Assessment of radiological hazard indices from surface soil to individuals from major markets at Sagamu Ogun State, Nigeria

Assessment of radioactivity concentrations of 40K, 238U and 232Th insurface soil samples of major markets at Sagamu, Ogun State in Nigeriahad been determined by gamma spectrometry using Sodium IodideThallium doped NaI (TI) detector coupled with a pre-amplifier base to amultiple channel analyzer (MCA). 10 samples each were collected fromthree major markets: Falawo, Awolowo and Sabo. Highest radioactivityconcentrations of 40K, and 238U were obtained from Falawo market soilsamples with values 1274.26 ± 4.26 Bq/kg and 40.72 ± 3.12 Bq/kgrespectively while that of 232Th was obtained from Sabo soil sample withvalue 115.62 ± 16.39 Bq/kg. The mean external hazard index (Hex) andmean internal hazard index (Hin) for all the soil samples from Falawomarket were calculated to be 0.616 Bq/kg and 0.691Bq/kg respectively,and that of Awolowo market were 0.566 Bq/kg and 0.634 Bq/kg respectively. Also for Sabo market the mean values were calculated to be0.594 Bq/kg and 0.658 Bq/kg respectively. All the values obtained wereless than 1.0 Bq/kg as recommended for safety and therefore have nonegative radiological health implication to the people within the marketsand their environs.Keywords: Radioactivity concentration, radionuclide, hazard index,surface soil