Abstract
Radium contamination had built up in a large office building over a period of forty years. The radiation levels were as high as 500 mrem/hr with alpha contamination >40,000 d/m/100 cm2. From an industrial hygiene point of view, the major problems associated with the decontamination of the facility were: (1) keeping from tracking contamination into clean areas, (2) keeping the workers from becoming contaminated, (3) keeping the workers' exposure to external ionizing radiation as low as possible, (4) keeping inhalation and/or ingestion of radium from occurring, and (5) keeping future inhabitants of the building from receiving any radiation exposure as a result of their working in the building. The building was decontaminated to a maximum of 0.2 mr/hr at a distance of one foot from any surface and the radon plus its daughter's activity was reduced to levels of less than 10−9 μc/ce.