Assessment of natural radioactivity levels in soil samples from Dejen district, Ethiopia

Gamma ray spectrometry was used to determine the activity concentrations of naturally occurring radionuclides in 12 soil samples collected at random from Dejen district, Ethiopia. In agricultural soils, the calculated mean activity concentrations of 226Ra, 232Th and 40K were 33.44 ± 2.01, 66.02 ± 4.54 and 214.16 ± 8.90 Bq kg-1, respectively, and in virgin soils, they were 38.05 ± 2.48, 61.78 ± 4.76 and 240.32 ± 10.79 Bq kg-1, respectively. The findings were discussed and compared to other studies' findings. The mean values of absorbed dose rate, annual effective dose rate and radium equivalent activity in agricultural land soils are 67.24 nGyh-1, 0.083 mSvy-1 and 144.57 Bq kg-1, and in virgin land soils are 67.53 nGyh-1, 0.082 mSvy-1 and 144.90 Bq kg-1, respectively. These findings were discussed and compared to the internationally recommended value. As a result, it is possible to conclude that the soil samples are safe for residents and those involved in agricultural activities.