[ RadSafe ] Beta emitters and external risks

[Dale Boyce]

Hi John,

I think you misunderstood me. Unshielded, you get a higher dose rate from 
the positron than the annihilation radiation with F18. People can and have 
been hurt by this. Yes it is a shallow dose, but skin erythema can be pretty 
nasty.

Dale
----- Original Message ----- 
From: "John Jacobus" <crispy_bird at yahoo.com>
To: <daleboyce at charter.net>; <radsafe at radlab.nl>
Sent: Saturday, October 15, 2005 7:58 PM
Subject: Re: [ RadSafe ] Beta emitters and external risks


> Dale,
> You misunderstood what I am look for. If you had a
> drop of a beta emitting radionuclide on a table what
> betas are of concern if you are standing by the table?
> by the way, F-18 and other PET radionuclides emitt
> positron or beta+ particles. Shielding for the
> annihilation photon radiation shields for the positron
> particles.
>
> --- radsafe-bounces at radlab.nl <daleboyce at charter.net>
> wrote:
>> Hi John,
>>
>> I wouldn't ignore skin dose as a radiation hazard.
> At around 9
>> rad/hr/microcurie/cm^2 high energy beta emitters are
> probably the biggest
>> radiation hazard normally encountered in a research
> environment.
>>
>> There are other beta emitters that present a hazard,
> and some come
>> disguised. F-18 is known for its use in PETT with
> the 511 annihilation
>> radiation, but the intermediate energy positrons can
> give one heck of a beta
>> burn (and have in the past) before the gamma dose is
> significant.
>>
>> While low energy beta emitters such as C-14 may
> present a reduced risk due
>> to air and dead layer absorption, one shouldn't
> ignore the potential rish
>> from beta emitters.
>>
>> ----- Original Message ----- 
>> From: "John Jacobus" <crispy_bird at yahoo.com>
>> To: "radsafe" <radsafe at radlab.nl>
>> Sent: Friday, October 14, 2005 4:42 PM
>> Subject: [ RadSafe ] Beta emitters and external
> risks
>>
>>
>> > Question:  Would you say that beta emitters pose
> an
>> > external radiation hazard or risk?  I am not
> consider
>> > skin contamination.
>> >
>> > Are there any (other) beta emitters that you would
>> > consider to be a significant external hazard?
>> >
>> > What is your criteria for this judgement?
>> >
>> > (Background:  I would in a medical research
> facility,
>> > and we require beta shields for work involving
> large,
>> > e.g., 10 mCi/370 MBq, amounts of P-32.  Are there
>> > other beta emitters we should worry about?)
>> >
>> > +++++++++++++++++++
>> > On Oct. 5, 1947, in the first televised White
> House address, President
>> > Truman asked Americans to refrain from eating meat
> on Tuesdays and poultry
>> > on Thursdays to help stockpile grain for starving
> people in Europe.
>> >
>> > -- John
>> > John Jacobus, MS
>> > Certified Health Physicist
>> > e-mail:  crispy_bird at yahoo.com
>> >
>> >
>> >
>> >
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>
> +++++++++++++++++++
> On Oct. 5, 1947, in the first televised White House address, President 
> Truman asked Americans to refrain from eating meat on Tuesdays and poultry 
> on Thursdays to help stockpile grain for starving people in Europe.
>
> -- John
> John Jacobus, MS
> Certified Health Physicist
> e-mail:  crispy_bird at yahoo.com
>
>
>
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