دراسة خلفية مظهر النشاط الاشعاعي في بعض الترب المستغلة وغير المستغلة

الملخص EN

The spatial distribution of the naturally occurring radionuclides 238U, 232Th and 40K activity concentration were characterized in (40) forty soil samples each from cultivated (fertilized) fields and virgin fields were randomly collected from agriculture research station site in Latifiyah area 35 km south Baghdad from the fertile soil depth of 0-30 cm.

As well as measuring the content of these radionuclides in common phosphate fertilizer used by workers at the station as one of the major shareholders in the outside terrestrial radiation.

Gamma ray spectrometry has been applied with using high purity germanium (HPGe) detector 40% efficiency associated with a multichannel analyzer (MCA) to measure radioactivity concentration and analysis of results using the Giene-2000 analytical program for the sample under study.

The mean radioactivity concentrations of 238U, 232Th and 40K were found to be 18.9±5.3, 9.78±3.2 and 439.3±33.5 Bqkg-1, respectively, in agricultural soils and 14.0±3.7, 7.5± 1.7 and 409.8±45.7 Bq kg-1, respectively, in vergin (not cultivated) soils.

It is clear that the use of phosphate fertilizers raises the radioactivity concentration in agricultural soil from its concentration in virgin (not cultivated) soil.

The mean value of radium equivalent activity (Raeq), orbed dose rates (DƔ), Inddor effective dose (Ein), outddor effective dose (Eout), gamma index〖(I〗_Ɣ), external hazard index (Hex)and internal hazard index (Hin) are 67.0 (Bq kg-1), 32.8 (nGyh-1), 0.161 (mSvy-1), 0.040 (mSvy-1), 0.484 (mSvy-1), 0.480 (mSvy-1) and 0.231 (mSvy-1), respectively, in agricultural soils and 56.2 (Bq kg-1), 27.9(nGyh-1), 0.137 (mSvy-1), 0.034 (mSvy-1), 0.416 (mSvy-1), 0.152 (mSvy-1) and 0.189 (mSvy-1), respectively, in virgin(not cultivated) soils.

The mean values for above radiation indicators in station soil samples is well below the permissible limit and hence cultivated soils at present do not pose any radiological risk.