my thoughts, such as they are.

Eric F

Maine BOH





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