Radiological assessment of natural radionuclide in Kwakwachi irrigation water canal in Kano State Nigeria

Abstract

This study examines the levels of natural radionuclides in soil samples from the Kwakwachi irrigation canal, assessing potential radiological risks to the local population. Using gamma spectrometry at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria, we analyzed randomly collected soil samples for radionuclide content. Results showed that potassium-40 activity ranged from 28.43 to 85.01 Bq/kg, radium-226 from 12.70 to 31.12 Bq/kg, and thorium-232 from 21.78 to 45.22 Bq/kg. The mean concentrations for these radionuclides were all below their respective global averages (400 Bq/kg for 40K, 35 Bq/kg for 226Ra, and 30 Bq/kg for 232Th). Calculated indices—including radium equivalent, external and internal hazard indices, and gamma index—were also within internationally recommended safety limits. The average absorbed gamma dose rate was 55.20 nGy/h, below the global mean of 60 nGy/h. However, the annual effective dose for soil samples slightly exceeded the worldwide average of 0.07 mSv/y.