RADIATION MAPPING OF OYO STATE, SOUTHWESTERN NIGERIA

Abstract

Exposure of human beings to radiation cannot be measured or quantified by human senses. These radiations differ in their hardness and ability to penetrate materials. The implications of radiation on human body include biological, acute, generic and somatic effects. The studies comprehensively determine ambient ionizing radiation and also took inventory of the spatial distribution of ambient ionizing radiation in Oyo State. Exposure rate was measured at 1m above the ground level with the use of a Geiger-Müller-counter, at positions measured by Global Positioning System (GPS). About one hundred and twenty (120) towns and villages were visited taking from three to five towns in each of the thirty-three local government areas of the state. The collected data was super-imposed on a digital map of Oyo State to produce the isodose map, elevation map, and the mean dose map to identify areas of elevated risks of ambient ionizing radiation in the study using ARCGISTM & SURFERTM software. Results indicate that areas like Saki East and West, Irepo, Orelope, Olorunsogo and Ori Ire local governments had higher exposure rate with dose range of 0.34-0.38 μSv/hr while areas like Oluyole, Iddo, Iseyin, Ona Ara, Lagelu, Itesiwaju, Oyo East and West local governments and all the local governments in Ibadan axes had lower exposure rate with dose range of 0.12-0.20 μSv/hr. People living in areas identified with high background radiation levels in this study should therefore be made aware of the potential radiation related health problems, while government should also do more to stop the common practice of using mine wastes for foundation fillings and block construction because of the radiological i