Evaluation of Cancer Risks Associated with Radon Concentration Measured in the Science Faculty Building Complex Basement of a Tertiary Institution in South West, Nigeria

Abstract

In this study, radon concentration was measured with an active detector (RAD 7) in the Science Faculty building complex basement of a tertiary institution in South West (SW), Nigeria. The attendant risk descriptors were determined with the help of mathematical models. The range of mean detectable radon concentration in the basement is 26.5 ±12.3 – 242 ± 50.7 Bq m^-3 and the mean for all the rooms examined is 61.74 ± 58.48 Bq m^-3. The overall mean is less than the global mean of 100 Bq m^-3. The mean annual dose rate is found to be 0.97 ± 0.92 mSv y^-1.  The mean annual effective doses for different subjects examined are 0.412 ± 0.391 mSv y^-1 (worker), 0.0221 ± 0.0209 mSv y^-1 (student in lab session), 0.515 ± 0.488 mSv y^-1 (student who lives in the hostel) and 2.149 ± 2.036 mSv y^-1 (home owner). Students and workers in the basement are not likely to develop serious health effects, however, if the basement is used as a living room, the radon concentration in Room I-R might lead to health effects. The range of calculated excess life cancer risks (ELCRs) are (0.64-5.82) x 10^-3 and (1.16 -10.58) x 10^-3 for student and homeowner respectively. The mean values for the two subjects examined fall below the maximum risk of 3.5 x 10^-3.