Re: Dose estimates when dosimetry is lost/damaged

[Bob Flood <bflood@SLAC.Stanford.EDU>]

A dosimetry processor provides a measurement service; additionally, the
service may also provide dose tracking and reporting to its customers. What
Sandy Perle is saying is that the processor should be reporting
measurements (and only measurements) to its customers, and identifying
those measurements with potential or actual problems. If dose tracking
services are supplied, the service only tracks the doses. The service has
no way to know if any dose measurement is appropriate, and thus can only
make assumptions (and we all know that all assumptions are wrong). The
reality is that a processing lab can determine the dose to the dosimeter
very well; whether the dose to the person assigned that dosimeter is at all
close to the dosimeter measurement is another question altogether.

The accuracy of the measurements is the processor's responsibility. The
accuracy of the doses in the dose tracking system are the responsibility of
the licensee/operator, i.e., the people responsible for controlling the
radiation exposure. It is up to the licensee to determine whether a
measurement should not be used and to determine doses in the absence of a
usable measurement. If the service includes dose tracking, then the
licensee must (naturally) provide revised doses to the service. AND the
service should always keep the original measurment data, in addition to the
revised doses.

I heartily agree that a service should not be generating dose estimates
without customer input. One technique for estimating doses is to look at a
person's dose history and evaluate whether the exposure for the period in
question was different from the person's previous experience. It is a
common case for a person to have zero dose for years and provide a
statement that he/she didn't do anything different this time - this is a
reasonable basis for assigning an estimate of zero as the dose of record.
The service can provide the dose history info, but not the rest of the
investigation process.


Bob Flood
Stanford Linear Accelerator Center
(415) 926-3793     bflood@slac.stanford.edu
Unless otherwise noted, all opinions are mine alone.