Monitoring the concentration of 238U, 232Th, 40K and 137Cs of soil in Anarak-Khour district, Central Iran

This study was conducted to determine the radioactivity concentration in soil samples of Anarak-Khour district located at central Iran. 48 soil samples from a depth of 10-15 cm were taken from seven different sites for monitoring. The radioactivity concentration of 238U, 232Th, 137Cs and 40K in soil samples was determined, using a high resolution (HPGe detector, p-type) γ-spectrometry by detectors with 55% and 38.5% relative efficiencies. The results showed that the radioactivity concentration ranged from 9.91 ± 0.11 to 4479.95 ± 0.15 Bq.kg-1 for 238U, from 5.95 ± 0.14 to 389.72 ± 0.10 Bq.kg-1 for 232Th, ≤MDA to 8.89 ± 0.13 Bq.kg-1 for 137Cs and from 123.18 ± 0.27 to 5201.42 ± 0.27 Bq.kg-1 for 40K in soil samples. The calculated internal and external hazard indices were more than 1 in some sites which showed a high dose for this area. These results could be used as a database of this area because it might be used as a nuclear waste site in the future.