Radioactivity concentrations and dose assessment for agricultural soil samples around the Jordanian petroleum refinery in Zarqa, Jordan

The activity concentrations of the natural radionuclides (238U, 232Th, 40K) in the agricultural soils around the Jordanian petroleum refinery in Zarqa city, Jordan, were investigated. The soil samples were collected from three different agricultural regions (X, Y and Z). The 232Th activity concentration was found to be too low in all samples. The average activity concentrations in Bq/kg were found to be: 40.1±1.6 for 238U and 372.6±11.9 for 40K in X-site, 38.3±1.9 for 238U and 486.4±15.0 for 40K in Y-site, and 45.4±1.3 for 238U and 313.3±11.1 for 40K in Z-site. Our findings are within the worldwide average values (UNSCEAR, 2000). The absorbed dose rates were calculated and found to be in the range of 20.86-47.62 nGy/h with an overall average value of 34.66 nGy/h. The average outdoor annual effective dose equivalent was estimated to be 41.13 ± 11.64 μSvy−1 which is below the world average of 70 μSvy−1.