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

Abstract

Assessment of radioactivity concentrations of 40K, 238U and 232Th in
surface soil samples of major markets at Sagamu, Ogun State in Nigeria
had been determined by gamma spectrometry using Sodium Iodide
Thallium doped NaI (TI) detector coupled with a pre-amplifier base to a
multiple channel analyzer (MCA). 10 samples each were collected from
three major markets: Falawo, Awolowo and Sabo. Highest radioactivity
concentrations of 40K, and 238U were obtained from Falawo market soil
samples with values 1274.26 ± 4.26 Bq/kg and 40.72 ± 3.12 Bq/kg
respectively while that of 232Th was obtained from Sabo soil sample with
value 115.62 ± 16.39 Bq/kg. The mean external hazard index (Hex) and
mean internal hazard index (Hin) for all the soil samples from Falawo
market 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 be
0.594 Bq/kg and 0.658 Bq/kg respectively. All the values obtained were
less than 1.0 Bq/kg as recommended for safety and therefore have no
negative radiological health implication to the people within the markets
and their environs.

Keywords: Radioactivity concentration, radionuclide, hazard index,
surface soil.