Variation of Radon Gas Emanation with Altitude in Some Parts of Greater Accra

Abstract

The study to ascertain the correlation between the concentration of radon gas (²²²Rn) at a relatively higher altitude and that of the concentration at a lower altitude with seismic activity and geological formation was carried out at McCarthy Hill and GAEC using LR-115 solid state nuclear track detectors. A total of 180 track detectors were buried in a grid form at a depth of 75 cm covering an area of 576 sq. meters with intervals of 12 meters between the holes. The radon concentrations varied from 0.27 ± 0.04 kBq m^?3 to 86.30 ± 2.94 kBq m^?3 for Site A and 0.72 ± 0.04 kBq m^?3 to 51.98 ± 1.75 kBq m^?3 for Site B, whiles a variation from 1.22 ± 0.102 kBq m^?3 to 123.23 ± 0.072 kBq m^?3 was determined for Site C. Even though, all the three sites are located along the Akwapim fault zone, an anomaly of more than 5? was observed at GAEC  with a mean concentration of 37.39 ± 0.350 kBqm^-3 whiles  mean concentrations of 10.00 ± 0.126 kBqm^-3 and 8.07 ± 0.069 kBqm^-3 were obtained for sites A and B respectively at McCarthy Hill. The anomaly observed at G.A.E.C could be attributed to the geological setting of the landscape with respect to the altitude of the study area and its closeness to the Eastern Boundary fault compared to the study area at McCarthy Hill.

Keywords: radon concentration, altitude, correlation, LR-115, anomaly, Eastern Boundary fault.