RADON AND THORON EXHALATION RATES FROM EARTHEN BUILDING MATERIALS USED IN HIGH BACKGROUND RADIATION AREAS OF HOMA AND RURI, KENYA. Issue 1 (28th October 2021)

• Record Type: Journal Article
• Authors: Odongo, Willis Otieno Gor; Chege, Margaret; Tokonami, Shinji; Hashim, Nadir; Kranrod, Chutima; Nyambura, Catherine
• Is Part Of: Radiation protection dosimetry. Volume 197:Issue 1(2021)
• Page Start: 12
• Page End: 18
• Publication Date: 2021-10-28
• Subjects: Radiation dosimetry -- Periodicals; Radiation -- Safety measures -- Periodicals; 363.1799
• DOI: 10.1093/rpd/ncab156
• Languages: English
• ISSNs: 0144-8420

Abstract

Abstract: 222 Rn and 220 Rn surface exhalation rates from earthen building materials used in high background radiation areas of Homa and Ruri, Kenya have been measured using an accumulation chamber coupled with RAD7 detector. Activity concentrations of 226 Ra and 232 Th in the building materials were determined by γ-ray spectroscopy. In Homa the average 222 Rn surface exhalation was 1 ± 0.1 mBqm −2 s −1, while that of 220 Rn was 18 ± 2 Bqm −2 s −1 ; in Ruri 222 Rn was 0.9 ± 0.1 mBqm −2 s −1 and 220 Rn was 25 ± 3 Bqm −2 s −1 . 222 Rn was 26 times lower than world average and 220 Rn was higher by a factor of 21. Average 232 Th in Ruri was 1094 ± 55 Bq/kg, three times that in Homa; 226 Ra was 129 ± 10 and 111 ± 6 Bq/kg in Homa and Ruri, respectively. There was a strong correlation between exhalation rate of 222 Rn and concentration of 226 Ra, as well as between 232 Th and 220 Rn. Thus, 220 Rn was the major contributor to the inhaled dose in earthen dwellings of the two regions.