Assessment of Terrestrial Gamma Radiations Doses Rates and its associated Hazards in Taraba State, Nigeria

Abstract Radioactivity distributions in the ambient air of Taraba State and their corresponding radiological health effects were assessed with respect to geological formations of the state. The radioactivity assessment was done using handheld radiation survey meter - Compact Gamma Surveyor by GF Instruments. The terrestrial gamma radiation dose (TGRD) rates in the state varied from \(\:1.59\:to\:8467.03\:nGy{h}⁻¹\) with overall average value of \(\:107.81\:±\:13.22\:nGy{h}⁻¹\). The average TGRD rates in UBG (undifferentiated basement complex and granitoid) and BSS (Bima sandstone) formations of the state were \(\:143.56\:±\:21.52\:nGy{h}⁻¹\) and \(\:70.63\:±\:1.67\:nGy{h}⁻¹\) respectively, while it was below the world recommended average of \(\:59.0\:nGy{h}⁻¹\) in other formations. The estimated radiological health hazards due to the presence of TGRD rates in the state revealed the average annual outdoor effective dose rates and excess lifetime cancer risk in the entire Taraba state were \(\:0.13\:±\:0.02\:mSv{y}⁻¹\) and \(\:0.46\:±\:0.06\:mSv\) respectively, which are higher than the world recommended average values of \(\:0.07\:mSv{y}⁻¹\) and \(\:0.29\:×\:\:{10}⁻³\) respectively. Meanwhile, isodose map of the state revealed that the regions affected by the high elevated TGRD rates above the world average TGRD rates in the state were around Yorro, Zing, Lau, Jalingo, Wukari, Donga and Saraduna local government areas of the state. This indicates that people residing within these locations of the state were exposed to high TGRD rates capable of causing health challenges on them. This implies that inhabitants within the regions of high elevated TGRD rates of the state have high probability of developing radiation related cancers during their lifetime, assuming they spent their lifetime in the state.