Radiological Risks from Natural Radionuclides in Surface Soil of Agbara Industrial Area, Ogun State, Nigeria

Abstract

Measurement of natural radioactivity in soil samples from the Agbara Industrial area, Nigeria, was measured using gamma-ray spectrometry with NaI (Tl) detector. The concentration of 238U ranged from 10.21±3.50 to 67.41±18.2 Bqkg^-1 , from 26.43±10.8 to 96.24±18.81 for 232Th and from 298.65±60.70 to 840.52±150.25 Bqkg^-1 for 40K. Their means were, respectively, 28.69±11.00, 45.86±10.25, and 481.22±106.17 Bqkg^-1 . Annual effective varies from 0.08 to 0.16 mSv y^-1 with a mean of 0.11 mSv y^-1 . The mean contamination factor was 0.87 for 228Ra, 1.02 for 232Th and, 1.15 for 40K.The soil is moderately polluted with 232Th and 40K. The Pollution Level Index indicates a drop in soil quality in  about 50% of the areas covered. The mean cancer risk (0.4 x 10^-3 ) obtained in this study is above the World Health  Organization limit, indicating a high probability for inhabitants to develop lung cancer in the long term when a lifetime is  spent in this area under study.