Uranium content and dose assessment for phosphate fertiliser and soil samples: comparison of uranium concentration between virgin soil and fertilised soil.

Specific activity of (235)U and (238)U in soil and fertiliser samples from Guellal region in Setif (Algeria) was determined by gamma-ray spectrometry. The selected phosphate fertilisers samples were collected from two types of fertilisers NPK (N, nitrogen; P, phosphorus; K, potassium) and NPKs (sulphate-based NPK). These last ones are used to fertilise the studied area as well as a radioactivity comparison between the soils before and after fertilisation. NPK and NPKs fertilisers have presented higher concentrations of the radionuclide (238)U, up to 1125 and 1545 Bq kg(-1), respectively. For soils before and after fertilisation, the concentrations of (238)U were, respectively, 252.8 and 316.2 Bq kg(-1). The average value and range of measured concentration of (235)U for soils before fertilisation was 12.16 ± 1.4 Bq kg(-1) and for the fertilised soils was 15.16 ± 1.8 Bq kg(-1), whereas the corresponding values for NPK and NPKs fertilisers were, respectively, 49.38 ± 5.7 and 50.61 ± 5.2 Bq kg(-1).