Low Dose Risk

["ERIC GOLDIN"<goldinem@songs.sce.com>]

     Regarding the Federal Report 13 discussion of risk at low doses, 
     recall the once-upon-a-time organization, Committee on 
     Interagency Radiation Research and Policy Coordination?  CIRRPC 
     (pronounced chirp-ick), which represented EPA as well as FEMA, 
     NRC, NSF, OMB and just about every cabinet-level agency in the 
     U.S. government, stated in Science Panel Report No. 9 (December, 
     1992) "Use of BEIR V and UNSCEAR 1988 in Radiation Risk 
     Assessment":
     
     "The Subpanel also developed a statement on the scientific 
     uncertainty associated with applying the nominal risk estimates 
     for the reference dose of 0.1 Gy (10 rad) to the absorbed doses 
     well below 0.1 Gy (10 rad) that are often encountered in 
     practice.  The Subpanel recommends that a statement accompany the 
     numerical estimates of cancer deaths resulting from such risk 
     assessments whenever the numerical estimates are provided for use 
     in a decision-making process or for release as public 
     information.  An example of such a statement is:
     
          The numerical estimate of cancer deaths presented was        
       obtained by the practice of linear extrapolation from the       
       nominal risk estimate for lifetime total cancer mortality at    
       0.1 Gy (10 rad).  Other methods of extrapolation to the         
       low-dose region could yield higher or lower numerical estimates 
       of cancer deaths. Studies of human populations exposed at low   
       doses are inadequate to demonstrate the actual level of risk.   
       There is scientific uncertainty about cancer risk in the        
       low-dose region below the range of epidemiological observation, 
       and the possibility of no risk cannot be excluded."
     
     The CIRRPC report footnote for this discussion (on page 5) 
     included a reference to the BEIR V commentary that also stated 
     that the "lower limit of the range of uncertainty in the risk 
     estimates extends to zero."  {see BEIR V, page 181}
     
     CIRRPC concluded with an admonition that "Federal agencies 
     include such a statement PROMINENTLY with their risk 
     assessments."  {Emphasis added}
     
     If nothing else, comments on Report 13 should stress that EPA 
     include such a statement.  IMHO anyway.  Ah, where did 
     interagency policy coordination go?
     
     Eric Goldin, CHP
     <goldinem@songs.sce.com>