Assessments of natural radioactivity and determination of heavy metals in soil around industrial dumpsites in Sango-Ota, Ogun State, Nigeria

The activity concentration of natural radionuclides in soil samples from industrial dumpsites in Sango-Ota were determined using gamma-ray spectrometry with NaI(Tl) detector. The mean activity concentration of 226Ra, 232Th and 40K was 3.0 ± 1.2, 33.3 ± 9.8 and 122.1 ± 20.6 Bqkg-1, respectively. Radium equivalent activities were calculated to assess the hazards arising from the use of the soil sample in agriculture. All the calculated values were lower than the world average. The mean concentration of heavy metals in the soil samples were 33.6, 2.9, 3.8, 2.7, 48.9, 1,5, 34.5 and 0.8 mg l-1 for Cu, Mg, Ca, P, Fe, Pb, Zn and Cd, respectively. The concentrations of Cd, Cu and Pb were higher than the natural permissible range in soil. Therefore, the government should discourage the use of the soil around dumpsites for planting because of the presence of heavy metals in the sites. (author)