AW: [ RadSafe ] Excess deaths

[Rainer.Facius at dlr.de]

Dale:

Your remark is technically correct, although ever body knows that number of deaths within a given period of time -i.e. death rate - is what we are comparing.

On the other hand, your comment addresses a very important question, i.e., what constitutes a proper measure of 'detriment', in particular if competing risks (or benefits) have to be taken into account too. In such situations the (Healthy) Livespan Lost (HLL) in competing circumstances yields a much more rational criterion to select an optimum set-up, i.e., where HLL attains a minimum - especially if temporal distributions of death rates differ for one or the other of the options you have to select from.

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

-----Ursprüngliche Nachricht-----
Von: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] Im Auftrag von Dale Boyce
Gesendet: Donnerstag, 22. September 2005 02:04
An: Radsafe (E-mail)
Betreff: [ RadSafe ] Excess deaths

Hi All,

There are no "excess deaths" everyone dies. Though I have in the past argued that LNT should not be used to estimate deaths due to radiation exposure, let me pose an argument from a different point of view.

Death due to stochastic effects has a vey long induction time, except perhaps for leukemia and other low occurance rate cancers.  If someone is exposed to 1 Gy or 100 rad, BEIR whatever projects about 4% excess cancers. 

However, pick the mean age of the population.  I could look it up, but let's say it is 35. Then factor in a 30+ year cancer induction period. I know leukemia is much faster, but the rate is also much lower. Then roughly 4% of the people exposed to 1 Gy would contract radiogenic cancer at around age 65, and die some years later (assuming the model).

Now let's apply this to a population of 1 million people. You would see (accepting BEIR for the moment) 40 thousand radiogenic cancers (a number widely reported as expected deaths from Chernobyl). However. the 40,000 need to be multiplied by the fraction of life lost to come up with a realistic "excess death" rate.  So if 1 million were exposed at age 35 to 1 Gy and lost about 10% of their life expectancy, then the lost life expectancy would be about 4000 according to the LNT model.

Moreover, the exposed population was not exposed to this large of a dose.  So the "excess deaths" would be much, much lower.  

I am not trying to make this email a treatise on how to estimate "excess deaths".  I am merely throwing out a framework for discussion on how to realistically interpret BEIR and LNT without tossing it out completely. (Though I might like to).

Dale
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