Danger from Am-241 compared to other everyday products

["Franz Schoenhofer" <franz.schoenhofer@CHELLO.AT>]

-----Ursprüngliche Nachricht-----

Von: Dimiter Popoff <tgi@cit.bg>

An: radsafe@list.vanderbilt.edu <radsafe@list.vanderbilt.edu>

Datum: Donnerstag, 20. Juni 2002 21:14

Betreff: Re: Rad Sources for Workshops





>

>>As far as I know, the americium is fixed at the surface of a ceramic

matrix.

>>How to ingest it without breaking your teeth?

>

>I have seen one smoke-detector 241Am source which is somewhow built

>at the bottom of something like a brass well (so the source would

>be directed).

> The whole thing had 10-12 mm outside diameter, and ended with a screw

>at the rear (if the opening for the source is the front) side.

>I suppose one could swallow it - but then I imagine anyone wanting

>to swallow such a piece of metal would have much bigger, non-radiation

>related problems...

> However, the source seemed not so weak; it was doing a 40 or 50 kCps

>gamma through the Be window of a 15% HPGe detector...



----------------------------------------------------



Dimiter,



If it really was Am-241 I would like to mention, that it is not the count

rate which is of importance, but the dose delivered to somebody, who handles

these devices. The Am-241 gammas are of rather low energy - I remember that

we measured it on the Mururoa atoll with thin NaI(Tl) detectors because of

the low energy in the field. Therefore the dose conversion factors are

probably very low for external irradiation. I do not have my scientific

literature at home, so I cannot do any calculations, but probably other

RADSAFErs will be able to easily convert the countrate on your Ge-detector

to a dose for contact or in a distance of 1 m. I bet it will in both cases

be extremely low.



The next point is the possible misuse of the source, by either swallowing it

or scratching the surface and use the scratch off instead of salt and pepper

on a T-bone steak.... I read on postings, that it is Americium-Oxide, which

is fused to a ceramic substrate. Scenario #1: The source is swallowed. Not

taking into consideration the problems of swallowing something of that size,

I do not expect the Americium-Oxide to be readily dissolved - no doubt the

chemical form has been chosen to make the Am-241 insoluble and not

removable. The source would pass through relatively fast and no Am-241 will

be dissolved and therefore not transported to any critical organ. The only

contribution to the dose could be the weak gamma-radiation. I hardly dare to

mention that Andrew McEwan would easily answer that question, because he

would believe, that I volunteered him...... I would be happy if you, Andrew,

could comment.



Scenario #2: Some naughty child or an idiotic adult scratches the surface of

the foil, the ceramic cylinder or whereever the Am-241 is attached to and

ingests it. So what???? Is this the normal use of a smoke detector? We have

in our standards and in legislation the technical term "appropriate use of

the source for the purposes, which it is intended and has been dedicated

for". The Am-241 in a smoke detector is not intended to be scratched of and

to be ingested. The smoke detector is not even designed to be swallowed. If

the smoke detector is kept in a place, where children can take hold of it,

disassemble it and swallow the ceramic disc - then it is the problem of the

custodians - parents or nurses or au-pair girls - and not of the producer of

this device. Moreover the dose would be negligible. Furthermore I cannot

imagine that somebody would scratch the Am-compound off and use it as a

spice - if he or she does it, nobody except these idiots can be held

responsible for it.



Go to a supermarket. Buy a few kilos of salt, go home and "eat" it. You will

die. Is the producer to be held responsible? Buy a package of insect killing

tablets, eat them. You will die. Again: is the producer responsible? Buy a

few bottles of whisky, vodka or else and drink it within a short time - you

will die.



Why are people - especially radiation protection professionals - always so

eager to point out the very outstanding and special hazard of radioactive

material? Why is its use in everyday products so severely regulated though

everyday products which can easily kill people if used in excess quantities

are sold everywhere without restriction? We are surrounded by dangers - car

accidents, pollutants, chemicals - also outside supermarkets, but what

obviously counts are scenarios like the "dirty bomb".



Can anybody enlighten me, what the difference is, that makes smoke detectors

more hazardous than insecticides, pesticides etc.?



Regards,



Franz









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