Health physics of an acute overexposure to a radiography source

An outline account is given of the results of an accident to a 6,7 Ci 192Ir-source which fell out of its container on 8 January 1977 at a South African construction site. Due to a faulty monitor, the accident was not noticed by the radiographer and 3 hours later a construction supervisor picked up the source and put it in the left breast pocket of his shirt, where it remained for approximately 2h 40min. Local reactions of the main subject included an erythema of the left hand, leading to amputation of the index and middle fingers after 24 months. The estimated dose equivalent was over 5000 rads. Erythema of the chest wall also developed, leading to excision of the necrotic area and pedicle skin graft 18 months after the incident. Using the Strandquist method, the central necrotic part was estimated to have received between 5000 and 10,000 rad, the adjoining area between 1000 and 2,250 rad. This was in remarkable agreement with the physical calculations, especially since the source was not stationary. (U.K.)