Dose studies vs regs, cont'd

[BYRPV@ccmail.ceco.com]

     Radsafers,
     
     As I read through your responses to my original posting on this 
     subject, I realized that I mistakenly implied that a health physics 
     program should aim to expose all workers to 5 rem per year (the dose 
     that some believe to minimize cancer risk).  In fact, I believe the 
     purpose of dose limits is to ensure that any risk added to a radiation 
     worker due to his exposure to radiation does not exceed that of 
     so-called "safe industries" such as office work.  Examples of unsafe 
     industries are farming and mining.  Safety is measured in excess 
     deaths in 10,000 workers per year.
     
     From here on, let's imagine that science proves and the regs 
     acknowledge a 'j' shaped dose-response curve.  Even so, the nuclear 
     industry should not take on the role of a risk minimizer, that is, we 
     should not administer radiation to all of our workers just because 
     it's good for them.  We're not hurting anyone by not giving them 
     radiation dose.  Remember, if small exposures are beneficial, how can 
     witholding benefit be considered a detriment? 
     
     There must be a dose somewhere on the spine of the 'j' where the safe 
     industry risk of .05 additional deaths in 10,000 (or whatever) per 
     year is achieved.  If our role is to keep risk at or below that of a 
     safe industry, then as long as we keep the workers' occupational dose 
     less than that limit, we are doing our jobs.
     
     If a person wants to make his or her dose 5 rem after hours to 
     minimize cancer risk, that is up to them.  How can we as HPs be held 
     responsible if their occupational plus non occupational dose puts them 
     at higher risk than occupational alone?
     
     On the surface, the implementation of new regulations should be easy 
     to accomplish.  Just raise the annual limit to that "safe industry 
     risk" point on the spine of the 'j' and scale up intake, shipping, 
     burial, contamination, etc limits accordingly.
     
     Now, back to reality.  Its been said that we should remain 
     conservative with our dose response modeling because of mistakes made 
     in ignorance in the early days of radiation.  This argument is not 
     fair for at least two reasons.  First, the doses taken in tissues were 
     extremely high in cases such as the radium dial painters and earlly 
     physicists and radiologists--in the kRad range.  The effects were 
     mainly non-stochastic in nature since there was bulk tissue damage 
     done in these cases.  These cases do not compare with the occupational 
     range we're discussing.  Second, we've been at this for a hundred 
     years now!  How long do we have to wait before we are willing to admit 
     we have enough data gathered on what is surely the most studied and 
     best understood hazard known to man?.  Its been 50 years since the 
     bomb and we still have people waiting around for second and third 
     generation genetic effects.  The commercial nuclear industry has been 
     making power for almost forty years now.  Surely with the thousands of 
     careers spent in these and other reactor facilities, you'd think we'd 
     have enough information to quantify the risks by now.
     
     With the literally thousands of carcinogenic chemicals out there that 
     we think we fully understand, some of which have been discovered only 
     recently, why can't we as a community of professionals come to the 
     conclusion that ionizing radiation just isn't as harmful as was and is 
     commonly thought?  The mere fact that the effect is so small we can't 
     come to a consensus on just how small it is should tell us that its 
     too small to be a concern.
     
     Please forgive my ramblings.  I'm sure that to some, I'm preaching to 
     the choir and to others I'm a raving lunatic but to all, too 
     long-winded.
     
     Paul Vitalis
     byrpv@ccmail.ceco.com
     
     These opinions are mine alone and do not reflect those of my employer.