ABSTRACT
Objective To use three different methods in attempt to estimate the biological dose of the patient partially exposed to 192Ir source at5.7 accident in Nanjing,so as to provide dosimetric information for clinical remedy of exposed patients in the emergency of a nuclear accident.Methods Peripheral blood samples were collected on days 5 after exposure.The biological dose was estimated by the yields of dicentrics plus rings ( dic + r),cytokinesis-block micronuclei (CBMN) assay and nucleoplasmic bridge plus FHC (NPB + FHC).The homogeneity of radiation exposure was examined by Poisson distribution of dicentrics.Results By using three different methods,the whole body equivalent dose was dic + r estimated to be 1.51 Gy (95％ CI 1.40-1.61),1.47 Gy (95％ CI 1.36-1.60) by CBMN and 1.30 Gy (95％ CI 1.00-1.60) by NPB + FHC,respectively.A non-poisson distribution was also detected,suggesting partial body radiation exposure.Conclusions The estimated whole body equivalent dose ot a non-uniform radiation exposure was consistent with clinical diagnosis,suggesting that the yields ofdic + r,CBMN,as well as NPB + FHC,are efficient approaches to the estimation of biological doses.