Soil-gas and Indoor Radon Measurement for Cancer Mitigation in Nigeria Tertiary Institutions Using Higher Institutions in Ibadan as a Case Study

Radon – a Radiologically Hazardous Gas Generated Within Bedrocks, Capable of Building Up in Confined Spaces, Has Been Identified as a Major Cause of Lung Cancer After Smoking. Lack of Information, Awareness and Data on Spatial Radon Variability in Africa and Most Especially in Nigeria Has Hindered Effective Mitigation Measures. Staff and Students of Tertiary Institutions Are Exposed to Radon Gas Emanating from the Bedrocks on Which the Institutions Are Sited. This Study Was Designed to Measure Soil-gas and Indoor Radon in Six Tertiary Institutions in Ibadan Towards Effective Radon Mitigation. Indoor Radon Concentration Was Measured in a Total of 42 Selected Ground Level Offices and 60 Classrooms While 220 Soil-gas Radon Concentration Measurements Were Carried Out Using Rad7. Indoor Radon Concentrations for the 60 Classrooms Had a Range of 29.41 – 156.73 Bqm-3 With an Average Value of 69.58 ± 23.67 Bqm-3 While That for Offices Had a Range of 37.82 Bqm-3 to 234.52 Bqm-3 With a Mean Value of 95.42 ± 36.82bqm-3. 21.72% of Sampled Offices Had Radon Concentration Values Above the 100 Bqm-3 Limit Set by World Health Organization for Indoor Radon. Soil Gas Radon Concentration Had a Range of 0.46 - 43.249 Kbqm-3 and Mean Value of 9.69 ± 3.72 Kbqm-3. With 21.36% of Sites Above 10 Kbqm-3, Tertiary Institutions in Ibadan, Based on Akerblom Classification Are Mainly Under Low Level of Soil-gas Radon Infiltration. A Positive Correlation (R2 = 0.67) Was Observed Between the Indoor Radon and Soil-gas Radon. Sites on Granitic Lithology Presented the Highest Mean Soil-gas Radon Concentration