Re: Personal Air Samplers

[StevenFrey@aol.com]

Mr. Monaghan -

Here are some things to consider in using PAS devices: 1) they require
active, conscious effort by the user to ensure they are in the right body
location, the right radioactive material area, and are not 'inadvertantly'
left behind in the changeout room, 2) their batteries require frequent
recharging and full discharge in order to prevent power-sapping 'memory'
failures from appearing, 3) their inherent low-airflow rates tend to
introduce greater error in the results compared to passive room air samplers
due to larger statistical counting flucuations around the smaller amounts of
activity collected, 4) they are a bulky nuisance to wear, 5) they do produce
some noise, 6) users can feel insulted by being told in effect that they
can't be counted upon to be smart enough to avoid airborne activity areas, 7)
they are expensive, and 8) maybe most importantly, they cannot by themselves
produce an accurate measurement of worker inhalation levels because they can
only sample the microenvironment immediately surrounding the sampler itself.

Instead, first try using a combination of other radiation safety measures:
advance assessment of the types, forms, and quantities of radioactivity
expected to be used, use of engineering controls such as ventilated hoods
and/or filtered ventilation systems to help keep airborne activity away from
workers, advance training of workers of  what to expect and how to minimize
intakes of radioactivity, employment of a sufficient number of
strategically-placed benchtop (i.e., passive) air samplers, frequent area
surveys for surface contamination, timely cleanup of any loose contamination
found, and bioassays as deemed appropriate from the results of the air
sampling and contamination surveys. Then and only then should PAS devices be
considered for use. And if used, they should be used only to corroborate
information gained from the above radiation safety measures, never as sources
of stand-alone information.

If the collective data shows no significant airborne activity levels or
intakes, you can reasonably conclude that your radiation safety program is
working, which is the main underlying goal.

Wishing you good fortune in your project, and hoping this PAS-sive pondering
helps.

Steve Frey, MS, CHP