Abstract

DETERMINATION OF RADIOACTIVITY CONCENTRATION OF NATURAL RADIONUCLIDES AND RADIATION HAZARD INDICES IN SOIL SAMPLES FROM OWERRI, SOUTH EAST NIGERIA.

*Omenikolo A.I., Odu D. A. and Amadi R.O.

Abstract

The determination of radioactivity concentration of natural radionuclides and radiation hazard indices in soil samples from three locations in Owerri, Nigeria was carried out. The levels of naturally occurring radioactivity in the soil samples were evaluated using Gamma Ray Spectrometry. The mean values obtained were 145.2 ± 3.6 (Bq.Kg-1), 12.5 ± 1.6(Bq.Kg-1) and 14.9 ± 0.6(Bq.Kg-1) for 40K, 238U and 232Th respectively. The Absorbed Dose Rate, External Hazard Index and Internal Hazard Index were evaluated using the activity concentrations of 40K, 238U and 232Th. The results showed that the mean value of radium equivalent activity is 45.0 Bq.Kg-1, while the values of absorbed dose rate and annual effective dose equivalent are 21.4nGy h-1 and 0.026mSvy-1 respectively. The values of external and internal health hazard indices are 0.12 and 0.15 respectively. The obtained values were less than the recommended safety limits of 51nGy.h-1 and 1Bq.kg-1. The study shows that the risk due to radiation contamination in the study area is low.

Keywords: Activity concentration, Dose, Uranium. Natural radioactivity, Radiological hazards.