Natural radioactivity measurements in agricultural soil, fertilizer and crops in some specific areas of Kingdom of Saudi Arabia

Abstract

Abstract High Purity Germanium (HPGe) detector gamma-ray spectrometry with 500 cc Marinelli beaker geometry was used for radioactivity measurement in some specific areas of Kingdom of Saudi Arabia (KSA). The detection limits of 210Pb, 238U, 226Ra, 232Th and 40K in soil, fertilizers, and vegetables lie mostly below 1 Bq/kg. The activity concentrations of 238U and 226Ra in local phosphate fertilizers were measured in the range of 236.8–879.0 Bq/kg and 101.5–297.0 Bq/kg, respectively. The respective activity concentrations of 238U and 226Ra measured in one charge of German phosphate fertilizer are in the range of 552.7–790.0 Bq/kg and 280.6–317.0 Bq/kg. The activity concentrations of 232Th are assessed to have maximum values up to 2.24 Bq/kg in locally manufactured phosphate fertilizers. Local urea exhibited concentration level (Bq/kg) of 210Pb, 238U, 226Ra, 232Th and 40K below the detection limit. Mean values of activity concentrations of 238U in agricultural soil of Wadi Fatima, Taif, Hada Al-Sham, Madina City and Abyar Al-MashiMadina are 21.7 ± 3.24, 38.2 ± 4.1, 17.6 ± 2.1, 34.3 ± 3.5 and 32.7 ± 2.4 Bq/kg, respectively. The respective mean of 226Ra activity concentrations in those areas are 12.16 ± 1.16, 20.2 ± 1.33, 11.21 ± 0.4, 21.4 ± 1.7 and 21.0 ± 1.22 Bq/kg. The specific activity of 232Th in the respective areas has been measured as 12.6 ± 1.3, 25.3 ± 0.8, 11.5 ± 0.9, 20.4 ± 2.4 and 20.0 ± 1.2 Bq/kg. Activity concentrations of 210Pb, 238U, 226Ra and 232Th in the vegetable samples are mostly found in the range of 0.37 Bq/kg to 37.8 Bq/kg. The 40K specific activity lies in the range of 44.4–196 Bq/kg. The calculated absorbed dose rates in the representative locations are 24.07–53.28 nGy/h.