AW: [ RadSafe ] query

[Rainer.Facius at dlr.de]

Mike:

"[...] BEIR group's defense of their work at the HPS meeting [...] was pretty reasonable, given what they were working with in the way of data and what their charge [...] were"

As an afterthought to my previous comment I believe your observation above spells out the probably most important reason for the messy outcome of their mission. The entanglement of scientific, protective/regulatory, liability/political assignments as set out by BEIR VII-1's mandate (and as copied below) was bound to spawn the mixed assortment that resulted. The French were wise to confine themselves to what their expertise was, science, and the NAS might have fared better if they had split the different issues and assigned them to different, independent committees, each fully and solely responsible for their genuine field of expertise.

"[...] I see no evidence in either case of a badly biased approach or of scientific misconduct [...]."(from your subsequent note)

Of course there is personal judgement involved, yet I can see no valid reason given for essentially discarding - as they did - all worker studies (several important of their own BTW) which clearly cry null-effect in the dose ranges studied and to rely once more only on the - for chronic exposures - 'irrelevant' ATB survivor data. When there is no valid reason given for the dismissal (in the final analysis) of relevant data you might choose other qualifiers to characterise this decision but I don't consider it improper to call it scientific misconduct.

Best regards, Rainer

/*************************************************************************************************************/
(BEIRV II-1), Health Effects of Exposure to Low Levels of Ionizing Radiations: Time for Reassessment?
National Academy Press, Washington, 1998

p. 2-4:

The committee recommends that the individuals responsible for the proposed phase-2 study 

*	Include a comprehensive review of all relevant epidemiologic data related to low-LET (low linear energy transfer), i.e. sparsely ionizing, radiation. 


*	Define and establish principles on which quantitative analyses can be based, including requirements for epidemiologic data and cohort characteristics. In this respect, the committee should consider biologic factors (such as the dose and dose-rate effectiveness factor, relative biologic effectiveness, genomic instability, and adaptive responses) and appropriate methods to develop etiologic models (favoring simple as opposed to complex models), estimate population detriment and attribute causation in specific cases. 

*	Assess the current status and relevance to risk models of biologic data and models of carcinogenesis. This should include a critical assessment of all data that might affect the shape of the dose-response curve at low doses, in particular, evidence of thresholds or the lack thereof in dose-response relationships and the influence of adaptive responses and radiation hormesis.

*	Consider potential target cells and problems that might exist in determining dose to the target cell.

*	Consider any recent evidence regarding genetic effects not related to cancer. Any such data, even if obtained from high radiation exposures or at high dose rates, should be considered.

With respect to modeling the committee recommends that the individuals responsible for the proposed phase-2 study 

*	Develop appropriate risk models for major cancer types and other outcomes including benign disease and genetic effects. Specifically, the responsible committee should develop models appropriate for use in future development of probability-of-causation tables and should consider the fitting of purely empirical models to original data from studies or combined studies, the fitting of purely empirical models with meta-analytic techniques, and the fitting of semiempirical biology-based models to epidemiologic data. 

*	Provide examples of specific risk calculations based on the risk models and explain the appropriate use of the models. 

*	Describe and define the limitations and uncertainties of the risk models and their results. The committee conducting the proposed phase-2 study should be directed to develop best-estimate models for purposes of risk assessments as opposed to developing conservative models for purposes of radiation protection.

*	Discuss the role and effect of modifying factors, including host (such as individual susceptibility and variability, age and sex), environment (high background radiation exposure), and lifestyle (such as alcohol and cigarette consumption). 

*	Identify critical gaps in knowledge that should be filled by future research. 

To accomplish the charge suggested here, the membership of the committee responsible for the proposed BEIR VII phase-2 study will require expertise in epidemiology, biostatistics, radiation physics and dosimetry, molecular biology, risk assessment and communication, cancer modeling, animal and cellular radiation biology, somatic cell genetics, cell-cycle regulation and apoptosis, and the causation and repair of DNA damage induced by ionizing radiation. The committee recommends that the experts chosen have adequate resources and access for data for the computing, statistical analyses and modeling required to complete the study. A major goal of the BEIR VII phase-2 study will be to better quantify and characterize the uncertainties associated with risk estimates and to produce the most realistic estimates of uncertainties. 
/*************************************************************************************************************/

-----Ursprüngliche Nachricht-----
Von: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] Im Auftrag von Stabin, Michael
Gesendet: Mittwoch, 17. August 2005 17:59
An: Bernard Cohen; RadiatSafety
Betreff: RE: [ RadSafe ] query

<...> 
I listened to the BEIR group's defense of their work at the HPS meeting, and it was pretty reasonable, given what they were working with in the way of data and what their charge and audience were.
<...>

Mike

Michael G. Stabin, PhD, CHP
Assistant Professor of Radiology and Radiological Sciences Department of Radiology and Radiological Sciences Vanderbilt University
1161 21st Avenue South
Nashville, TN 37232-2675
Phone (615) 343-0068
Fax   (615) 322-3764
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e-mail     michael.g.stabin at vanderbilt.edu 
internet   www.doseinfo-radar.com