Abstract

  Radon gas is one of the major terrestrial radiation sources that affect the general population. Its primary indoor sources are from the floor (especially if the floor is soil) and from building materials. It can be the source of alpha particles and gamma radiations, but the more dangerous one is the alpha particle because when inhaled, it is capable of harming the internal organs, especially the lungs. This study aimed to assess net radiation levels inside rural houses of Siltie, Wolayta and Sidama zones of Southern Ethiopia. The experiment was conducted in 12 village houses of the three locations and measurements of radon-222 (²²²Rn) concentrations were carried out both outside and indoor, using Alpha Guard, from December 2 - 13/2017. The houses differ in terms of ventilations and their floor covers. For each house, outdoor measurements were taken (to serve as background radiation) at three different locations, far from houses. The measurements were taken at four different heights (0, 0.5, 1.0 and 1.5 m) from the ground, always prior to indoor measurements. Indoor measurements were taken in four replications, at similar heights. Measurements were taken in morning hours starting from the time when the residents wake up and open their doors. The results obtained are summarized as follows. Both indoor and background radiations showed exponential decay of radon concentration with height. ANOVA tests among houses and among zones did not show significant differences both among houses and among zones. Ventilated houses showed lower mean values (reduction of 27.9%) and standard deviations of radon concentrations. Houses with covered floors also showed lower radon concentrations (reduction of 33.6%) compared to houses of uncovered floors. Based on IAEA limit, only one house from Wolayta zone exceeded the limit of 200 Bq/m³ based on indoor floor-level radon concentration values. None of the houses exceeded the limit at heights of 0.5 m or above. More study may be needed to assess radiation levels of the surrounding soils to know more about the differences among the zones.

Keywords: Alpha Guard; House Floor Cover; Indoor Radiation; Outdoor Radiation; Ventilated Houses

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Citation

Citation: Seifu Seta and Gelana Amente. “Assessment of Radon Concentrations Inside Houses of Siltie, Wolayta and Sidama Zones of Southern Ethiopia". Acta Scientific Microbiology 3.2 (2020): 82-95.

Copyright

Copyright: © 2020 Seifu Seta and Gelana Amente. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.