Uncertainty in assessment of radiation doses to Russian clean-up workers residing in territories contaminated with radionuclides

Results of estimating effective radiation doses received by 5079 Chernobyl clean-up workers during their permanent living in territories of Bryansk, Kaluga, Tula and Orel oblasts contaminated with radionuclides are presented in the article. External radiation doses received by clean-up workers during their activities towards mitigating consequences of the Chernobyl accident were higher, on average, than effective doses of chronic exposure to radiation they received over the period of permanent living in radioactively contaminated territories. Geometric standard deviation of individual doses of internal radiation to thyroid and whole body was 3, and standard geometric deviation of individual doses of external radiation was 1.5. Values of individual effective doses including uncertainty accumulated to 2015 in different residential communities were equal to geometric average doses and average effective doses, at the same time mathematical expectations of individual doses and average effective doses in the communities differed significantly. If uncertainty in radiation doses received by clean-up workers residing in contaminated areas is taken into account, radiation risk values can be biased.