AW: [ RadSafe ] Re:Reasonable risk?

Rainer.Facius at Rainer.Facius at
Fri Apr 21 06:45:58 CDT 2006

Maury&Dog (&all):

In a world where there is no free lunch, the ALARA principle is indeed an 'ivory tower' concept, obviously and inherently unfit to address real world challenges unless verifiable criteria are specified for what has to be considered an infringement. Apart from the fact that among any two stake holders you will find at least three contradictory notions of what they do consider "reasonable" in any given circumstance, the principle defect of this concept is that it endeavours to materialize infinity in a finite world.

Scientists confronted more closely with the real world than some of the leading contemporary radiation or environmental protectionists, such as applied economists, half a century ago developed the theory and tools of (linear) optimization theory which in addition to technological progress proved most effective in stimulating and guiding economic and hence social progress - the latter being irresolvabley dependent on the former. The difference between the two approaches - one to strive for an utopian (not of this world) goal (zero exposure), the other to realize a finite optimum within the often very finite constraints imposed by natural law and limited human capabilities and resources requires, however, that a NUMERICAL criterion is specified and adopted whose optimum is to be sought and put into practice. 

The strange persistency of this ALARA 'principle' in radiation protection presumably is due to the fact that after all the detriment from chronic low-dose radiation exposures (in contrast to genuine radiation accidents!) is a fictitious rather than a real world phenomenon. Nevertheless, its mindless application creates very real consequences. A case in point was the application of the ALARA principle of an important European airline to the October-November 2003 solar particle events. Presumably under pressure from its trade unions this airline decided to reduce the cruising altitudes of their planes in order to "reasonably lower" the putative added 'cosmic' radiation exposure of their crew. In the end, all they achieved was to literally burn heaps of additionally required kerosene dollars with the associated increase in environmental pollution. 

In space, to the contrary, radiation hazards - in particular from long term missions outside the geomagnetic shield - are doubtlessly a very real phenomenon. Yet, these radiation hazards have to be evaluated with respect to the many competing and quite substantial technical and medical hazards associated with such an undertaking. The ALARA principle is patently useless or even counterproductive in guiding habitat shielding and mission design for such an assignment. A criterion capable to meet this challenge is the expected "healthy lifespan lost" (HLL) due to a given mission, i.e., the number of years by which the normal healthy lifespan of a participant has been cut down due to his participation. Among the 'countless' positively and negatively correlated factors which determine the HLL for a given mission, that combination of factors has to be sought for which the HLL attains a minimum value. Provided that the job was done properly, this minimum would be the best that can be achieved in the real world. If this were deemed unacceptable, then the constraints would have to be relaxed by either lowering the objectives or by augmenting the allocated resources. 

The advantage of this HLL criterion with regard to the present discussion is that (apart from steering clear from the scorned attachment of prize tags to human life) it explicitly lays open the interdependence in the real world - in contrast to the utopian world of the ALARA proponents - between goals to be achieved and the necessary resources enforced for their achievement by the 'laws of nature' (not of man!).

It would be interesting to arrive at an estimate of how many years of HLL might have been spared if the public (tax payers) money wasted for ridiculous ALARA activities had been invested instead into funding of e.g. medical research on countermeasures against the many real health risks which still lead to premature termination of human lives.

Kind regards, Rainer


Von: radsafe-bounces at im Auftrag von Maury Siskel
Gesendet: Fr 21.04.2006 03:55
An: jjcohen at
Cc: Michael Bohan; Flanigan,Floyd; radsafe at
Betreff: Re: [ RadSafe ] Re:Reasonable risk?

It seems to me and Dog that the meanings of any rule, law, or regulation
containing the criterion "reasonable" is just as ludicrous and those
stipulating "zero" tolerance,  defects., or "total" safety, and so on.
All of these value judgments are synonyms for zero judgment,
responsibility, and authority. Attempts to make formal use of such terms
are abdications of responsibility and authority. This seems so obvious
that it is a continuing source of amazement that any society remains
willing to employ them. Similarly, those terms place unreasonable
burdens on the selection or inheritance of leadership. Human animals
just are not built this way.

At least one improved approach seems to lie in adopting quantitative
rules and then accept the credit or blame as it comes -- and then modify
the rules as the accumulation of evidence progresses.

But I'm not confident that human animals show much promise for this
approach either -- surely it is better to try, however, than just  fold
to "reasonable" and whatever that means to those happening to possess
power at the moment.

Best regards,

jjcohen at wrote:

>    All of my decisions and actions are reasonable. I am not so sure about
>yours-- and, other peoples decisions have been really bad.
>    The point I have tried to make in this discussion is that  ALARA is a
>basically absurd concept, because what is or isn't reasonable is largely in
>the eye of the beholder. Consequently, ALARA decisions can, and have been
>arbitrary in nature
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