The natural radionuclides present in sediments such as 226Ra, 232Th and 40K contribute to the amount of radiation in a large way, as most of the population is exposed to that radiation in those areas, and calculating the value of that radiation is of great importance in knowing the radiation that humans are exposed to by measuring that values with the world recommended values.
This study was conducted in order to measure the levels of natural radiation in sediments of the Tigris River in the city of Mosul, in northern Iraq, by using gamma spectroscopy technique to calculate the activity concentrations of natural radionuclides in the sediments, The results showed that the activity concentrations of 226Ra, 232Th, and 40K. ranged between (6.30±0.319-13.73±0.411) Bq.kg-1 and an average(9.86±0.385) Bq.kg-1 for 226Ra, and between (13.39±0.626-29.84±0.923) Bq.kg-1 and an average of (23.05±0.838) Bq.kg-1 for 232Th, while potassium-40 ranged between (166.83±6.456-275.96±7.601) Bq.kg-1 and with an average (232.91±6.456) Bq.kg-1 .And all the results of the activity concentration values were less than the internationally recommended values.
The radiation hazard indicators were calculated on according to the activity concentrations of those natural radionuclides in the studied areas. And it was found that the value of the effectiveness of the radium equivalent was between (38.52-71.96) Bq.kg-1 and an average of (60.76) Bq.kg-1, which is less than the internationally recommended value, which should not exceed (370) Bq.kg-1,As for the value of the absorbed dose percentage Dɣ, it ranged between (17.81-33.07) nGy.h-1 and an average of (28.16) nGy.h-1