[ RadSafe ] Re: AW: Cameron's refutation of "Alara Does Work"

[John Jacobus]

Rainer,
In our government programs, it was directed that
individuals with a history of or a family history of
cancer would be evaluated for work involving radiation
exposure.  This is one reason the incidence of cancers
for shipyard workers refueling and repairing nuclear
ships were less than that for the general population.

You had to be associated with this work to know that. 

--- Rainer.Facius at dlr.de wrote:

> "It was that a doctor giving employment exams might
> unconsciously have
> directed persons of less vigorous health away from
> imagined hazards of
> radiation exposure, to otherwise identical work."
> 
> Howard:
> 
> I have no means to assess the bearing of this
> suggestion in the nuclear
> shipyard context. 
> 
> In my (German) experience an employer offering a
> specific open position
> sends applicants which first of all he sees fit for
> a specific task to a
> physician together with an elementary workplace/job
> description. The
> result of the physician's employment medical is
> conveyed to the employer
> in terms of:
> 
> "Yes or No" the applicant is fit for the specified
> job - period.
> 
> In this setting it is beyond the discretion of the
> physician to direct
> someone to another position and hence here this
> selection bias could be
> ruled out.
> 
> Best Regards, Rainer
> 
> 
> Dr. Rainer Facius
> German Aerospace Center
> Institute of Aerospace Medicine
> Linder Hoehe
> 51147 Koeln
> GERMANY
> Voice: +49 2203 601 3147 or 3150
> FAX:   +49 2203 61970
>  
> 
> ________________________________
> 
> Von: howard long [mailto:hflong at pacbell.net] 
> Gesendet: Mittwoch, 28. Juni 2006 20:05
> An: Facius, Rainer; crispy_bird at yahoo.com;
> jjcohen at prodigy.net;
> mike.bohan at yale.edu; radsafe at radlab.nl
> Betreff: Cameron's refutation of "Alara Does Work" 
> 
> 
> Ranier, your careful review of the Boice commentary
> 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 worker
> selection I have seen
> proposed, was here on Radsafe. It was that a doctor
> giving employment
> exams might unconsciously have directed persons of
> less vigorous 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. I 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
> quality 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 mSv nuclear as compared
> to the non-nuclear
> worker group is the result of bias. 
> 	
> 	He addresses some points of concern without calling
> into
> question the principal quality of the results.
> 	
> 	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 an
> 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 - most
> 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 mechanisms, (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 to
> illness occurring during employment. 
> 	
> 	Although the healthy worker hire effect is
> regularly invoked
> when radioepidemiological studies find massively
> lower cancer
> mortalities (and they usually 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 of employment medicals do have prognostic
> power to select against
> employers more likely to develop cancer than others.
> 
> 	
> 	Regarding the healthy worker survivor effect I have
> so far not
> found quantitative data as to its typical 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 disease 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. 
=== 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
John Jacobus, MS
Certified Health Physicist
e-mail:  crispy_bird at yahoo.com

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