Author(s):
1. Zdenka Stojanovska, Faculty of Medical Sciences, Goce Delčev University Stip, Macedonia
2. Jana Djounova, National Centre of Radiobiology and Radiation Protection, Bulgaria
3. Ilia Tasev, Ministry of Health, Sofia, Bulgaria, Bulgaria
4. Kremena Ivanova, National Centre of Radiobiology and Radiation Protection, Sofia, Bulgaria, Bulgaria

Abstract:
Radon is noble gas from the uranium-radium radioactive family, can leave its place of origin and enter the atmosphere. In the atmosphere, radon dynamic is affected by meteorological conditions. In order to study seasonal variations, a radon survey was conducted on 90 premises of buildings with public access (schools and kindergartens) in different regions of Bulgaria. For the purposes of the study, in each position two RADOSYS track detectors were exposed in two periods, the firs only in winter season and second for whole year. The annual radon concentration (CRn(y)) in 77 out of 90 premises is below 300 Bq/m3 (radon reference level in Bulgaria). While the seasonal values CRn(s) are lower than 300 Bq/m3 in 75 rooms. The average value of the seasonal variation coefficient CRn(y)/CRn(s) is 0.92. Seasonal radon concentrations were expected to be higher than annual, but this expectation was not confirmed for all sites, so the coefficients ranged from 0.36 to 2.19. Correlation between CRn(y) and CRn(s) was investigated, and it was significant at a 95% confidence level with probability p<0.0001 with the obtained coefficient of determination R2=83%. This indicates that using the liner model annual radon value could be determined due to seasonal measurements with 83% accuracy. The obtained results can optimize the protocols for carrying out the measurements in buildings with public access and will contribute to the more accurate assessment of children's exposure.

Key words:
radon,seasonal variation,track detectors,schools,kindergartens

Thematic field:
SYMPOSIUM A - Science of matter, condensed matter and physics of solid states

Date of abstract submission:
23.08.2023.

Conference:
Contemporary Materials 2023 - Savremeni materijali

Abstract