Assessment of Indoor and Soil-Gas Radon Concentration of a Quarry Site in Eiyekorin, Kwara State

Abstract

The toxic health effect of human exposure to radon gas which is radioactive in nature has attracted extensive research attention worldwide. Since direct experiments on the effect of earthquakes on radon release are difficult to conduct, a possible alternative is to use man-made explosions as an earthquake surrogate and investigate the corresponding effect on radon concentration. This study aims at investigating the soil-gas radon concentration in an active quarry site and areas outside the quarry, and the infiltration of the gas into the indoor environment was measured in order to access the occupational exposure risk. Soil gas radon concentration was taken at 30 random locations within the quarry and areas outside the quarry using RAD7, likewise 10 indoor radon gas in offices and homes were measured using an active radon detector manufactured by Durridge Incorporation in USA and comparative analysis of the difference between the two locations were done. The mean of the soil-gas radon concentration in the quarry site is 24968.84 ± 6913.204Bq/m3 while that of outside the quarry is 9664.67 ± 4992.86 Bq/m3. The result shows higher values of radon-gas concentration in the quarry site compared with area outside the quarry and when compared to the International Commission on Radiation Protection (ICRP) suggested value of radon concentration in soil and sediment, which is in the range of 0.4 to 40 KBqm-3, result shows that most location within the study area are higher than these limits. Also, the radon in air indoor and outdoor was taken at the offices located within the quarry and occupational exposure risk was carried out. The average of radon in air indoor and outdoor was found to be 31.12 Bqm–3 and 10.12 Bqm–3 respectively with higher values found indoor. However, the values are found to be below the recommended value of 300 Bq/m3 by ICRP publication for homes and workplaces.