Decontamination of 125I in a medical laboratory

摘要

A radiological laboratory for diagnoses was contaminated by 125I. A large-scale survey ofgamma-radiation has been made in different locations of the floors and walls of the lab to determine thecontaminated area and its activity. The activity level before decontamination for the wall and floor was 1400 and2000 Bq/cm2 respectively. Decontamination was carried out by using ethyl alcohol, potassium permanganate,ethylene diamine tetracetic acid and tissue papers. The decontamination factor has been calculated and it was175 and 200 for the wall and floor respectively. The D&D computer code has been used to calculate TotalEffective Dose Equivalent (TEDE). The TEDE from the wall and floor before decontamination were 3.05 and4.35 ( mSv/yr ) while after decontamination were 18 and 23 μSv/yr, respectively. These results are lower thanthe Egyptian and the international regulations (10 mSv/y for the public) according to International AtomicEnergy agency, IAEA, Safety Series, SS, no. 115 (1994).