Re: LNT, regs and lives

["Bjorn Cedervall" <bcradsafers@hotmail.com>]

3-4 days ago I commented the LNT issue partly from the molecular biology 
perspective. Part of my text was about trivial doses. I was surprised to 
note that all emotions came with the SI discussion whereas there were few if 
any comments to my LNT text.

Just thought I could add one more idea - a suggested definition level for 
"trivial doses": That which is below 0.2 mSv (=20 mrem) which is what you 
annually get from your K 40 level. The idea is simple - most of us know that 
the K 40 is there - and we all know that this normal level of radioactivity 
never (or rarely?) makes people afraid of being close to one another (which 
causes even lower - but mutual irradiations). Take an extreme case: Five 
people sleeping close to one another 8 hours per day - less than 0.1 mSv 
would be obtained (should put some five cylinders into a program...) - 
obviously still trivial (from the radioactivity aspect). Alternatively one 
could include the cosmic and ground contributions also (except radon) and 
put it at 1 mSv (100 mrem) - still something we don't worry about in daily 
life. Delay your "production" of children one - year: This is typically 2 to 
5 extra mSv to your gonad cells. It may not be judged "trivial" for some 
finer genetic analysis but most people wouldn't think much about this. 
Somewhere in the approximate range 0.1 mSv (10 mrem) to 1 mSv (=100 mrem, or 
perhaps even more) is probably close to where most "informed" people would 
agree that we are at trivial levels.

Below these levels we could just leave many forms of administrative 
exercises and let the analysis be performed by those who for theoretical 
reasons are working with single hits on chromosomes etc. The trivial 
estimated/calculated doses may be interesting to follow from a trend 
perspective or perhaps for decision making (chosing between two 
alternatives). What seems "somewhat crazy" is when you are down in the 
background variation and start counting number cancer cases. Statistically 
you could probably have a few real cases if enough of years and people 
(billions) are allowed but that must be put into a perspective of all risks 
(I am on my way to some questionable American fast food).

We have by the way (ref. some so called OSPAR document is supposed to treat 
this) some people who are advocating zero Bq-levels of of radionuclides like 
Co-60, Zn-65, Cs-137. I was therefore today asked to figure out what is 
meant by zero. I see two approaches: 1. Detection limit (measurement) of the 
best accumulating organism (Fucus, kelp (??) etc?) 2. Some statistical 
description relating to the dose rate variations in nature.

These are my own ideas that may not necessarily coincide with those by 
others.

Bjorn Cedervall,    bcradsafers@hotmail.com

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