MEASUREMENT OF ACTIVITY CONCENTRATIONS OF NATURAL RADIONUCLIDES IN THE TOP SOIL OF UNIVERSITY OF AGRICULTURE, ABEOKUTA, (UNAAB) FARMS

Abstract

The natural radioactivity levels in the soils of University of Agriculture Abeokuta farms were measured.        20 soil samples were collected to a depth of about 10cm in twelve different farmlands within UNAAB        community.    The   average  activity  concentrations  obtained  for  the  three  radionuclides  were        520.13±32.06 Bq/kg for 40K, 33.66±23.27 Bq/kg for238U and 49.83±15.61 Bq/kg for232Th, respectively.        The distributions of these radionuclides were found to be uneven. The value of Uranium-238 was the        same at locations 4 and 16 but not detectable at locations 9 and 11, respectively. The average values        of the absorbed dose rates in air of each radionuclides were found to be 21.84 nGy/hr for 40K, 14.99        nGy/hr   for  238U   and   33.19   nGy/hr   for  232Th.   The   baseline   average   outdoor   annual   effective   dose        equivalent in UNAAB farms due to the radioactivity concentrations was found to be 86.92±28.37mSv/        yr. This value can be taken as representing the baseline values of natural radioactivity as no artificial        radionuclide was detected at any of the locations visited.