[ RadSafe ] Po-210 Lethal dose

Tue Nov 28 09:04:23 CST 2006

As you said, the problems in the argument are the dose coefficients. 

They are given in Sv/Bq, so they are referred just to stochastic effects. These coefficients are derived taken into account the total integrated dose in the total person life (considered 50 years for every adult), so they are not applicable to acute irradiation effects.

When referring to non-stochastic effects you should use Gy/Bq.

For external irradiation the LD50/30 (it is to say, lethal dose for 50% of the population in 30 days) is around 3-4 Gy, but for the treated case, as the latent period has been of around 10 days and probably a 100% of the population would die at the received dose, it may probably exceed 10-11 Gy (whole body dose).

Was also missed chemical form considerations. Probably polonium was organically bounded in a stable form. May be polonium citrate.

Considering a constant (this is aproximately correct as the half life is long enough) irradiation and a complete absortion of the alfa emmissions, can be calculated an aproximate needed mass of 20 micrograms of polonium citrate in order to reach 10 Gy in 10 days for a 70 kg adult person. If the content of 210Po in your polonium citrate solution is a 0.1%, you should use around 20 mg of your solution (not too bad).

I'm sorry cause my bad english.

-----Mensaje original-----
De: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] En nombre de Bjorn Cedervall
Enviado el: martes, 28 de noviembre de 2006 14:20
Para: radsafe at radlab.nl
Asunto: RE: [ RadSafe ] Po-210 Lethal dose

>I read in some account the amount of 5 Gy for this ex-spy which is 
>probably not based on anything and is a wild guess.  But for arguments 
>sake...  Since Table 1 of Appendix B 10 CFR 20 shows the oral ingestion 
>ALI (daily) as 3 uCi for Po-210, that suggests he would need to have 
>swallowed approximately 3 mCi of Po-210 to get that dose.  My question:
>Is that a legitimate way to ball park the ingestion amount? Or is there 
>a more appropriate way to do it.  Thanks.

I am definitely not the expert to come down with a definite response but had a few considerations which may be relevant - please comment if they do not belong here:

1. Specific activity of Po-210: 1.67 x 10E14 Bq/g (or 1.67 x 10E8 Bq/microgram).

2. Deadly amount, using effective dose coefficient (ICRP 67, 1993):
1.2 x 10E-6 Sv/Bq (for all organs summed up, acute intake).
Is this factor relevant for non-stochastic effects?

Say 10 Sv as a dose: 10/1.2x10E-6 = about 10E7 Bq.

Am I correct this far? If so a division is all that remains (??).
Don't we land in a region of less than a microgram then?

My personal initiative,

Bjorn Cedervall    bcradsafers at hotmail.com

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