Re: x-rays, IRB, etc.

["Chuck Pickering" <CPICKERING@engr-serv.usc.edu>]

Fellow Radsafers,

P.S. Rao was looking for risk language in informed consents.  At the 
University of Southern California, our Radiation Safety Committee has 
taken a strong stand that informed consents must provide numerical 
risk estimates.  Comparing the dose to some number of chest x-rays 
does not give the subject any information on risk.  What is the risk of 
a chest x-ray?

The standard language we use is something like:

"The total radiation exposure from this study is about 1/16 the yearly 
dose of background radiation received from the Sun and other natural 
sources.  The risk of cancer death from a dose of radiation this small 
is not known.  For comparison, the risk in persons exposed to more 
than 8,000 times this dose of radiation is about 8 deaths per 1,000 
persons, while the risk of cancer death due to all causes is 160 per 
1,000."

The doctors hate it, but our risk manager loves it.

Chuck Pickering
Radiation Safety Officer
USC Health Sciences Campus