EVALUATION OF INDOOR AND OUTDOOR BACKGROUND IONIZING RADIATION OF SELECTED RESIDENTIAL BUILDINGS IN IBARAPA CENTRAL, OYO STATE, NIGERIA

Abstract

Indoor and Outdoor Ionizing radiation exposure levels were measured using a total of 10 randomly selected dwelling categorized as local and modern buildings in Ibarapa Central Local Government of Oyo State. All radiations were taken at the sample point for Indoor and Outdoor measurements by holding the survey meter at 1m above ground surface or floor to prevent unwanted effects of radiation from the soil or building floor. The detector was held at five meters away from the buildings nearby in order to avoid unwanted effect of the buildings materials on Outdoor measurements. Each measurement was repeated six times and the average was taken to represent the value for a sample point. The indoor exposure dose rate (0.27µSvh-1) is higher in local building than in modern building (0.23 µSvh-1) while the outdoor exposure dose rate (0.25 µSvh-1) is higher in modern building than in local building (0.23 µSvh-1). The result of all the location sampled revealed low exposure dose rate when compared with the average exposure dose rate (2.4mSvy-1 or 0.27 µSvh-1) according to international commission in Radiological protection (ICRP, 1990). It Can be concluded that there was no harmful ionizing radiation from the selected residential buildings in Ibarapa Central Local Government of Oyo State, Nigeria. It is recommended that regular and periodic monitoring of the background ionizing radiation level should be carried out to assess the health risks of the denizens of that area.