RADIOLOGICAL SAFETY ASSESSMENT OF SOIL SAMPLES FROM SOME WASTE DUMPSITES IN KANO METROPOLIS
Investigations were carried out to determine the presence of natural radionuclides in some selected dumpsites and evaluate the hazards these may have on the people living around the locations in Kano metropolis, Nigeria. Gamma-ray spectrometry with [NaI(Tl)] detector (Canberra, model 727) at the Centre for Energy Research and Training, Ahmadu Bello University Zaria, Nigeria, was used to determine the concentrations of radionuclides in the soil samples randomly collected from study area. The results show that activities of 40K ranges from 242.15 to 697.51 Bq/kg, 226Ra ranges from 12.75 to 57.24 Bq/kg and that of 232Th ranges from 20.57 to 128.51 Bq/kg in all the analyzed samples. However, the results show that, the average value of 453.19Bq/kg of the activity concentration of 40K found in this study has exceeded the world average value of 400Bq/kg, and there was a higher activity concentration of232Th at all the dumpsites. The average values for radium equivalent, external index, internal index and gamma level index were 148.4Bq/kg, 0.401, 0.460 and 0.544 respectively in all the samples are lower than the suggested maximal admissible value of 370Bq/kg, 1,1 and 1 respectively. The average value of the absorbed gamma dose rates to gamma radiations is 67.84(nGy/h) for the samples, which was higher than the recommended world average value of 60 (nGy/h). However, the average annual effective dose was 0.028 (mSv/y) in the samples, and were lower than the world average 0.07 (mSv/y).