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Re: Crows

In a message dated 10/30/01 4:46:03 PM Mountain Standard Time, loc@ICX.NET writes:


If the
scientific evidence against LNT and favoring hormesis is sufficiently
strong, eventually the political establishment will accept the
scientific truth.


"Eventually" is open-ended.  Let's separate the threshold phenomenon from hormesis, for a moment.  There has never been evidence for a "no threshold" theory of radiation damage in organisms (as distinct from cells), because essentially all organisms can have some DNA repair.  Nor has there been evidence for a strictly linear relationship between dose and cancer incidence, and such a relationship would be difficult to establish anyway.  The LNT was a convenient conservative estimate at a time when relatively little was known about the relationship.

In the past half-century, many of those exposed to putatively carcinogenic doses of ionizing radiation have lived out their life spans, and we can look at cancer incidence in these populations.  Evidence for existence of a threshold continues to accumulate, and no evidence has surfaced for "no threshold."  Linearity is probably as valid as any assumption about the relationship, because of scatter in the data, but linearity has nothing to do with existence or non-existence of a threshold (CO has a linear dose response curve with a very clear threshold).

Why aren't the regulators buying this?  Because (a) they apparently do not think scientifically, (b) they seem to be scared to death of activist opinion, which they call "public opinion," and (c) the decisions are made by political appointees, who are generally selected on the basis of campaign contributions or long-standing support.  This is true for both political parties.  About 25 years ago EPA had excellent evidence for making the ozone ambient air standard more lenient, and they immediately got slapped down.

I believe that as a scientific community we have to take a stand on behalf of the evidence and rewrite regulations so that they recognize at least what is below a threshold.

Just my opinion.

"Of course I have a closed mind, but at least it has something in it worth closing on"  -- Marcia Davenport

Ruth Weiner, Ph. D.
ruthweiner@aol.com