HEALTH RISK ASSOCIATED WITH BACKGROUND RADIATION

ABSTRACT This study assessed the background ionizing radiation (BIR) levels at 10 chosen indoor and outdoor sites at the University of Delta, Agbor, Nigeria, using a portable Model S-1 Radiation Detector. Measurements concentrated on indoor and outdoor absorbed dose rates (ADR), annual effective dose equivalent (AEDE), and excess lifetime cancer risk (ELCR). Indoor ADR values ranged from 0.010 to 0.081 µSv/hr, with the Faculty of Environmental Science recording the highest level, slightly below the UNSCEAR global indoor reference limit. Outdoor ADR values varied between 0.013 and 0.065 µSv/h, with the Faculty of Education showing the highest value, but still within the IAEA-recommended safety threshold. Calculated AEDE and ELCR values for both indoor and outdoor locations also remained below internationally accepted safety limits. However, locations such as the Faculty of Environmental Science, the Faculty of Law, and the Faculty of Education exhibited relatively higher values compared to other areas on campus. These elevated values are likely linked to local soil composition, building materials, and environmental factors. Overall, the findings indicate that both indoor and outdoor gamma radiation levels across the university remain within safe exposure limits, posing no significant radiological health risks to students, staff, or visitors. However, periodic monitoring is recommended, especially for locations with comparatively higher radiation levels.