Call for Volunteers to Participate in Thorium Study

["Carbaugh, Eugene H" <gene.carbaugh@pnl.gov>]

I've been asked to post the following message on RADSAFE by its author.
Interested parties should please respond directly to Tim Lynch by e-mail to
tim.lynch@pnl.gov.


Original Message-----

From:	Lynch, Timothy P 
Sent:	Friday, September 18, 1998 9:46 AM
To:	'radsafe@romulus.ehs.uiuc.edu'
Subject:	Call for Volunteers to Participate in Thorium Study

September 18, 1998

Researchers at Battelle's Northwest Division have developed an experimental
monitor to measure thoron (Radon-220) in exhaled breath as a tool to estimate
thorium activity in the body.  Thoron is the 6th radionuclide in the Th-232
decay series, which is a naturally occurring radionuclide used in government and
industry for a variety of purposes.   The purpose of this research study is to
compare results obtained from whole body counting measurements with results from
the experimental thoron-in-breath monitor to evaluate the accuracy of the thoron
breath monitor (TIBM) measurements for making estimates of the thorium activity
in the body.
 
To evaluate the accuracy of the thoron breath monitor, Battelle researchers are
interested in contacting individuals with known depositions of Th-232 that can
be measured using whole-body counting methods to solicit their participation in
this study.   Interested subjects will be briefed about the study and will sign
an informed consent form indicating their willingness to participate.  They will
be fitted with a facemask that covers the nose and mouth, but allows them to
breathe in air in a normal fashion.  Their exhaled breath will be collected in a
chamber connected to the facemask by a plastic tube.  The exhaled breath will be
collected for 20 minutes.  The thoron decay products are collected on a filter
and the filter is removed from the monitor and counted for at least 20  hours. 

The identity of the participants will be kept confidential and will be known
only to the researchers.  Only the results based on the measurement data will be
made available to the scientific community.  Individual cases will be coded with
an alphanumeric designation. (E.g. Case 98-I-01)  Upon request an individual can
receive a copy of their measurement results.   Preliminary estimates of the
thorium activity that could have been taken into the body should be available
within 1-2 weeks after the measurement.  However, information related to how and
when the intake or intakes occurred is needed to provide the best estimate of
the thorium intake.  If this type of information is not available the estimates
will be based on explicitly stated assumptions.  The current study is intended
to provide information about the accuracy of the results obtained with the TIBM
and consequently the accuracy of specific results may not be known until the
conclusion of the study.  Interpretation of the risk and possible health effects
is outside the scope of this project and individuals should discuss these
matters with qualified individuals knowledgeable about radiation protection. 

Arrangements can be made to bring the TIBM to a particular work site.  At
Department of Energy Sites the work will be coordinated with the Institutional
Review Board representatives.    However, measurements will also be made in
Richland, Washington where subjects may also receive a whole body count as part
of their participation in the study.  The length of the whole body count is 40
minutes.  Before the counts you will be asked to shower and change into a pair
of coveralls.  During the count you will need to lie on your back on the
counting platform and remain still.  

Persons interested in participating in the study should contact Tim Lynch in
Washington State at 509-376-6281 or via e-mail at tim.lynch@pnl.gov.  Please
pass this information on to anyone else that you feel may qualify for
participation in this study. 


Timothy P. Lynch	
Manager
Hanford In Vivo Counting Project
509-376-6281

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