Characteristics of the Cohort of Personnel of the Sublimate Production of the Siberian Chemical Plant Involved in Working with Plutonium-239

239Pu has the property of initiating radiogenic diseases in workers who come into contact with it during their occupational activities. To study adverse medical and biological effects and to study in detail the potential consequences of plutonium exposure on the body of personnel at nuclear energy facilities, it is necessary to form a cohort of persons involved in working with this isotope. The purpose of the study is to form and characterize a cohort of Siberian Chemical Plant sublimate production employees involved in working with 239Pu in the period 1953–2000. The source of information for forming the cohort was the database of the regional medical and dosimetric register of the population of closed administrative-territorial formation Seversk and the personnel of the Siberian Chemical Plant, containing personal, dosimetric, medical, and biological information regarding all current and former employees of the Siberian Chemical Plant (about 65 000 persons) since the founding of the enterprise until now. As part of this work, a cohort of sublimate production employees involved in work with 239Pu in 1953–2000 was formed (1052 persons, 577 men and 475 women). The dosimetric, medical, and biological characteristics of workers included in the sublimate production cohort are given. The created sublimate production cohort will make it possible to conduct comprehensive retrospective and prospective epidemiological studies to assess the morbidity and mortality of nuclear energy facilities employees, as well as to draw scientifically based conclusions regarding the role of 239Pu in the initiation of the most important socially significant non-infectious diseases (for example, malignant neoplasms, diseases of the circulatory system etc.) and mortality from these diseases. The scientific data obtained as a result of this study will make it possible to determine the main directions for organizing a system for assessing risks to the health of personnel at sites for the decommissioning of nuclear facilities and the formation of a set of measures aimed at improving the health-saving system of nuclear facilities employees and extending their working longevity.