ASSESSMENT OF RADIATION CONCENTRATIONS IN HARAMAYA UNIVERSITY, HARAR AND DIRE DAWA

Abstract

Assessment of radiation concentration in buildings was carried out at three locations, HU campus, Harar town and Dire Dawa town. The instruments used to collect data were Electronic personal dosimetery (EPD model type MINI-6100). In this study, data of EPD were used to estimate average net radiation from buildings. New, intermediate and old buildings were selected at the three locations. However, four rooms in each building were randomly selected making a total sample of 36 rooms for the three locations and radiation was measured interior and exterior the rooms up to four (4) meter distance from the walls to the center, at distance interval of 0.5 m and background radiation were always measured outside, far from any building at a height of 1m above the ground. The results show that the doses absorbed by inhabitants from the nine buildings at the three locations never exceeded the public limit, even for those buildings that showed net positive radiations. Negative results indicated higher background radiations than radiation measured from the interior and exterior of rooms. IAEA recommends 114nSv/h (1mSv/y) as an appropriate dosimetery reference level for radon exposure. According to IAEA, all results were below the standard radiation dose limit. The result of this study indicate that people living and working in old, intermediate and new buildings of the three areas were safer and are not exposed to high doses of radiation. Intermediate buildings were safer than old and new buildings. No differences were observed between indoor and outdoor radiations. More study is recommended as far as building materials are concerned.