Background Gamma Radiation Measurement Of Market Places In Keffi, Nasarawa State, Nigeria.

In this study, the assessement of background gamma radiation measurement of market places in Keffi Nasarawa State, Nigeria has been conducted. An in-situ measurement of background gamma exposure rate count per minute for twenty locations from two market (ten measurement each) was done using a well calibrated portable halogen-quenched Geiger Muller (GM) detector (Inspector alert nuclear radiation monitor SN: 3544) at an elevation of 1.0 m above ground level with a Global Positioning System (GPS) for geographical locations. Using an established radiological relations, the radiological health hazards were evaluated using the measured background gamma exposure rates. The values obtained were compared with recommended limits set by ICRP and UNSCEAR to ascertain the radiological hazard status of the environment. The mean values of the background gamma exposure levels (0.0869 mRh'1), absorbed dose rates (756.03 nGyh'1) and excess lifetime cancer risk (3.245x 1 O'3) are higher than their recommended safe limits of 0.013 mRh'1, 84.0 nGyh'1, 0.29x10’3 respectively as recommended by UNSCEAR and ICRP. The mean Annual Effective Dose Equivalent (AEDE) (0.927 raSvy'1) is lower than the recommended permissible limits of 1.00 mSvy'1 for general public exposure and also the effective doses to different body f organs are all below the recommended limits of 1.0 mSvy'1. Generally, the study shows that market places • in Keffi, Nasarawa State is relatively safe radiologically with little contamination which could be attributed C to the to human activity and partly due to geological formation of the market places. However, the contamination will not pose any immediate radiological health effect on resident of the area but there is tendency for long-term health hazards in the future such as cancer due to doses accumulated.