[en] It has been found that the personnel of the 'Ukrytie' depending on complex and configuration of work harmfulness (including level of accumulated dose of general exposure) has specific picture of peripheral blood that accounts for presence of adaptive reactions of increased and steady activation type. Taking into consideration that the latter easily transforms into stress one it is necessary to develop undertakings to prevent occurrences and progress of acute and chronic stress reactions in the personnel, especially when at the Object. It has been shown that certain part of the staff is infected with hepatitis C. There are strong grounds to believe that this factor is essentially higher as compared to those infected at the Kiev blood transfusion station