Outcome measures in QECC

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  • resuspension factors,
  • intake per surface unit (surface contamination × surface area × time exposed ÷ respiratory protection factor),
  • intake per airborne unit (airborne contamination × time exposed ÷ respiratory protection factor),
  • intake per skin unit (skin contamination × area contaminated) and
  • other quantitative measures of the consequences of contamination.
QECC also includes quantitative results of historical accidents involving breached and unbreached sealed sources. This work (much of which was funded previously by the NRC) gives distributions of:
  • time-and-proximity factors, that is, the amount of time (hours) an individual would have had to spend at 1 meter from the unshielded source to receive the dose he or she actually received in the accident, and
  • fractions-taken-in, that is, the fraction of the activity in the source that became an intake,
from about 100 different accidents. These distributions showed little correlation between source activity and dose. The preliminary results from QECC data on contamination show similar trends. It is very likely that actual human experience with contamination will show that, on a dose or risk basis, current and proposed contamination standards are overly restrictive. We expect to confirm that intake is not generally associated with skin contamination alone.

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