Characterization of Soil Radon Gas Concentrations in Parts of the Niger Delta Region

Radon is a naturally occurring radioactive noble gas generated from the decay of uranium-238 and radium-226 present in soils and rocks. Elevated radon concentrations in buildings and soil pose significant long-term inhalation health risks, particularly for lung cancer. This study characterizes soil radon gas concentrations at thirty measurement points across selected communities in Delta State and Bayelsa State in the Niger Delta South South geopolitical zone. Passive radon dosimeters using CR-39 nuclear track detectors were deployed at depths of 50 centimeters below ground surface and retrieved after 90 days of exposure. Track density analysis was performed using an optical microscope to derive radon concentration in units of Bq/m3. Geological and land use data were integrated with radon measurements to identify spatial concentration patterns. Results indicate soil radon concentrations ranging from 18 Bq/m3 to 310 Bq/m3, with the highest values associated with areas of oil exploration disturbance and geological fault zones. The study estimates potential indoor radon infiltration based on soil radon flux and building floor permeability. Risk assessment calculations indicate that communities near fractured geological formations require priority mitigation. Recommendations include sub-slab depressurization systems for newly constructed buildings and public health education campaigns for existing homeowners. Keywords: radon, nuclear track detector, Niger Delta, soil gas, radiation health risk