Abstract
The control of working environment has been one of the most important duties for any companies to prevent occupational disease. In case of the controlled area using unsealed radioisotopes, measurement of the concentration of airborne radioactive material should be carried out. Then, we report the measurement performed at Tottori University and the results obtained from April 2004 to February 2006. As the results obtained from 3, 105 points, concentrations of radioactive material in all working places of 99% were below detection limit. Only 26 points were detected, but the maximum concentration levels were 0.036 of the limit.
