Individual biological dosimetry covering chromosomal analysis and elec
tronic paramagnetic resonance spectrometry has been performed in 1300
subjects exposed to ionizing radiation after the Chernobyl accident. C
umulative radiation doses above 40 ImC were registered in 5 %, about 1
00 ImC in 1 % of the examinees. In 1 % of cytogenetic investigations t
here appeared multiaberrant cells indicative of hot particle incorpora
tion. Regional epidemiologists do not record changes in the incidence
of hematological diseases. This may be explained by a small percent of
the dose carriers, rare occurrence of hematological disorders and the
time of radiation-induced oncogenic effects. The above representative
group exposed to definite radiation doses may serve the subject of ep
idemiological surveys on the role of low-dose and low-rate radiation i
n pathogenesis of human diseases.