[ RadSafe ] Fwd: French Academie des Sciences
John Jacobus
crispy_bird at yahoo.com
Mon Mar 6 15:28:34 CST 2006
If Ruth was subscribing to RadSafe, she would have
know that this is an old news story that appeared a
year ago. I would hesitate to add that no changes
have been initiated thus far to relax any dosimetry
limits.
--- "Richard L. Hess" <lists at richardhess.com> wrote:
> Ruth Weiner asked me to pass this along to the list
> as she is
> currently not subscribed.
>
> Remember, Ruth is not reading RadSafe currently, so
> if you have any
> replies, please copy her as well as the list. Her
> email address is
> <mailto:ruthweiner at aol.com>ruthweiner at aol.com and
> she is copied on
> this message, so "reply-all" might work.
>
>
============================================================
>
> From: RuthWeiner at aol.com
> Date: Sat, 4 Mar 2006 18:38:24 EST
> Subject: French Academie des Sciences
>
> The Academies of Science and Medicine of France have
> issued a joint
> report, available on the web, that seems to me to
> refuteonce and for
> all the use of the linear non-threshold theory (LNT)
> as a method of
> predicting cancer risk at small (low) doses of
> ionizing radiation,
> and of predicting cancers in a population by
> "micro-doses to
> mega-populations." The joint report is also found
> in M. Tubiana and
> A Aurengo, International Journal of Low Radiation
> v.2, 2005, pp. 1-19.
>
> Some choice quotes from the report:
>
> "...it is highly unlikely [because of very small
> risks] that putative
> carcinogenic risks could be established for such
> doses [< 100 mSv]
> through case control studies or the follow-up of
> cohorts, even for
> several hundred thousands of subjects. The power of
> such
> epidemiological studies would not be sufficient..."
>
> "A linearity observed in a study pooling together
> tumors of all
> types, occurring at all ages, could be only the
> consequence of the
> heterogeneity of the data. It is not legitimate to
> use an empirical
> relationship for assessing the carcinogenic effect
> of low doses."
> [emphasis mine; Bill Field take note]
>
> "...the use of LNT in the low dose or dose rate
> range is not
> consistent with current radiobiological knowledge;
> in particular the
> changes in cellular defense mechanisms...with dose
> and dose rate
> raise questions about its validity for evaluating
> the risks of a few
> dozen mSv." [emphasis mine; a few dozen mSv is a few
> rem]
>
> " the use of a linear no-threshold relationship is
> not justified for
> assessing by extrapolation the risk of low doses
> from observations
> made for doses from 0.2 to 5 Sv since this
> extrapolation relies on
> the concept of constant carcinogenic effect per unit
> dose, which is
> inconsistent with radiobiological data."
>
> Looks like Jim Muckerheide has been vindicated! I
> can remember
> pointing out the extrapolation to my students a
> quarter of a century
> ago, and noting that extrapolation is always dicey.
>
> The report is well-documented. It doesn't pool data,
> it's not a
> mega-study, or ecological study, or whatever, it
> cites different
> researches that have elicited similar phenomena.
>
> All the best.
>
> Ruth
>
> Ruth F. Weiner, Ph. D.
> ruthweiner at aol.com
+++++++++++++++++++
"It is not the job of public-affairs officers to alter, filter or
adjust engineering or scientific material produced by NASA's technical
staff."
MICHAEL D. GRIFFIN, NASA administrator.
-- John
John Jacobus, MS
Certified Health Physicist
e-mail: crispy_bird at yahoo.com
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