Investigation of Background Gamma Radiation from Ceilings in Students’ Hostels and Offices at the University of Maiduguri, Northeastern Nigeria

摘要

Environmental radiation study forms a major aspect of radiation monitoring all over the world and Gamma radiation is the prime concern for radiation protection. Measurements of gamma radiation level were made using RADEYE PRD at selected Asbestos ceiling and non-asbestos (Gypsum) ceiling rooms in Block B and C of the Boys’ Hostels and New Faculty of Art Building respectively. Annual dose rate from each selected location was then estimated and the results show that gamma radiations from rooms with asbestos ceilings are generally higher than those from rooms with non-asbestos ceilings. The higher radiation around the asbestos ceiling is attributed to likely presence of primordial radionuclides of elements like 238 U, 232 Th and 40 K in the soil where the asbestos was mined. The highest annual effective dose rate due to gamma radiation in rooms with asbestos ceilings is estimated to be 0.91 mSv per year. This is considered to be very low and insignificant to cause any serious radiological problem to the students living in the Hostel. However, the only possible health risks from asbestos ceilings rooms might be due to the toxicity of the chemical constituents of asbestos rather than radiological risks from natural gamma radiation. The outcome of this research can be used in the compilation of background radiation map and radioelement mapping of Maiduguri which will be an integral part of the national background radiation and radioelement mapping of Nigeria.