Determination of Pu in urine at ultratrace level by sector field inductively coupled plasma mass spectrometry

This whole body donation case (USTUR Registrant) involved a single acute inhalation of an acidic Pu(NO3)4 solution in the form of an aerosol 'mist'. Chelation treatment with intravenously (i.v.) Ca-EDTA was initiated on the day of the intake, and continued intermittently over 6 months. After 2.5 y with no further treatment, a course of i.v. Ca-DTPA was administered. A total of 400 measurements of 239+240Pu excreted in urine were recorded; starting on the first day (both before and during the initial Ca-EDTA chelation) and continuing for 37 y. This sampling included all intervals of chelation. In addition, 91 measurements of 239+240Pu-in-feces were recorded over this whole period. The Registrant died about 38 y after the intake, at age 79 y, with extensive carcinomatosis secondary to adenocarcinoma of the prostate gland. At autopsy, all major soft tissue organs were harvested for radiochemical analyses of their 238Pu, 239+240Pu and 241Am content. Also, all types of bone (comprising about half the skeleton) were harvested for radiochemical analyses, as well as samples of skin, subcutaneous fat and muscle. This comprehensive data set has been applied to derive 'chelation-enhanced' transfer rates in the ICRP Publication 67 plutonium biokinetic model, representing the behaviour of blood-borne and tissue-incorporated plutonium during intervals of therapy. The resulting model of the separate effects of i.v. Ca-EDTA and Ca-DTPA chelation shows that the therapy administered in this case succeeded in reducing substantially the long-term burden of plutonium in all body organs, except for the lungs. The calculated reductions in organ content at the time of death are approximately 40% for the liver, 60% for other soft tissues (muscle, skin, glands, etc.), 50% for the kidneys and 50% for the skeleton. Essentially, all of the substantial reduction in skeletal burden occurred in trabecular bone. This modelling exercise demonstrated that 3-y-delayed Ca-DTPA therapy was as effective as promptly administered Ca-EDTA.

Ustur whole body case 0269: demonstrating effectiveness of i.v. ca-dtpa for pu

Determination of 90Sr and Pu isotopes in contaminated groundwater samples by inductively coupled plasma mass spectrometry

The 2007 Recommendations (ICRP, 2007) introduced changes that affect the calculation of effective dose, and implied a revision of the dose coefficients for internal exposure, published previously in the Publication 30 series (ICRP, 1979a,b, 1980a, 1981, 1988) and Publication 68 (ICRP, 1994b). In addition, new data are now available that support an update of the radionuclide-specific information given in Publications 54 and 78 (ICRP, 1989a, 1997) for the design of monitoring programmes and retrospective assessment of occupational internal doses. Provision of new biokinetic models, dose coefficients, monitoring methods, and bioassay data was performed by Committee 2 and its task groups. A new series, the Occupational Intakes of Radionuclides (OIR) series, will replace the Publication 30 series and Publications 54, 68, and 78. OIR Part 1 (ICRP, 2015) describes the assessment of internal occupational exposure to radionuclides, biokinetic and dosimetric models, methods of individual and workplace monitoring, and general aspects of retrospective dose assessment. OIR Part 2 (ICRP, 2016), OIR Part 3 (ICRP, 2017), this current publication, and the final publication in the OIR series (OIR Part 5) provide data on individual elements and their radioisotopes, including information on chemical forms encountered in the workplace; a list of principal radioisotopes and their physical half-lives and decay modes; the parameter values of the reference biokinetic models; and data on monitoring techniques for the radioisotopes most commonly encountered in workplaces. Reviews of data on inhalation, ingestion, and systemic biokinetics are also provided for most of the elements. Dosimetric data provided in the printed publications of the OIR series include tables of committed effective dose per intake (Sv per Bq intake) for inhalation and ingestion, tables of committed effective dose per content (Sv per Bq measurement) for inhalation, and graphs of retention and excretion data per Bq intake for inhalation. These data are provided for all absorption types and for the most common isotope(s) of each element. The online electronic files that accompany the OIR series of publications contains a comprehensive set of committed effective and equivalent dose coefficients, committed effective dose per content functions, and reference bioassay functions. Data are provided for inhalation, ingestion, and direct input to blood. This fourth publication in the OIR series provides the above data for the following elements: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), actinium (Ac), protactinium (Pa), neptunium (Np), plutonium (Pu), americium (Am), curium (Cm), berkelium (Bk), californium (Cf), einsteinium (Es), and fermium (Fm).

ICRP Publication 141: Occupational Intakes of Radionuclides: Part 4.

Doses from intakes of radionuclides cannot be measured but must be assessed from monitoring, such as whole body counting or urinary excretion measurements. Such assessments require application of a biokinetic model and estimation of the exposure time, material properties, etc. Because of the variety of parameters involved, the results of such assessments may vary over a wide range, according to the skill and the experience of the assessor. The need for harmonisation of assessment procedures has been recognised in a research project carried out under the EU 5 th Framework Programme. The aim of the project IDEAS (partly funded by the European Commission under contract No. FIKR-CT2001-00160) was to develop general guidelines for assessments of intakes and internal doses from individual monitoring data. The IDEAS project started in October 2001 and ended in June 2005. To ensure that the guidelines are applicable to a wide range of practical situations, a database was compiled of cases of internal contamination that include monitoring data suitable for assessment. About 50 cases from the database were analized by different assessors, the results were collated, and differences in assumptions identified, with their effects on the assessed doses. From the results, and other investigations, draft guidelines were prepared, to provide a systematic procedure for estimating the required parameter values that are not part of the measurement data. A virtual workshop was held on the Internet, open to internal dosimetry professionals, to discuss the draft guidelines, which were revised accordingly. In collaboration with the IAEA, an intercomparison exercise on internal dose assessment was then conducted, which was also open to all involved in internal dosimetry. Six cases were developed and circulated with a copy of the revised guidelines, which participants were encouraged to follow, to test their applicability and effectiveness. The results were collated and a Workshop held to discuss the results with the participants. The guidelines were refined on the basis of the experience and discussion. The guidelines are based on a general philosophy of: • Harmonisation: by following the Guidelines any two assessors should obtain the same estimate of dose from a given data set. • Accuracy: the "best" estimate of dose should be obtained from the available data. • Proportionality: the effort applied to the evaluation should be proportionate to the dose - the lower the dose, the simpler the process should be. Following these principles, the Guidelines use the following "Levels of task" to structure the approach to an evaluation: Level 0: Annual dose 6 mSv). The guidelines provide: • Background information about the biokinetic models and the corresponding bioassay functions for the interpretation of monitoring data. • Detailed information about the handling and evaluation of monitoring data. • A structured approach to dose assessment consisting of a step-by-step procedure described in well-defined flowcharts with accompanying explanatory text.

/pdf/general-guidelines-for-the-estimation-of-committed-effective-3ueauhnvh5.pdf

General guidelines for the estimation of committed effective dose from incorporation monitoring data : (Project IDEAS - EU contract no. FIKR-CT2001-00160)

An analysis of 238Pu in the whole body donation to the U.S. Transuranium and Uranium Registries (USTUR) is presented. This donor accidentally inhaled an unusual physical form of plutonium, predominantly the 238Pu isotope in the form of a highly insoluble ceramic. Along with six other workers accidentally exposed at the same time, this donor excreted little or no 238Pu in his urine for several months. Subsequently, however, and, with no further intakes, the urinary excretion of 238Pu by all of these workers increased progressively. Such a pattern of increasing urinary excretion of plutonium resulting from a single acute inhalation was unknown at the time. The subject of this study provided a unique opportunity to analyze not only the pattern of urinary excretion for 17 y following this unusual intake but also the complete distribution of 238Pu in his donated body tissues and skeleton at death. Radiochemical analyses of tissues from this whole body donation were used to perform critical tests of the applicability and accuracy of the respiratory tract model and the systemic biokinetic models for plutonium currently recommended by the International Commission on Radiological Protection. The respiratory tract model was applied to analyze the donor's long-term urinary excretion pattern. The facility provided by this model to represent progressive transformation of insoluble particles in the lungs into a more soluble form, applied in conjunction with the systemic biokinetic model, predicted the total amount of 238Pu measured in the donor's body to within 17% accuracy. The measured division of 238Pu between the donor's lungs and systemic organs was predicted to within 10%. Small adjustments to several rate constants in these models provided precise predictions of the absolute amounts of 238Pu in the lungs, thoracic lymph nodes, liver, red bone marrow, skeleton (including the distribution of 238Pu between trabecular and cortical bone matrices derived from the radiochemical analyses), kidneys, testes, and muscle. The resulting individual-specific parameters were applied to evaluate the equivalent dose rates and cumulative doses received by the donor's organs and the overall effective dose. Whereas these individual modifications to the ICRP models provided a more accurate representation of the distribution of dose between the donor's organs, it was determined that the ICRP models provided an adequate estimate of the overall effective dose.

USTUR case 0259 whole body donation: a comprehensive test of the current ICRP models for the behavior of inhaled 238PuO2 ceramic particles. U.S. Transuranium and Uranium Registries.

R E Filipy

Papers

USTUR case 0259 whole body donation: a comprehensive test of the current ICRP models for the behavior of inhaled 238PuO2 ceramic particles. U.S. Transuranium and Uranium Registries.