Intake and subsequent fate of a ceramic particle containing 2.85 microCi 241Am: a case study

Intake of 241Am was reported in a young female technologist. External monitoring, whole body counting, urinalysis and fecal analysis were performed to determine the subsequent fate of the contaminant. Five days later, more than 99.5% of the radioactivity was voided in a fecal sample. A single particle, containing 2.85 microCi of 241AmO2 incorporated in a ceramic matrix, was isolated from the fecal sample. Brief descriptions of the radioanalytical results and dosimetry implications are presented. A shadow shield whole body counter was conveniently used to make an early estimate of the intake. This initial estimate enabled staff to decide that it was not necessary to artifically remove the contaminant. It was estimated that the lower large intestine was the organ which received the highest dose due to the passage of the ceramic particle. Systemic uptake of 241Am was indicated by urinalysis. The fractional transfer of 241Am from the GI tract to the blood was estimated to be less than 6 X 10(-5). This maximum estimate is limited by the MDA of the analytical procedures used. The fractional transfer of the 241Am from the GI tract to blood in this case is about an order of magnitude less than recent ICRP recommendations for "all compounds of americium".