Evaluation of natural radioactivity levels in soil and various foodstuffs from Delta Abyan, Yemen

Abstract

The main purpose of this study was to measure the natural radioactivity in some foodstuffs and agricultural soils from the Abyan Delta in Yemen and study the interaction between soil and foodstuffs by calculating the transfer factor (TF).The annual effective doses to individuals were also calculated and compared with the reference levels. The investigation yielded outcomes that can be considered as the initial phase in the computation of levels of radioactivity for a staple foodstuff in Yemen. The activity concentrations of Ra-226, Th-232 and K-40 were determined by using the high purity germanium (HPGe) gamma ray spectrometer. In agricultural soils, the mean activity concentrations of Ra-226, Th-232 and K-40 were 33.15 Bq kg(-1), 77.25 Bq kg(-1), and 1220.59 Bq kg(-1), respectively, while the maximum values in foodstuffs were 4.88 +/- 0.30, 2.50 +/- 0.14 and 351.30 +/- 11.25 (Bq kg(-1)), respectively. The average TF of Th-232 and K-40 were lower than the default values of 0.05 and 1.00 respectively, but the average TF value of Ra-226 was slightly higher than the reference value of 0.04. The average effective dose to individuals from the intake of the food types was 8.448 mu Sv y(-1), which is much lower than the worldwide average annual effective dose.