[ RadSafe ] Re: How much of RSH still exists?

[Ludwig E. Feinendegen]

Dear Rainer:

Many thanks!  As you asid, the real numbers - even if they come - do not promise a change in the authors conclusion.   -  It is interesting that two recent papers: 

Atkinson WD, Law DV, Bromley KJ, Inskip HM.   Mortality of employees of the United Kingdom Atomic Energy Authority, 1946-97.  

Occup Environm Med  2004; 61: 577-585



and 



Zablotska LB, Ashmore JP, Jowe GR.   Analysis of mortality among Canadian nuclear power industry workers after chronic low-dose exposure to ionizing 

radiation.  

Radiat Res  2004; 161: 633-641



not only contradict the Cardis et al. conclusion but find a reduction of cancer incidence in the low-dose exposed groups (see attachment). 

All the best,
Ludwig


  ----- Original Message ----- 
  From: Rainer.Facius at dlr.de 
  To: feinendegen at gmx.net ; higsond at bigpond.net.au ; rad-sci-l at WPI.EDU ; radsafe at radlab.nl 
  Sent: Wednesday, September 21, 2005 12:47 PM
  Subject: AW: How much of RSH still exists?


  Ludwig:

   

  You most appropriately remark "this paper . does not give the cancer incidences in the various dose groups."

   

  The Cardis BMJ 2005 paper is essentially an extended abstract if you relate it to the amount of data that it comprises. 

   

  Unfortunately, in some recent epidemiologic studies the journal editors allowed the authors to present only the values of fit parameters and model statistics without the tables displaying the raw numbers. In all larger worker studies where these raw numbers had been presented, i.e., in each dose category the number of observed and the number of expected cases of a given cancer (or disease), these data are perfectly compatible with a "no-effect" model in the dose ranges given. 

   

  Hopefully, the journal editors where by the end of this or the beginning of the next year the full papers of the Cardis study will be published will insist that these raw data are presented too. Otherwise it will be impossible to critically evaluate these papers, which in turn is equivalent to these papers being a wasted effort - to print them and to read them.

   

  It might be well worth the effort that those who know where these papers have been submitted contact the journal editors with respect to the presentation of raw data.

   

  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: owner-rad-sci-l at WPI.EDU [mailto:owner-rad-sci-l at WPI.EDU] Im Auftrag von Ludwig E. Feinendegen
  Gesendet: Montag, 19. September 2005 12:52
  An: Don Higson; Jim Muckerheide, RSH; Stanley E. Logan
  Betreff: Re: How much of RSH still exists?


  Friends:

  The Cardis et al paper is impresive becuse it handles large numbers. However, the analysis of the data in this paper applies a linear dose-risk function and does not give the cancer incidences in the various dose groups. The enormous spread of calculated risk coefficients in the various cohorts in addition to the application of a linear function in the data analysis limits the power of this paper to address the low-dose cancer risk.

  Some quotations from the Cardis et al.paper: 
  A total of 24 158 (5.9%) people were known to have died during the study period: 6519 from cancers other than leukaemia and 196 from leukaemia excluding chronic lymphocytic leukaemia. --- The distribution of  recorded doses was skewed (fig 1). Ninety per cent of workers received cumulative doses < 50 mSv and less than 0.1% received cumulative doses > 500 mSv. --- Analyses were based on a linear relative risk Poisson regression model, in which the relative risk is of the form 1+Z, where Z is the cumulative dose equivalent in Sv and is the excess relative risk per Sv; ---  Attributable risks were estimated by multiplying the excess relative risks by the average dose in the cohort. ---  Only when we excluded Canada was the excess relative risk no longer significantly different from zero (0.58, - 0.22 to 1.55).--- Overall, on the basis of our central risk estimates, we estimate that 1-2% of deaths from cancer (including leukaemia) among workers in this cohort may be attributable to radiation.

  Best regards,

  Ludwig