Monitoring of annual effective dose (AED) in surface soils of Ahero rice fields, Kenya

The  annual  effective  doses  (AED)  both  AED  (in)  and  AED  (out)  in  the  surface  soils  of  Ahero rice fields, Kenya were investigated. The associated health risk of the soils from the four  fields  Field  1,  Field  2,  Field  3  and  Field  4  was  measured  using  gamma  ray spectrometric  technique  employing  Sodium Iodide  Thallium  doped  detector.  Five  surface soil samples were collected at a depth of 15 –20 cm from the Field 1, Field 2, Field 3 and two  samples  from  Field  4.  The  average  AED  (in)  of  0.30 ± 0 . 01 mSv/y  and  an  average AED (out) of 0.20± 0.01 mSv/y for field 1, an average AED (in) of 0.19 ± 0 .01 mSv/y, an  average AED  (out)  of 0.20 ± 0 .01 mSv/y  for  field  2,  an  average  AED  (in)  of 0.28 ± 0.01 mSv/y and  an  average  AED  (out)  of 0.18 ± 0 .01mSv/y  for  field  3  and  an average AED (in) of 0.34 ± 0 .01mSv/y and an average AED (out) of  0.23 ± 0 .01 mSv/y for  field  4.  All  the  AED  values  both  in  and  out  from  the  four  fields  were  below  the recommended  level  of  1mSv/y.  The  values  indicate  that  there  is  no  health  hazard associated  with  the  surface  soils  of  the  study  area  to  the  farmers  and  the  general population