QUANTIFICATION OF LOW-LEVEL RADIATION EXPOSURE BY CONVENTIONAL CHROMOSOME ABERRATION ANALYSIS

Chromosome dosimetry, in its conventional form largely based on scorin g of dicentrics and ring chromosomes in human blood lymphocytes, is th e most widely distributed and reliable biological technique in radiolo gical protection to estimate individual whole-body doses of about 100 mGy of low-LET radiation. Attempts to detect and quantify effects even of lower acute doses or protracted and chronic exposures have been re peatedly performed and the results revealed inherent limitations of th is approach. Most relevant items, such as extrapolating from high-dose to low-dose effects, the influence of background frequency of dicentr ics on the dose estimates, dose accumulation and concomitant temporal decline of the yields of unstable dicentrics or the statistical analys es of the data and their implications for quantifying low-level radiat ion exposure will be discussed in this report.