Application of cytokinesis-block micronucleus method in radiation accident in Xinzhou City of Shanxi Province

The authors report a radiation accident on November 19, 1992 in Xinzhou City of Shanxi Province, China. A woman patient, aged 24, with undetermined history of radiation exposure, was proved to have been exposed to high dose irradiation in the light of chromosome aberration in peripheral lymphocytes. The absorbed dose estimated based on the frequency of dicentrics plus rings was equivalent to 2.30 Gy of homogeneous whole body irradiation with the 95% confidence limit of 2.07-2.50 Gy. With this diagnosis, the following advice was offered: (1) immediate search for the radiation source with a view to eradicating as soon as possible the menace to the safety and health of local inhabitants; (2) medical surveillance of potentially irradiated people, estimation of exposure dose, and taking proper measures; and (3) appropriate treatment of the patient. After energetic effort, an abandoned sealed 60Co source was at last found. At the 38-70th days after the accident, the frequencies of chromosome aberrations and micronuclei were examined by cytokinesis-block micronucleus method for 34 individuals. Exposure doses were estimated by using the cytogenetic technique. The results of micronucleus and dicentric plus ring assays were similar, so that CB micronucleus method can be used for estimating exposure dose to individuals