Radiological impact assessment of natural radioactivity in soil and water in Cape Coast North, Central Region of Ghana

The objective of the study is to evaluate natural radioactivity and its radiological impact on the health of the populace within Cape Coast North. Soil and water samples were taken and analysed using a high purity germanium (HPGe) detector. Results for the average activity concentrations of 226Ra, 232Th, and 40K in soil samples range from 15.0 to 60.8 Bq/kg with a mean of 20.9 ± 7.2 Bq/kg, 16.3 to 97.2 Bq/kg with a mean of 43.8 ± 2.4 Bq/kg, and 4.7 to 411.4 Bq/kg with an average of 140.6 ± 4.2 Bq/kg, respectively. The absorbed dose rate in air and outdoor annual effective dose to the public were estimated to be 46.6 nGyh-1 and 0.1 mSv, respectively, which fell below the recommended average. The average activity concentrations of 226Ra, 232Th, and 40K in water samples were 1.4, 0.4, and 1.2 Bq/L, respectively. The annual effective dose is 0.4 mSv, which is greater than the WHO recommended level of 0.1 mSv/y.