Determination of radon gas risk indices in soil on fractured basement of Ayetoro Housing Scheme, Oyo.

Radon gas, a naturally occurring radioactive element, presents significant health risks, particularly in areas with fractured basement geology, where subsurface characteristics can elevate its concentration. As the second leading cause of lung cancer globally, after smoking, radon exposure is a critical public health concern. This study investigates radon gas risk indices in soil and groundwater within the fractured basement of the Ayetoro Housing Scheme in Oyo, Nigeria. Thirty soil samples were collected from various locations within the study area, categorized into competent, moderate, and incompetent zones based on fracture intensity, using GPS for precise location mapping. Radon concentrations in soil were measured using a RAD7 radon detector. The data were analyzed based on soil radon concentrations using descriptive and inferential statistics, revealing significant variation across lithologies and elevated levels in fractured zones. The highest concentrations were found in mica schist, granite gneiss, and migmatite, with incompetent zones having the highest risk indices.