MEASUREMENT AND ASSESSMENT OF INDOOR AND OUTDOOR AMBIENT RADIATION LEVELS AT THE TAKE-OFF SITE
ABSTRACT
Harmful background radiation in our environment has been identified as one of the primary causes of various ailments such as cancer and tumors in our society today. These Higher radiation levels are emitted from igneous rocks such as granite rocks and soil formed from the weathering of these rocks as well as Radon gas in the atmosphere while lower radiation levels are usually associated with sedimentary rocks. This research project is aimed at the measurement and assessment of ambient indoor and outdoor radiation levels at the take-off site of Federal University Dutsin-Ma to ascertain the amount of ionizing radiation present. The indoor and outdoor radiation levels were measured in thirty-six (36) buildings, some road pavements and outdoor sports facilities are also considered using a digital radiation detector (Radiation Alert Inspector). While taking measurement readings, the radiation meter was held one meter above the ground oriented vertically upward. For each location, ten readings were taken, five indoors and five outdoors. From the results obtained, it was observed that the old Biology and Biochemistry laboratories were found to have the highest value of indoor annual equivalent dose rate of 2.27±0.29 mSv/yr and 2.27±0.33 mSv/yr respectively, while the lowest value for indoor annual equivalent dose rate was recorded as 0.85±0.22 mSv/yr at Lecture Halls 3 and 4. The highest outdoor annual equivalent dose rate was recorded at new Physics laboratory as 0.46±0.10 mSv/yr while the lowest outdoor annual equivalent dose was recorded at the recreational building as 0.23±0.03 mSv/yr. The overall average indoor and outdoor annual equivalent dose rates on the take-off site of FUDMA were computed and found to be 1.41±0.29 mSv/yr and 0.33±0.08 mSv/yr respectively. A comparison of these results with the worldwide average limit of equivalent dose rate of 2.4 mSv/yr recommended by the International Commission on Radiation Protection (ICRP, 1990) for protection of human beings from ionizing radiation, infers that the ambient indoor and outdoor radiation levels at the take-off site of FUDMA are within the safety limits. It is recommended that a further research should be carried out during the dry and rainy season using different radiation detectors and qualitative elemental analysis of the air, soil, water rocks and water be carried out so as to determine the actual radionuclides responsible for the levels of ambient radiation on the take-off campus of Federal University Dutsin-Ma.
