External dose-rates for natural gamma emitters in soils from an agricultural land in West Anatolia

The surveys of natural gamma-emitting radionuclides in soils from three basins of West Anatolia intensively used for agricultural purposes were conducted during 1998-2003. In the present study, part of the survey, the activity concentrations of (238)U, (232)Th and (40)K in the soil samples from 43 sites distributed all over the agricultural land known as Buyuk Menderes basin were determined by scintillation gamma spectrometry. The average activity concentrations and ranges of the relevant radionuclides in the soils were as follows: (238)U was 29 (7-84); (232)Th, 22 (10-48) and (40)K, 464 (100-864) Bq kg(-1). The corresponding absorbed dose rates in air from all those radionuclides were in the range of 17-81 nGy h(-1) with a mean value of 46 nGy h(-1) and did not exceed the world-wide average values. All dosimetric calculations were performed based on the guidance of UNSCEAR 2000 report [1].