Improvement of accuracy of chromosome aberration analysis for biological radiation dosimetry

The frequency of chromosome aberrations in circulating lymphocytes is accep ted as being the most reliable indicator of the absorbed dose of radiation. Researches done to improve the accuracy of cytogenetic analysis are descri bed in this review. These include investigations of in vitro factors that a ffect the yield of radiation-induced aberrations and of in vivo factors tha t affect the chromosomal radiosensitivity of individuals. Improved chromoso me-painting methods for accurate judgment of dicentrics and translocations are introduced. The practicality of these advanced cytogenetic techniques i s shown by examinations of individuals exposed in the radiation accident at Tokaimura in 1999.