RESUMO
Human is exposed to radiation in their environment with or without their consent; and the exposure to natural background radiation is an unpreventable event on earth. An in situ assessment of the indoor and outdoor background radiation in Akwanga and Keffi towns of Nasarawa state Nigeria was carried out using a halogen-quenched Geiger Muller [GM] detector [Inspector alert Nuclear radiation monitor SN: 3544]. Each of these towns was divided into at least 20 sampling areas where at least ten readings were taken in order to have a reliable data. The mean indoor and outdoor annual effective dose of Akwanga were 1.29 +/- 0.13mSv/yr and 0.31 +/- 0.04 mSv/yr respectively; and that of Keffi were 1.08 +/- 0.15mSv/yr and 0.25 +/- 0.04 mSv/yr respectively. The radiation levels in both highly populated towns were found to be within the safe limit for areas of normal background set by UNSCEAR [2.4 mSv/yr]. These results would serve as a baseline upon which other exposures would be assessed and in the future, serve as reference for dosimetry and decontamination in situations of radiation poisoning of these towns