Re: Averill's Editorial

[GOODEN@VMS.OCOM.OKSTATE.EDU]

	I am pleased to see my cohort, George Vargo, contributing to the 
discussion on the LNT model of radiation injury.  It is important to 
specifically respond to the criticism that "Once again, we see a failure to 
understand the difference between deterministic and stochastic effects."  
This is probably an unfounded criticism for most of the radiation 
protection community, but it is certainly unfounded for those of us in the 
medical field who intentionally deliver radiation to patients every day to 
realize medical and health benefits.  Those of us with long careers in 
radiation therapy may have seen as many as 30,000 or more radiation 
threshold effects in our patients.  Almost every patient experiences 
deterministic effects during treatment.  

	I know of no failure to understand the difference between 
deterministic effects and stochastic effects among those who debate the 
scientific merit, or lack of it, in the LNT model.  For those who believe 
that science and reasoned principals do not support the LNT model, chronic 
radiation injury is not a stochastic effect.  In the present context, if 
the process is stochastic, it is described by the LNT model.  If the 
process is not described by the LNT model, then it is not stochastic.  

	It is interesting that the Averill article "saddened and 
embarrassed" George since he apparently does not believe that science supports 
the LNT model either:  "I also think it is equally irresponsible to apply 
LNT concepts to miniscule environmental doses and calculated horrendous 
collective doses [and corresponding hypothetical cancers] that have little, 
if any, bearing on reality."  Unfortunately such applications may be what the 
LNT model directs "responsible people" to do.  This is exactly what our 
governmental agencies do based on what we scientists tell them.  No one 
would cry "foul" if radiation injury models (that match the scientific data 
fairly well for acute exposures from a few hundred mGy to a few Gy) were 
used only where they are scientifically supported.  But the scientifically 
unsound and unreasonable extrapolations that the LNT model encourages 
perplex and offend many in the radiation protection community.  

	Questioning whether or not chronic radiation injury is stochastic 
or deterministic (described or not described by the LNT model) is not 
tantamount to "malpractice."  Don't the cancers for which we have the 
largest number of cases and amounts of data (leukemia and bone sarcomas) 
show thresholds?  There is no "malpractice" in questioning the scientific 
soundness of the LNT model.  That's what science does:  It Questions!

	No perspective should be censored.  The pubic and our brothers and 
sisters in the radiation protection community should have full access to 
sound science and perspectives.  

	Again, I appreciate George Vargo's contribution to the debate.  I 
encourage everyone to provide meaningful, civil input. 

David S. Gooden