Comparative assessment of doses and health risks for students (pupils) and employees of several educational institutions in the Leningrad region, depending on methods and approaches to measuring indoor radon concentration
Authors: Vasilyev A. S. , Romanovich I. K. , Kormanovskaya T. A. , Kononenko D. V. , Istorik O. A. , Eremina L. A. 
Published: June 2022

According to the annual information packet “Radiation exposure doses to the population of the Russian Federation”, internal exposure to radon has been the main contributor to the annual dose for the population for many years. The paper presents results of a comparative assessment of doses and health risks for students (pupils) and employees of four educational institutions in the Kingiseppsky district of the Leningrad region due to exposure to radon and its progeny. Evaluation of the doses and risks was based on results of instant and long-term measurements of indoor radon concentrations published earlier. Individual annual effective doses to students (pupils) and employees due to exposure to radon while in the building of an educational institution, calculated on the basis of the results of instant measurements of radon EEC, ranged from 0.34 to 4.87 mSv/year for different institutions. However, calculation on the basis of the results of long-term measurements of radon concentration resulted in the dose values 2-4 times higher (from 1.40 to 14.79 mSv/year). These results do not reflect the real exposure scenario, since solid-state nuclear track detectors were exposed continuously, including nights, weekends and holidays (i.e. periods of actual absence of people in the buildings of the educational institutions). Based on the results of instant measurements of radon EEC, the contribution of radon and its progeny to the individual annual effective dose due to all natural sources of ionizing radiation to students (pupils) and employees was 59% (2.21 mSv/year) in the kindergarten of Opol’e, 61% (2.41 mSv/year) in the kindergarten of Falileevo, 82% (6.81 mSv/year) in the school of Falileevo, and 82% (7.11 mSv/year) in the school of Bol’shaya Pustomerzha. According to the classification established in sanitary rules and norms OSPORB 99/2010, the exposure of students and employees of the surveyed schools is classified as “increased” (from 5 to 10 mSv/year) when using the results of instant measurements of radon EEC, and is classified as “high” when using the results of long-term measurements of radon concentration (more than 10 mSv/year). The average individual lifetime risk of radon-induced lung cancer death (based on the results of instant measurements of radon EEC) for students (pupils) and employees was 3.8∙10–4 in the kindergarten of Opol’e, 4.1∙10–4 in the kindergarten of Falileevo, 1.2∙10–3 in the school of Falileevo, and 1.2∙10–3 in the school of Bol’shaya Pustomerzha. However, calculation on the basis of the results of long-term measurements of radon concentration resulted in the risk values from 1.5 to 2.4 times higher. The results obtained can be used to improve the method of monitoring of indoor radon concentration in existing operated public buildings in the Russian Federation, which in turn will make it possible to obtain correct values of doses and health risks.