  Using the first WBC unit installed in Fukushima Prefecture after the
accident, the radiocesium body burdens of 566 high-risk residents of Minamisoma
city were measured in July 2011 at the Minamisoma Municipal General Hospital.
The analysis of the data was challenging because this chair-type WBC unit did
not have sufficient shielding against background gamma rays, and methods had to
be developed to reliably compensate for the body-attenuated background
radiation. Fortunately, data for repeated tests of hospital staff members using
both the chair-type and well-shielded FASTSCAN WBC units, installed in
September 2011, were available, and could be used to check the validity of the
analysis. The CEDs of all subjects, estimated under the assumption of acute
inhalation in March 2011, were found to be less than 1 mSv.
