Re: occupational doses and restricted areas

[mikeg@SLAC.Stanford.EDU (Michael P. Grissom)]

1.  My interpretation of the situations identified would be as 
follows:

>1) A radiologist was telling nurses that if they held patients
>during xrays, they were subject to the dose limits for general
>public since they are not "radiation workers". I reread the state
>regs and concluded that this is clearly an "occupational exposure".
>Do you agree?

The nurse is receiving dose due to a work assignment.  Hence, it IS
an occupational dose.  Question, is the nurse regularly assigned to the
Radiology department and does he/she receive training in radiation 
generated by machine issues (analogous to 10CFR19 training, i.e., 
commensurate with the radiological health issues)?  If it is a nurse 
not trained and monitored routinely, such as a ward person not routinely 
badged, then you're headed into a collision with the radiologist (and
maybe should be anyway)!  Mainly, WHY does any patient need to be held? 
Restraints have a purpose.  This same argument has been used as 
justification for using the patient's family members (presumably not 
occupational workers!) to hold them--usually seen with pediatric cases.
I know exceptions doubtless exist, but I would never encourage this
practice in a modern radiology clinic.

>2) A more serious question has to do with the stress lab in Cardiology
>where injections of Tc-99m Cardiolite are performed. Should observers
>be allowed in hte room and should they be badged or 'trained' in
>some  way? What dose limits apply?

My approach would be to provide 10CFR19 training to the Cardiology staff.
Between high activity Tc-99m studies (not just Cardiolite) and Tl-201
studies, among others, as well as radiographic procedures and the inter-
catheterization labs, the Cardiology folks often are occupational workers
(and receive some of the highest doses seen in the hospital)!  They may 
not all require monitoring, but they all should get the training
if they have access to the tread mills (occasional decontamination
sites) and other stress inducers seen in those clinics.  As for the
issue of observers, one approach could be to provide an indication of
unrestricted vice restricted area (the old 2 mR/h line).  This can be 
very tricky in the confined spaces many clinics are located in.  
Physicians are not prone to take restrictions lightly!

Again, these are mere opinions and not any organization's official
position.
-----------------
Michael P. Grissom
mikeg@slac.stanford.edu
Phone:  (415) 926-2346
Fax:    (415) 926-3030