Indoor and Outdoor Background Radiation Levels and Radiological Hazard Assessment of Some Modern Houses in Keffi Metropolis, Nasarawa State, Nigeria

In this study, the radiological hazard indices due to radiation exposure of some modern houses in Keffi, Nasarawa State were investigated. An in -situ measurements of the exposure level were made using Radex radiation meter model RD 1212. The radiological hazards indices evaluated were absorbed dose rate (ADR), outdoor annual effective dose rate and the excess cancer lifetime risk. The mean exposure obtained for the modern houses and its surroundings ranged betxveen 0.05 to 0.09 pSv/h and the corresponding calculated ADR ranged between 0.088 to 0.158mSv/yr, while the calculated outdoor AEDR is 6.13 x 10-5 to 1.10 x KNmSv/yr. The estimated excess lifetime cancer risk due to gamma radiation at the modem houses and its environment is ranged between 2.15 x 10-4 to 3.86 x 10-4. The results show that the modern houses and their sunoundings within Keffi metropolis of Nasarawa State cannot pose any risk as the annual effective dose rate is below the acceptable dose limit of lmSv/yr for the public and the excess lifetime cancer risk from the houses was below the 0.3mSv/yr. Tins indicates that the building materials that were used may not pose any significant radiation hazard to the people.