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.
