Major life expectancy risks in the military liquidators of the Chernobyl disaster in 1986

Relevance. The current realities (including the special military operation in Ukraine) are impregnated with a sharp increase in nuclear terrorism threats. In this regard, elimination of medical consequences of the 1986 Chernobyl nuclear power plant (Chernobyl NPP) disaster – the largest man-made radiation disaster in human history – is valuable experience that merits thorough analysis.The objective is to analyze risk factor impact on the life expectancy of liquidators engaged in eliminating the Chernobyl disaster consequences.Methods. The study analyzed initial accounts and reports of the Army Medical Register of the Ministry of Defense of the Russian Federation, containing information on 158 liquidators of the Chernobyl NPP disaster in 1986. The study focused on liquidator life expectancy in correlation with the absorbed external γ and β radiation dose, age at disaster site deployment, length of stay, the phase of accident, and professional activity.Results and analysis. The liquidators did not show a robust correlation between the absorbed external γ and β radiation dose and life expectancy. The key factors affecting the life expectancy of Chernobyl disaster liquidators were age at the time of deployment (under 40 years), length of stay at the NPP (over 50 days), including during the acute phase, work involving high risks. The absorbed dose of external γ- and β- radiation did not contribute significantly to shorter life expectancy risks among Chernobyl liquidators.Conclusion. The study results allow to conclude that the length of stay in the hazardous radioactive zone and the age of liq uidators at the time of deployment are the likely high-risk factors, affecting life expectancy of Chernobyl liquidators. Meanwhile, none of the studied predictor factors showed any significant impact on the 25-year survival of Chernobyl liquidators.