Biological dose estimation by cytokinesis-block micronuclei assay for victims in Taiyuan radiation accident / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the value of cytokinesis-block micronuclei(CBMN)assay in estimation of the biological doses of the victims of radiation accident.Methods Samples of peripheral blood were collected from the 5 victims(Subjects 1-5)at 16 h after the radiation accident of Taiyuan,Shanxi Province.And the peripheral blood samples and bone marrow sample were collected from the victim No.1 at 23 and 24 h after the radiation.Eight days after the accident Subject 1 underwent allogeneic peripheral blood hematopoietic stem cell transplantation.At difierent time points in the period of 1 year after the accident.peripheral blood samples were collected from these 5 victims.CBMN assay was conducted on the peripheral blood lymphocytes on the samples,and the biological doses were estimated based on the micronuclei(MN)frequencies.The nuclear division index(NDI)obtained from in vitro irradiation experiment using high dose of 60Coγ-rays was used to estimate the exposed doses for Subject 1. Dynamic arialysis of the MN frequency for the 5 victims was performed in the period of 1 year after the accident.Results The MN frequency of Subject 1 surpassed the value corresponding to the upper limit of the MN dose.effective curve.The dose range estimated bv the combination of the CBMN and NDI (CBMN+NDl)assay was 10-20 Gy for Subject 1.The doses estimated by MN frequency for Subjects 2,3,4,and 5 were 3.6,2.9,2.3,and 2.9 Gy,respectively.The estimated doses were in accordance with those estimated by physicat method.chromosome aberration analysis.and clinical symptoms.Prominent decrease of the MN frequency was observed at 26 d after the accident(18 d after the transplantation)for Subject 1(u=3.295,P<0.05).Gradual decrease of MN frequency was observed after the accident for Subjects 2,3,4,and 5.The MN frequencies 1 month after the accident of Subjects 3,4,and 5 were all significantly lower than those 16 h later(u=6.874,4.526,and 7.811,P<0.05).Conclusions Quick and accurate.CBMN assay reinforces and verifies the result of chromosome aberration analysis.The new index CBMN+NDI assay is of reference valne for estimating higher dose of irradiation.