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Fwd: Re: WIPP shipment through Albq. NM
Hi, John,
I've been following this discussion with interest and I must say that I would
feel much better if I were told the following. I believe this better presents
all the facts as we know it than just using NCRP 116.
"The conservative, worst-case assessment of risk for these CT scans, based on
NCRP 116 is that your risk of dying from cancer will increase from 25% to
25.15% (or whatever based on number of REMs (3?) received), however there is
also evidence that the projections contained in NCRP 116 overstate the risk of
increased cancer.
"Studies of people who live in areas with higher background radiation (incluing
Denver and the mountain regions above Denver) do not seem to support the
extrapolation embodied in NCRP 116, and some researchers suggest that low-level
radiation might actually be beneficial.
"Therefore, based on the conservative government-required calculation, your
worst-case risk is the increase from 25% to 25.15%. However, since this
calculation is based on assumptions that are extremely conservative, this
increase is an upper limit, a regulatory convenience.
"Informed professionals disagree on what the level of risk is, but all agree
that it is not worse than this number. Some think that the amount of radiation
you have received could even be beneficial."
I think this kind of education is important and what Barbara and Ruth are
talking about.
Cheers,
Richard
--
Richard L. Hess
http://www.richardhess.com/
Quoting John Jacobus <crispy_bird@YAHOO.COM>:
> Barbara,
> I appreciate your commets, and could add some
> additional comments. However, I would like to comment
> on the use of the LNT
>
> First, it is not a scientific law, or theory. It is a
> regulatory tool. However, like a hammer, people get
> hurt using it. In the regulatory arena, we use it to
> make projections of risk below known values to
> evaluate risk, project costs of compliance, etc.
> Extrapolation of data is not unknown in science. The
> problem is, as you say, we are do not say what the
> limitations are. Figuratively, we do not discuss the
> error bars, what we don't know. As a consequence, the
> LNT has been taken and used as a club against us. The
> reality is we do not unknow low-level risks; the
> preception is that we do. I am sure reports on the
> transporaton of TRU waste consider risk as some low
> number. The preception is that these estimates,
> extrapolations are real, i.e., that accidents will
> happen. However, laws and policy makers require risk
> estimations to be made. If not the LNT, then what?
> Still, my feeling, which I believe is like yours, is
> that we do not articulate the unknown.
>
> I frequently field questions such as "I have had xx
> number of CT scans. What is my chance of getting
> cancer." I will first figure a risk value based on
> 0.05% additional cancers per 1 rem exposure, using
> NCRP 116. Then I will put it prespective, which is
> that the accepted cancer rate is 25%, and that even
> this number can change. I also try to explain that
> the value is itself an estimate based on a population,
> and that we cannot say what an individual persons risk
> is.
>
> I do not know if this eases the person's concerns, but
> I feel that I have failed if I do present the all the
> facts. I took me a while to figure out this approach.
> And I do not know if it really works. But as an
> "expert" I try to lay out all the facts and unknowns.
> Of course, the people I deal with do not have an
> agenda, just valid concerns and questions.
>
>
----- End forwarded message -----
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