Radioactivity concentrations and their radiological significance in sediments of the Tema Harbour (Greater Accra, Ghana)

Publication date: Available online 11 January 2017 Source:Journal of Radiation Research and Applied Sciences Author(s): Benjamin O. Botwe, Antonio Schirone, Ivana Delbono, Mattia Barsanti, Roberta Delfanti, Peter Kelderman, Elvis Nyarko, Piet N.L. Lens Studies on environmental radioactivity in tropical Africa are scarce. Therefore, a baseline study of natural (238U, 210Pb, 226Ra, 232Th, 228Ra, 228Th, 40K) and anthropogenic (137Cs) radionuclides was carried out on Tema Harbour (Greater Accra, Ghana) surface sediments and on their radiological significance. Grab surface sediment samples were collected from 21 stations within the Tema Harbour and their radioactivity concentrations measured by gamma spectrometry. The mean sediment radioactivity concentrations (Bq kg−1 dw) were 34 for 238U, 210 for 210Pb, 14 for 226Ra, 30 for 232Th, 29 for 228Ra, 31 for 228Th, 320 for 40K, and 1.5 for 137Cs. Large 238U/226Ra disequilibria were observed in the harbour sediments and a complex dynamics of several mixed sources of sediments within the Tema Harbour can be inferred from the spatial variations in the radioactivity concentrations. The estimated total absorbed dose rate in air (D), radium equivalent activity (Raeq), external hazard index (H ex ), annual gonadal dose equivalent (AGDE) and annual effective dose equivalent (AEDE) indicated no significant radiological risks from the sediment radioactivity concentrations. Application of the Environmental Risk from Ionising Contamin...
Source: Journal of Radiation Research and Applied Sciences - Category: Physics Source Type: research