Transfer factors for natural radioactivity into date palm pits

Palm pits are used in various human and animal feed products. In this study, the natural radioactivity levels from soil and date palm pits of 9 samples collected from major date palm farms in three different regions (Buraidah, Al-Zulfi and Al-Majmaah) of Saudi Arabia were determined by using the high purity germanium (HPGe) gamma-ray spectrometer. The mean activity concentrations of 226Ra, 232Th, 137Cs and 40K in soil samples were 12.8 ± 2.2, 10.2 ± 2.1, 0.28 ± 0.10 and 329 ± 87 Bg kg−1, respectively. Similarly the mean activity concentrations of 226Ra, 232Th, and 40K in date palm pits were 5.6 ± 1.2, 2.8 ± 0.4 and 181 ± 17 Bq kg−1, respectively, whereas 137Cs could not be detected. The geometric mean of TF values (geometric standard deviation in parentheses) of 226Ra, 232Th, and 40K were 0.33 (2.1), 0.22 (1.8) and 0.51 (2.0), respectively.