Biological indicators for radiation damage.

Methods for estimating radiation dose using biological indicators have made rapid progress during recent years. Chromosome analysis in lymphocytes still plays a central role, but it is no longer the only quantitative system in biological dosimetry. The best approach seems to be to combine several of the assays exploiting their specific advantages: the high sensitivity in the case of dicentrics in lymphocytes (starting at about 0.05 Gy low-LET radiation), the broad dose range covered by the electron spin resonance technique (0.5-100 Gy), the possibility of identifying the localization of partial-body exposure when determining hair diameter, and the individual prognostic information obtained from changes in the frequency of blood cells after exposures exceeding about 1 Gy. In specific situations other methods may replace or supplement these indicators for radiation damage.