ASSESSMENT OF RADIOACTIVITY CONCENTRATION IN SOIL OF SOME MINING AREAS IN CENTRAL NASARAWA STATE, NIGERIA

U. Ibrahim, T.C. Akpa, I.H. Daniel

Abstract


A study was conducted to determine 226Ra, 232Th, and 40K
natural  activity  concentrations  in  surface  soils/sediments  of
some  mining  areas  in  Central  Nasarawa  State  Nigeria,  using
Sodium  Iodide-Thallium  Gamma  Spectroscopy.  Seven  major
sites were  identified  from the highly mining areas  of the zone
and a total of twenty  (21) samples were collected throughout
the whole accessible areas. From the analyzed samples, mean
natural activity concentrations were determined and the results
show 403.963±7.29 Bq/kg, 32.52±4.65 Bq/kg and 56.23±2.30
Bq/kg  for  40K,  226Ra  and  232Th  respectively.  The  results
obtained were a bit lower compare to the World average value,
except for 232Th which is higher than the World average value
with a difference of 20.23  Bq/kg.  The evaluated annual mean
effective  dose  is  0.04±2.7  mSv/yr.  This  is  far  less  than  the
annual dose limit for members of the public. The mean Radium
equivalent  activity  is  141.56±7.2Bqkg- 1.  The  average
background radiation absorbed doses at the two spots are 5.81
±0.08 mSv/y and 8.45±0.56 mSv/y. This is higher compare to
worldwide  average  of  1mSvy-1  given  by  IAEA  (1996)  and
UNSCEAR (2000). This implies that the people near the mining
sites are likely to receive little or no  radiation  dose when  the
stay outside or inside their houses.

Full Text:

PDF


Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 Unported License