Fallout241Am concentration in food and human tissue

AN ACCIDENT OF INTERNAL CONTAMINATION WITH PLUTONIUM AND AMERICIUM AT A NUCLEAR FACILITY IN JAPAN: A PRELIMINARY REPORT AND THE POSSIBILITY OF DTPA ADMINISTRATION ADDING TO THE DIAGNOSIS

This article introduces the first accident of internal contamination with plutonium (Pu) or americium (Am) in Japan for which treatment was carried out. An accident of internal contamination with Pu and Am occurred at a Pu research facility at Oarai-town of Ibaraki prefecture in Japan. A plastic bag containing these radionuclides ruptured when five workers were inspecting a storage container in a hood. As a consequence, these workers were internally contaminated with Pu and Am. Although contamination on the body surface was observed in all five workers, a positive nasal swab was detected in only three of them. A chelating agent, calcium diethylenetriaminepenta-acetate (CaDTPA), was administered to all of them including the two workers without a positive nasal swab. However, bioassay detected a significant amount of Pu and Am in urine after administration of DTPA in these two workers, whereas the levels of these nuclides were below minimum detectable levels in urine before the administration. Since the prevalence of adverse reactions in DTPAs is low, the present results suggest that administration of DTPA can be used for the diagnosis of internal contamination even when a nasal swab is negative or contamination around body orifices is not detected.

Validation of ICRP metabolic models for the transuranics in a Japanese population

Distributions of (239,240)Pu and 241Am in the tissues of Japanese were determined and then compared to those estimated using recent ICRP metabolic models. Intakes by inhalation and ingestion were calculated and used as input to the ICRP-30 model or a combination of the ICRP-66 lung model and the ICRP-67 metabolic model. The (239,240)Pu distribution in the lung, liver, skeleton, kidney, and muscle using the combination ICRP-66 and 67 models agreed well with the measured data. However, the measured plutonium concentration in the spleen was higher than predicted and than found in the kidney or muscle and indicates that the spleen should be treated as a separate organ in the ICRP model. The fractional uptake via ingestion of (239,240)Pu was estimated to be 11% with 5 x 10(-4) as the f1 value. The combination of ICRP-66 and 67 models were adequate descriptors of the organ burdens of 241Am measured in Akita and Niigata district populations. The 241Am ingrowth from 241Pu taken into in the human body contributes 90% of the measured burden.