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Following are my comments on NCRP-136. I'm afraid
that no matter how hard I tried, I was unable to avoid the nasty tone. I would
appreciate your comments on my
comments.
Jerry
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Re: Comments on NCRP Report No. 136, " Evaluation of the Linear-Nonthreshold Model for Ionizing Radiation"
On review of this report, it seems apparent that the objective was to defend the status quo. You have, no doubt, received comments from other reviewers criticizing your summary dismissal of the plethora of scientific publications that support the existence of a dose threshold and the validity of hormesis. In the unlikely event that you are unaware of this body of scientific evidence, I would gladly supply a list of references. The main point I would like to make in this letter is to urge you to consider the total spectrum of ionizing radiation effects on biological systems, primarily humans in assessing the net overall health consequences to dose recipients. As stated in NCRP-136, the study focused on those effects related to chromosome aberration (carcinogenicity, etc). While such effects are certainly important, they may not be of overriding impact at all dose levels and/or for all organs and tissue systems. For example, there is a considerable body of evidence that ionizing radiation can have a stimulatory affect upon the immune response system. Again, if you're not familiar with this body of knowledge I would be happy to supply a list of references. It is noted, for example, that the scientific committee preparing NCRP-136 included no immunologists. Perhaps inclusion of this body of expertise might have significantly influenced the conclusions of the report. Perhaps what is needed in the evaluation of radiation effects is a new paradigm. Rather than perpetuating an approach that focuses only those effects involving chromosome aberration, it might be in the best interests of public health to consider the complete spectrum of radiation effects that could result from radiation exposure. It is likely that ionizing radiation could simultaneously produce a multiplicity of effects on biological systems, some of which may be harmful, while others may concurrently be beneficial in nature. Determination of the net consequence should require a quantitative consideration and evaluation of all such effects. Depending upon the dose level, the net consequence might be either detrimental or beneficial in nature. Indeed, it is conceivable that the same radiation exposure that causes DNA alterations, could simultaneously enhance the body's ability to cope with and overcome such effects as well as those caused by other unrelated disease processes. Should you be interested, I would be happy to provide any further information that you may request to support the arguments made in this letter. Thank you for your consideration.
Sincerely, Jerry J. Cohen |