The study conducted in the northwest region of Jordan aimed to assess the levels of natural radioactivity in soil and olive mill pomace (OMP) samples. The researchers used Nal (TI) gamma -ray spectrometry to measure the activity concentrations of 226 Ra, 232 Th, 40 K, and 137 Cs in the samples. The average activity concentrations of 226 Ra, 232 Th, 40 K, and 137 Cs in the soil samples were found to be 18.624 +/- 5.82, 12.276 +/- 5.728, 518.33 +/- 212.57, and 0.140 +/- 0.09 ( Bq , kg -1 ), respectively. In the OMP samples, the average activity concentrations of 226 Ra, 232 Th, and 40 K were 7.272 +/- 4.386, 3.454 +/- 1.503, and 169.997 +/- 81.873 ( Bq kg -1 ), respectively, and no 137 Cs was detected. The study also investigated fundamental parameters associated with radon, specifically the radon emanation coefficient ( Rn EC ) and radon mass exhalation rate ( E x ). The Rn EC values ranged from 0.621 to 0.78 ( Bq kg -1 ), with an average value of 0.71 +/- 0.06 ( Bq kg -1 ). The estimated E x from the soil samples ranged from 65.83 to 124.86 ( mBq kg -1 h -1 ), with an average value of 99.74 +/- 21.73 ( mBq kg -1 h -1 ). Regarding radiological hazards, the study examined various parameters, including radium equivalent activity, external and internal hazard indices, gamma and alpha indices, absorbed gamma dose rate, and excess lifetime cancer risk. All of these assessed values were found to be below the worldwide recommended limits for radiological safety. Additionally, the study analyzed the concentrations of gross alpha and gross beta radioactivities in soil and OMP samples. The soil samples had an average gross alpha activity of 4.642 +/- 1.04 ( Bq kg -1 ) and an average gross beta activity of 48.13 +/- 14.50 ( Bq kg -1 ). The OMP samples showed an average gross alpha activity of 0.32 +/- 0.27 ( Bq kg -1 ) and an average gross beta activity of 59.19 +/- 12.94 ( Bq kg -1 ). Overall, the obtained results are crucial for evaluating the radiological risks associated with natural radioactivity in the northwest region of Jordan. The findings establish baseline data for comparison and reference for radioactivity levels in the environment.
