Natural Radioactivity Concentrations and Dose Assessment in Shore Sediments along the Coast of Greater Accra, Ghana

Radioactivity concentration of Naturally Occurring Radioactive Materials (NORMs) in shore sediments (samples) collected along the coast of Accra were analyzed using a gamma spectrometry with a high purity germanium detector. The specific activity concentrations range from 8.60 Bqkg to 61.01 Bqkg with a mean of 29.78 Bqkg for K, 0.62 Bqkg to 148.80 Bqkg with a mean of 22.04 Bqkg for Ra and 0.17 Bqkg to 732.60 Bqkg with a mean of 108.60 Bqkg for Th. The K concentration compares well with the world average value while that for Ra and Th does not. The average absorbed dose rate was estimated to range from 0.75 nGyh to 509.38 nGyh with an average of 77.02 nGyh, while the average annual effective dose also ranged from 0.00 mSvy to 0.63 mSvy with an average of 0.09 mSvy was also estimated. The average radium equivalent activity and average external hazard index were also estimated to be 9.00 Bqkg and 0.48 respectively and they both compare well with internationally acceptable values.