Assessment of radionuclides content of dumpsites within Kaduna Metropolis

Abstract

This study assessed the concentration of radionuclides (Ra-266, Th-232, U-238, and K-40) in selected dumpsites within some Local Government Areas of Kaduna State. Radiological analysis was carried out using a gamma spectrometer (HPGE) located at the Energy Research Center, University of Ibadan, Nigeria. The results of the concentration of Ra-266, Th-232, U-238 and K-40 in the study area were as follows: 196.12 – 239.14 Bq/kg, 126.79 – 171.32 Bq/kg, 84.96 – 115.96 Bq/kg, and 317.11 – 521.77 Bq/kg respectively for Chikun LGA; 213.84 – 268.98 Bq/kg, 102.17 – 122.90 Bq/kg, 110.89 – 137.80 Bq/kg, 407.64 – 486.38 Bq/kg respectively for Igabi LGA; 187.15 – 364.50 Bq/kg, 166.04 – 387.00 Bq/kg, 97.35 – 180.57 Bq/kg, and 541.72 – 801.08 Bq/kg respectively for Kaduna North LGA; and 128.98 – 293.45 Bq/kg, 139.43 – 182.96 Bq/kg, 70.57 – 132.02 Bq/kg and 526.19 – 707.42 Bq/kg respectively for dumpsites in Kaduna South. The results revealed that K-40 had the highest concentration in all the study areas and was found to be above the UNSCEAR (2000) recommended limit of 300 bq/kg. Ra-266, Th-232, and U-238 were found to be 37, 31, and 51 Bq/kg above the UNSCEAR (2000) recommended limits of 35, 30, and 50 Bq/kg, respectively. The annual effective dose was in the range of 1.23–2.30 mSvy^(-1) above the UNSCEAR (2000) recommended safety limit. The radioactivity level in the study areas was high; therefore, continuous exposure to these radionuclides and their progenies may pose a severe risk to public health. All the sampled radionuclides were found to be within the recommended standard of ≤1.0 WHO reference values.