1: Radiat Res. 2003 Aug;160(2):168-73.  

Retrospective dosimetry after criticality accidents using low-frequency EPR: a
study of whole human teeth irradiated in a mixed neutron and gamma-radiation
field.

Zdravkova M, Crokart N, Trompier F, Asselineau B, Gallez B, Gaillard-Lecanu E,
Debuyst R.

Laboratory of Biomedical Magnetic Resonance, Universite catholique de Louvain,
UCL, B-1200 Brussels, Belgium.

In the context of accidental or intentional radiation exposures (nuclear
terrorism), it is essential to separate rapidly those individuals with
substantial exposures from those with exposures that do not constitute an
immediate threat to health. Low-frequency electron paramagnetic resonance (EPR)
spectroscopy provides the potential advantage of making accurate and sensitive
measurements of absorbed radiation dose in teeth without removing the teeth from
the potential victims. Up to now, most studies focused on the dose-response
curves obtained for gamma radiation. In radiation accidents, however, the
contribution of neutrons to the total radiation dose should not be neglected. To
determine how neutrons contribute to the apparent dose estimated by EPR
dosimetry, extracted whole human teeth were irradiated at the SILENE reactor in
a mixed neutron and gamma-radiation field simulating criticality accidents. The
teeth were irradiated in free air as well as in a paraffin head phantom. Lead
screens were also used to eliminate to a large extent the contribution of the
gamma radiation to the dose received by the teeth. The EPR signals, obtained
with a low-frequency (1.2 GHz) spectrometer, were compared to dosimetry
measurements at the same location. The contribution of neutrons to the EPR
dosimetric signal was negligible in the range of 0 to 10 Gy and was rather small
(neutron/gamma-ray sensitivity in the range 0-0.2) at higher doses. This
indicates that the method essentially provides information on the dose received
from the gamma-ray component of the radiation.

Publication Types:
    Evaluation Studies
    Validation Studies

PMID: 12859227 [PubMed - indexed for MEDLINE]