Re: What to do ? ? ?

[Kai Kaletsch <info@eic.nu>]

Richard,



> ...At this point I have a stockpile of KI tablets (I'm not planning on

taking

> them any time soon), fiber dust masks (probably useless, but if wet MIGHT

> plate out heavier alpha particles to avoid them getting into your lungs

and

> decaying in there for a while), ...



Alpha particles don't decay, they capture electrons and become helium atoms.

You probably mean alpha emitters. It is the chemical properties and physical

form of the radionuclides that is important, not their weight. Noble gas

will pass through the filters, but most particulates would get caught.

Problem with the cheap disposable dust masks is that they usually do not

provide a good seal against your face and the air goes around them.



> If I recall correctly 0.5 REM/year is the guideline for the average

> population??? What would you consider a guideline for worrying? Getting

all

> of that in a week? One day? 10x that in a week? Rough ideas would be

helpful.



There is a difference between worrying and being aware. I have my

GammaMaster wristwatch set to alarm at 0.6 µSv/h (60 µRem/h). If it ever

alarms, I will investigate to see where the radiation is coming from. Then

I'll decide if I should worry or not.



Obviously, if you believe in a threshold for radiation effects or if you

believe in hormesis, you don't worry about radiation until the threshold or

hormesis level is exceeded. The "official" risk model is still Linear No

Threshold (LNT), which says every little bit of radiation carries some risk.

I don't think a lot of people really believe in this as the true response

curve, but quite a few people think it is an OK operational model, which can

be used to make cautious decisions.



Under this model, you are supposed to spend ~$100.00 to prevent 1 mSv of

radiation exposure. This is based on the hypothetical risk 1 mSv of exposure

carries and typical expenditures we make to reduce risk in other situations

(e.g. installing seat belts in cars, treating drinking water, inspecting

food...). This model tells you that it would be prudent to accept $ 500.00

worth of inconvenience to avoid 5 mSv (0.5 Rem) of exposure. In other words,

if it takes more that $500.00 to eliminate the 5 mSv, you could probably

spend the $ 500.00 in a different way (e.g. put new tires on your car,

choose fire proof building materials for your house ..) and get a bigger

reduction in risk.



Hope this helps. For some people the $ value puts risk in perspective, to

others its meaningless.



The guidance for emergency response personnel is to take up to 100 mSv

protecting major property and up to 250 mSv protecting lives. I guess that

is considered an acceptable risk in a risky profession.



Regards,

Kai



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