[ RadSafe ] Beta emitters and external risks

[John Jacobus]

Mike,
Thanks.  Yes, we do use Y-90 and I-131.  

Actually, you comments lead me to The "Radionuclide
and Radiation Protection Handbook 2002."
http://rpd.oxfordjournals.org/cgi/reprint/98/1/1

The external exposure from an infinte plane source of
I-131 betas at 10 cm is 0.074 mSv/hr/MBq/cm^2, which
is about 16 times the gamma dose.  From P-32, the dose
rate at 10 cm is 0.14 mSv/hr/MBq/cm^2.  For F-18, that
that is 0.094 mSv/hr/MBq/cm^2.  

I don't want to cut the discussion short, so does
anyone else have any criteria they use, or thoughts on
this?

--- "Stabin, Michael"
<michael.g.stabin at Vanderbilt.Edu> wrote:

> 
> I would certainly worry about Y-90, if your
> institution handles this.
> I-131 betas are an external hazard, though we
> usually worry more about
> the gammas and about intakes of the radioiodine. 
> 
> 
> Mike
> 
> Michael G. Stabin, PhD, CHP
> Assistant Professor of Radiology and Radiological
> Sciences 
> Department of Radiology and Radiological Sciences 
> Vanderbilt University 
> 1161 21st Avenue South
> Nashville, TN 37232-2675 
> Phone (615) 343-0068
> Fax   (615) 322-3764
> Pager (615) 835-5153
> e-mail     michael.g.stabin at vanderbilt.edu 
> internet   www.doseinfo-radar.com
> 
>  
> -----Original Message-----
> From: radsafe-bounces at radlab.nl
> [mailto:radsafe-bounces at radlab.nl] On
> Behalf Of John Jacobus
> Sent: Saturday, October 15, 2005 7:59 PM
> To: daleboyce at charter.net; radsafe at radlab.nl
> 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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> 


+++++++++++++++++++
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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