Assessment of Indoor and Outdoor Environments Ionizing Radiation Exposure Levels at Fourah Bay College Laboratories and Workshops, University of Sierra Leone

This study was an attempt to assess indoor and outdoor radiation equivalent dose rates in six laboratories and four workshops at Fourah Bay College, University of Sierra Leone in order to determine corresponding Annual Effective Dose Equivalent (AEDE) and assess the Excess Life-time Cancer Risk (ELCR) of students, staff and other users of the laboratories, workshops and their immediate neighborhood. The average values recorded for the indoor and outdoor equivalent dose rate, AEDE and ELCR are (0.20 µSv/h and 0.10 µSv/h), 1.40 mSv/y and 0.18 mSv/y) and ( respectively while the average ratio of indoor to outdoor equivalent dose rate observed was . These average values are lower when compared with the global average limits of 2.4 mSv/y for indoor exposure, and 1.0 mSv/y for outdoor exposure, established by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and the International Commission on Radiological Protection (ICRP) respectively. The maximum values of Indoor Equivalent Dose Rates, AEDE and ELCR were recorded in the Nuclear Science and Physics laboratories, both significantly higher than the recommended limits by UNSCEAR and ICRP. This indicates potential health risks for staff and students spending prolonged periods in these environments. Generally, the study shows that Fourah Bay College is relatively safe radiologically with little contamination which could be attributed to the artificial radiation sources (radioactive isotopes, particle accelerators and nuclear reactors) found in the nuclear science and physics laboratories and also due to the poor ventilation system in the nuclear science laboratory. However, the contamination will not pose any immediate radiological health effect on students and staff in the college but there is tendency for long-term hazards in the future such as cancer due to doses accumulated. It is therefore recommended that regular radiation monitoring exercise should be conducted from time to time in order to checkmate both the workers and students from high radiation exposure.