[ RadSafe ] Re: Cameron's refutation of "Alara Does Work"
crispy_bird at yahoo.com
Fri Jun 30 09:04:18 CDT 2006
I did not say a large number were disqualified, but
selection was certainly a criteria. How many would it
take to bias the data?
--- "Muckerheide, Jim (CDA)"
<Jim.Muckerheide at state.ma.us> wrote:
> This isn't right.
> Our discussions with the Navy authorities for worker
> health said that family histories would in fact be a
> basis to preclude a worker from radiation work, but
> that this happened rarely, probably a few dozen
> times (out of 700,000 workers, 108,000 radiation
> They conclude that the few cases would have
> essentially no effect on the statistics.
> Regards Jim Muckerheide
> -----Original Message-----
> From: radsafe-bounces at radlab.nl on behalf of John
> Sent: Thu 6/29/2006 5:41 PM
> To: howard long; Rainer.Facius at dlr.de;
> jjcohen at prodigy.net; mike.bohan at yale.edu;
> radsafe at radlab.nl
> Subject: [ RadSafe ] Re: Cameron's refutation of
> "Alara Does Work"
> Dr. Long,
> As one one worked with medical records at one of the
> Naval shipyards, all workers who were involved with
> radiation exposure would have a screen physical.
> Frequently, those who had relatives with cancers
> be excluded from work involving radiaion.
> Yes, I would think that this would bias the data,
> leading to a sicker cohort of not non-radaition
> workers. That is why the study does not exhibit a
> healthy worker effect, despite the conclusion of
> Rainer, who is neither an epidemiologist nor has
> access to the original data.
> Of course, I doubt that this selection bias was
> into account by Matanoski as she only had the
> but not the directives on worker selection.
> --- howard long <hflong at pacbell.net> wrote:
> > Ranier, your careful review of the Boice
> > on Matanoski's presentation of the vast Nuclear
> > Shipyard Study, confirms my belief that healthy
> > worker effect cannot explain the 3 years of life
> > apparently added by exposure of Gulf Coast workers
> > to 0.5 rem extra.
> > The only credible (although minor) healthy
> > selection I have seen proposed, was here on
> > It was that a doctor giving employment exams might
> > unconsciously have directed persons of less
> > health away from imagined hazards of radiation
> > exposure, to otherwise identical work.
> > Howard Long
> > Rainer.Facius at dlr.de wrote:
> > Dear John:
> > Thank you for providing the Boice Jr. (2001) paper
> > commenting on Matanoski's Nuclear Shipyard Study.
> > took some time to compare his remarks with the
> > original report and therefore my reply is somewhat
> > late.
> > First of all my comparison leads me to conclude,
> > that Boice delivered a very compressed but overall
> > fair summary of Matanoski's report.
> > Secondly, his assessment of the high general
> > of Matanoski's work and report is in line with
> > Sponsler and Camerons's (2005) evaluation.
> > Boice does nowhere claim that the observed
> > significantly lower total mortality of the >= 5
> > nuclear as compared to the non-nuclear worker
> > is the result of bias.
> > He addresses some points of concern without
> > into question the principal quality of the
> > Boice's concentration on leukaemia data - though
> > understandable - is somewhat moot, given the small
> > number of cases and indeed he does not draw any
> > conclusions from discrepancies with his
> > expectations.
> > Regarding race, Boice states "It appears that race
> > was not considered in the analysis which could be
> > important confounder for certain cancers". It is
> > true that Matanoski could not stratify their data
> > with respect to race since the personnel files did
> > not contain this information. It is not true that
> > this confounder was not considered. Mantoniski et
> > al. discuss in quite some length this problem and
> > present their reasons to conclude that their
> > findings would not be seriously affected.
> > An objection sometimes raised against the validity
> > of Matanoski's study is the (apparent) absence of
> > the healthy worker effect frequently seen in
> > occupational studies. Boice also does state this
> > absence without drawing the usual conclusion -
> > appropriately so.
> > Although the literature does differentiate a dozen
> > or so 'healthy worker effects' the bulk of this
> > selection bias can be attributed to two
> > (i) the "healthy worker hire effect" and the
> > "healthy worker survivor effect". The first bias
> > excludes potential workers whose illness prevents
> > them from seeking or finding employment. The
> > corresponding biased SMRs ususally scatter around
> > 0.90 (90%) and hardly ever fall below 0.80.
> > Furthermore this selection bias dilutes within the
> > first years of employment. The "healthy worker
> > survivor effect" results from "differential job
> > migration" either into another less demanding
> > occupation or out of the workforce altogether due
> > illness occurring during employment.
> > Although the healthy worker hire effect is
> > invoked when radioepidemiological studies find
> > massively lower cancer mortalities (and they
> > do) to explain this discrepancy with expectations,
> > this argument rarely exceeds the standing of an ad
> > hoc explanation. So far I never have seen this
> > 'explanation to be offered and then accompanied by
> > an obviously mandatory discussion of which checks
> > employment medicals do have prognostic power to
> > select against employers more likely to develop
> > cancer than others.
> > Regarding the healthy worker survivor effect I
> > so far not found quantitative data as to its
> > size regarding non cancer diseases, but here too
> > such arguments - where needed to explain too low
> > radiogenic cancer mortalities - do never accompany
> > its invocation with a proper discussion of what
> > amount of mortality reduction might reasonably be
> > ascribed to it. Apparently, "anything goes".
> > Furthermore, since cancer is predominantly a
> > of advanced age, the age dependence of the healthy
> > worker survivor effect should be addressed too.
> > Finally, the design of some radioepidemiological
> > studies - such as the studies on European aircrew
> > excluded its influence altogether - which did not
> > prevent some of the investigators to invoke it
> > nevertheless.
> > After all, the Matanoski study does exhibit the
> > healthy worker effect for diseases were you would
> > expect to see it, i.e., for mortality from
> > of circulatory system - the dominant single cause
> > mortality in the age of workforces. The diagram in
> > the attached PDF-file (again available upon
> > if the moderator intercepts it) clearly
> > that the healthy worker effect is there as it
> > properly should be. Regarding its absence from
> > cancer mortality, the diagram reveals enhanced
> > mortality from cancers of the respiratory system
> > the cause. Matanoski's report as well as Boice's
> > discussion appropriately invoke known workplace
> > related agents which cause this enhanced cancer
> > mortality which in turn masks the otherwise
=== message truncated ===
"You get a lot more authority when the workforce doesn't think it's amateur hour on the top floor."
GEN. MICHAEL V. HAYDEN, President Bush's nominee for C.I.A. director.
John Jacobus, MS
Certified Health Physicist
e-mail: crispy_bird at yahoo.com
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