Correlation Between Soil-gas Radon and Soil-surface Radon Concentration and Estimation of Annual Effective Dose From Outdoor Concentration in Abeokuta, Southwestern Nigeria

Abstract

Abstract In the U series, Rn − 222 (T1/2 = 3.82 days) builds up more quickly in homes. Although it originates from rocks and dirt, it dissolves in water. A RAD7 solid state detector was used to test the outdoor and soil gas in-situ radon-222 activity at 26 locations in Abeokuta, Nigeria. The six geological formations that were picked for a cell and spaced at least 3 km apart served as the basis for choosing the measuring site. The Global Positioning System compass was used to determine the locations of the measurement sites. Outdoor radon levels ranged from (0.001 to 4530) Bqm− 3 while soil gas levels ranged from (52.5 to 19250) Bqm− 3. In comparison to the reference level for outdoor radon recommended by the International Commission on Radiological Protection (ICRP), which ranges from (100 to 300) Bqm− 3, the average outdoor radon concentration value measured was 463.52 Bqm− 3. The exhalation rate ranged from (0.000108 to 0.0395) Bqm− 2s, and the rate of production of soil gas activity ranged from (0.00011 to 0.0404) Bqm− 3s. The mean annual effective dose from outdoor radon activity was determined to be 4.242 mSv/year, which is greater than the ICRP-recommended limit of 1 mSv/year for dosage from public exposure. The annual effective doses ranged from 0 to 16.57 mSv/year. The measured values did not correlate, which may be partially explained by the characteristics of the soil and by meteorological conditions.