>A few thoughts (opinion) in response to Al Tschaeche's latest posting
>and this thread in general.
> If we set a purely threshold limit, the public, suspicious of
>government, scientists, institutions, etc., will ask. What happens
>below the threshold? How do you know? Prove it? For those of us
>(i.e., those scientifically knowledgeable) who are convinced that
>there are no, or possibly beneficial, effects below 5 rem/yr, the
>answers are: Nothing bad. I'm convinced as a scientist. Citations
>to the literature. But some of us (same definition) can only say "I
>don't know - but I'm convinced the bad effect, if any, is small"
>(citations to the literature). Alas, many in the public (e.g., those
>who play the lottery because "someone has to win; it could be me")
>will not be convinced. "Some scientists say there might be a bad
>effect". To the risk averse this translates to: "There may be a bad
>effect; someone has to be damaged; it could be me; I don't want
>that".
> If the LNT is seen as giving an upper limit on risk, I think it
>can be helpful in at least defining to the public how "small" the
>largest "small" effect is. If we leave people with the idea that
>the effects of radiation, a menace undetectable to the senses, are
>"unknown", we leave the door open for all sorts of monsters to enter.
> By putting an upper limit on the risk with the LNT assumption we
>can at least hope to stop the idea that there may be a major
>undiscovered effect lurking at very low doses. (There are people who
>believe that very dilute medicines are more powerful than
>concentrated ones!).
> In short, at the present time (convince me otherwise), I think
>the LNT is useful in 2 contexts: standards setting and establishing
>an upper limit on quantified risk. In other contexts, I think it is
>more than useless; it is misleading, counterproductive, and all
>things Al said about its influencing the demise of the rad world as
>we know it. Quantitative risks derived from the LNT should NOT be
>used in risk assessments that purport to show what the actual effects
>of some radiation-producing action on actual people are, have been,
>or will be.
> As HPs and rad scientists, we should not let simplistic use be
>made of risk extrapolations by those who put together NEPA
>statements, PRAs, and similar public documents. Make sure every risk
>assessment has uncertainties stated. Make it clear that the LNT
>extrapolation is an upper limit only; the actual value is somewhere
>below that; it may be zero, it may be an itsy bitsy (de minimis)
>detriment; it may be a benefit (also small).
> Until we can get a better handle on the quantitative detriment
>of low doses or prove to a reasonably high degree of certainty that
>low doses have a zero or beneficial effect, I suggest we put our
>efforts into ensuring that the right risk assessments be used in the
>right manner, not in declaring one way of estimating risk verboten.
>And maybe, just maybe, the public will begin to understand a little
>better.
> Don't you think that if the entire HP community, nuclear
>industry, and regulatory agencies came out today for a threshold at 5
>rem per year and a prohibition on the use of the LNT, many in the
>public would interpret it, not as the triumph of reasonableness but
>as another conspiracy of the power elite to make money at the expense
>of the powerless citizen, exposed to invisible rays?
>
>Only the opinion of J. P. Davis
>joyced@dnfsb.gov
Joyce;
I have to agree that you have hit it on the head.
Marvin Goldman
mgoldman@ucdavis.edu