Elevated background ionizing radiation has its health effects on people who reside in such areas, this necessitate the need for constant monitoring. The activity concentrations of K40, Th-232 and U-238 were measured in three different selected study areas in Ota using RS230 gamma spectrometer. The highest activity concentrations for the three radionuclides were
recorded in the Industrial Estate. The mean dose rate recorded was 45.37 nGyh-1 , 37.12 nGyh-1 and 33.33 nGyh-1
for Industrial Estate, Obasanjo Estate and Atan respectively. The mean outdoor annual equivalent dose estimated was 0.056 mSvy-1 , 0.045 mSvy-1 and 0.041 mSvy-1 respectively for the three locations. The estimated excess lifetime cancer risk ranged from 0.14 x 10-3 – 0.277 x 10-3 for the study areas. The radiological variables estimated in this study were all within world average recommended limit. The study concluded that the locations considered in this work are safe for dwellers and that industrial activity has influence on the background radiation
