Assessment of Natural Background Radiation Exposure in the Federal Capital Territory of Nigeria

Abstract

The detrimental effects of environmental contamination and deterioration on health are a worldwide concern and Nigerian environmental and public authorities continue to be concerned about the risk to public health. The water, the sky, construction materials and the earth's crust all release natural background radiation that contaminates the environment around us. Additionally, people are exposed to background radiation that comes from internal, cosmic, and terrestrial sources, although, the altitude determines the amount of cosmic radiation exposure, and high altitudes result in large radiation doses. Monitoring the amounts of radiation to which humans are exposed, either directly or indirectly, requires an understanding of the natural background radiation in the environment. The current study attempted to create a baseline of outdoor background radiation in FCT for exposure rate, absorbed dose rate, annual effective dose equivalent, and excess life cancer risk. The study used a very sensitive survey meter to measure the BIR. The average BIR value found in the research areas is marginally below the 0.013mRh-1 global BIR level, indicating an almost high BIR level for the FCT while the absorbed dose rates of 105.85nGy/hr was greater than the 59nGy/hr global population weighted average gamma dose rates estimate. The obtained annual effective dosage equivalent value is greater than the global average normal annual effective dosage level for outdoor environments, and the excess lifetime cancer risk values were higher than the 0.29×10-3 allowable level as reported by UNSCEAR & ICRP. Therefore, the general people and those who live in environmentally sensitive areas may experience immediate health effects from contamination and radiation levels at the current rates.