Development of the occupational exposure during the production and application of radiopharmaceuticals in Germany.

An increasing number of radiopharmaceuticals and proteins are available for diagnosing and treating various diseases. The demand for existing and newly developed pharmaceutical radionuclides and proteins is steadily increasing. The radiation exposure levels of workers in the radiopharmaceutical industry and nuclear medicine field are closely monitored, specifically their effective dose and equivalent dose, leading to the question, of whether the dawn of radiopharmaceuticals affects the occupational exposure level.

Effect of blood activity on dosimetric calculations for radiopharmaceuticals.

The objective of this work was to investigate the influence of the definition of blood as a distinct source on organ doses, associated with the administration of a novel radiopharmaceutical for positron emission tomography-computed tomography (PET/CT) imaging-(S)-4-(3-F-fluoropropyl)-L-glutamic acid (F-FSPG). Personalised pharmacokinetic models were constructed based on clinical PET/CT images from five healthy volunteers and blood samples from four of them. Following an identifiability analysis of the developed compartmental models, person-specific model parameters were estimated using the commercial program SAAM II.

Uncertainty Quantification in Internal Dose Calculations for Seven Selected Radiopharmaceuticals.

Unlabelled: Dose coefficients of radiopharmaceuticals have been published by the International Commission on Radiological Protection (ICRP) and the MIRD Committee but without information concerning uncertainties. The uncertainty information of dose coefficients is important, for example, to compare alternative diagnostic methods and choose the method that causes the lowest patient exposure with appropriate and comparable diagnostic quality. For the study presented here, an uncertainty analysis method was developed and used to calculate the uncertainty of the internal doses of 7 common radiopharmaceuticals.

Estimating the absorption of soil-derived uranium in humans.

The aim of the present study was to improve the estimation of soil-derived uranium absorption in humans. For this purpose, an in vitro solubility assay was combined with a human study by using a specific edible soil low in uranium. The mean bioaccessibility of the soil-derived uranium, determined by the solubility assay in artificial gastrointestinal fluid, was found to be 7.

The dynamic range of the human metabolome revealed by challenges.

Metabolic challenge protocols, such as the oral glucose tolerance test, can uncover early alterations in metabolism preceding chronic diseases. Nevertheless, most metabolomics data accessible today reflect the fasting state. To analyze the dynamics of the human metabolome in response to environmental stimuli, we submitted 15 young healthy male volunteers to a highly controlled 4 d challenge protocol, including 36 h fasting, oral glucose and lipid tests, liquid test meals, physical exercise, and cold stress.

Reliability of a new biokinetic model of zirconium in internal dosimetry: part II, parameter sensitivity analysis.

The reliability of biokinetic models is essential for the assessment of internal doses and a radiation risk analysis for the public and occupational workers exposed to radionuclides. In the present study, a method for assessing the reliability of biokinetic models by means of uncertainty and sensitivity analysis was developed. In the first part of the paper, the parameter uncertainty was analyzed for two biokinetic models of zirconium (Zr); one was reported by the International Commission on Radiological Protection (ICRP), and one was developed at the Helmholtz Zentrum München-German Research Center for Environmental Health (HMGU).

Reliability of a new biokinetic model of zirconium in internal dosimetry: part I, parameter uncertainty analysis.

The reliability of biokinetic models is essential in internal dose assessments and radiation risk analysis for the public, occupational workers, and patients exposed to radionuclides. In this paper, a method for assessing the reliability of biokinetic models by means of uncertainty and sensitivity analysis was developed. The paper is divided into two parts.

Daily urinary excretion of uranium in members of the public of Southwest Nigeria.

The main aim of this study was to determine and evaluate urinary excretion values of uranium in members of the public of Southwest Nigeria living in areas of low environmental uranium. As several uranium mines are running in Nigeria and the operations could be a risk of contamination for the workers as well as for the members of the public, biomonitoring of urine could provide information about the exposure to uranium for the subjects. Therefore, baseline values of uranium in urine are needed from subjects living in areas without mining activities.

Human biokinetic data and a new compartmental model of zirconium--a tracer study with enriched stable isotopes.

Biokinetic models describing the uptake, distribution and excretion of trace elements are an essential tool in nutrition, toxicology, or internal dosimetry of radionuclides. Zirconium, especially its radioisotope (95)Zr, is relevant to radiation protection due to its production in uranium fission and neutron activation of nuclear fuel cladding material. We present a comprehensive set of human data from a tracer study with stable isotopes of zirconium.

Measuring technique for thermal ionisation mass spectrometry of human tracer kinetic study with stable cerium isotopes.

Thermal ionisation mass spectrometry (TIMS) method has been developed for the simultaneous detection of different cerium isotopes in biological samples (i.e., blood and urine) at very low concentrations.

Solubility of uranium and thorium from a healing earth in synthetic gut fluids: a case study for use in dose assessments.

The aim of this case study was to estimate the bioaccessibility of uranium ((238)U) and thorium ((232)Th) from a healing earth by analysing the solubility of these radionuclides in synthetic gastric and intestinal fluids. An easy applicable in vitro test system was used to investigate the fractional mobilization of the soil contaminants being potentially available for absorption under human in vivo conditions. These findings provided the basis for a prospective dose assessment.

Measurement of cerium in human breast milk and blood samples.

The aim of this study was to evaluate the relationship between cerium content in human breast milk and blood plasma or serum. Blood samples and breast milk at various stages of lactation, from 5 days to 51 weeks post partum, were donated by 42 healthy breast-feeding mothers from Munich, Germany and by 26 lactating Spanish mothers from Madrid at 4 weeks post partum. Inductively coupled plasma mass spectrometry was applied for the determination of cerium in the biological samples.

Radiation dose assessment of exposure to depleted uranium.

Depleted uranium (DU) is claimed to contribute to human health problems, known as the Gulf War Syndrome and the Balkan Syndrome. Quantitative radiation dose is required to estimate the health risk of DU materials. The influences of the solubility parameters in the human alimentary tract and the respiratory tract systems and the aerosol particles size on the radiation dose of DU materials were evaluated.

Influence of human biokinetics of strontium on internal ingestion dose of 90Sr and absorbed dose of 89Sr to organs and metastases.

The objective of the present work is to apply the plasma clearance parameters to strontium, previously determined in our laboratory, to improve the biokinetic and dosimetric models of strontium-90 ((90)Sr) used in radiological protection; and also to apply this data for the estimation of the radiation doses from strontium-89 ((89)Sr) after administration to patients for the treatment of the painful bone metastases. Plasma clearance and urinary excretion of stable strontium tracers of strontium-84 ((84)Sr) and strontium-86 ((86)Sr) were measured in GSF-National Research Center for Environment and Health (GSF) in 13 healthy German adult subjects after intravenous injection and oral administration. The biological half-life of strontium in plasma was evaluated from 49 plasma concentration data sets following intravenous injections.

Internal dose assessment of 210Po using biokinetic modeling and urinary excretion measurement.

The mysterious death of Mr. Alexander Litvinenko who was most possibly poisoned by Polonium-210 ((210)Po) in November 2006 in London attracted the attention of the public to the kinetics, dosimetry and the risk of this high radiotoxic isotope in the human body. In the present paper, the urinary excretion of seven persons who were possibly exposed to traces of (210)Po was monitored.

Modelling urinary excretion of molybdenum after oral and intravenous administration of stable tracers.

An extensive study using stable isotopes of molybdenum as tracers was undertaken to investigate intestinal uptake, systemic kinetics and urinary excretion of molybdenum in healthy human volunteers. In total 63 experiments with 17 volunteers were performed administering the tracers in different chemical forms and measuring their concentrations in blood plasma and urine samples by means of activation analysis and mass spectrometry. Molybdenum was eliminated very rapidly from the circulation.

Plasma clearance and urinary excretion after intravenous injection of stable 84Sr in humans.

Systemic kinetics and urinary excretion after intravenous injection of stable strontium 84Sr were evaluated in 42 investigations in human subjects. Tracer concentrations in plasma and urine were determined by thermal ionisation mass spectrometry. The initial strontium plasma clearance measured after tracer administration was found to be much faster than that predicted by the current model of the International Commission of Radiological Protection (ICRP).

Human biokinetics of strontium--part II: Final data evaluation of intestinal absorption and urinary excretion of strontium in human subjects after stable tracer administration.

Fractional intestinal absorption (f1 value) and urinary excretion of strontium in healthy human volunteers has been measured by simultaneous oral and intravenous administration of the stable isotopes 86Sr and 84Sr using the double-isotope method. Final evaluation of the complete data set confirmed that ingestion of different foodstuff and nutritional factors could influence the fractional gut uptake of strontium. In some cases, significant deviations from the f1 value adopted by the International Commission on Radiological Protection (ICRP) were found.

Human biokinetics of strontium. Part I: intestinal absorption rate and its impact on the dose coefficient of 90Sr after ingestion.

Intestinal absorption of strontium (Sr) in thirteen healthy adult German volunteers has been investigated by simultaneous oral and intravenous administration of two stable tracer isotopes, i.e. (84)Sr and (86)Sr.

Internal dose assessment of natural uranium from drinking water based on biokinetic modeling and individual bioassay monitoring: a study of a Finnish family.

Since the later 1960's, a nationwide survey on natural radionuclides in drinking water showed high concentrations of natural uranium (U) in Finland, especially in uraniferous granite areas. In order to assess the radiation dose from the natural uranium to individuals, the concentrations of natural uranium in drinking water of the drilled wells were determined by radiochemical and alpha spectrometric methods. Uranium contents were measured in the urinary samples of five members of a Finnish family by means of inductively coupled plasma-mass spectrometry.

Biokinetic modeling of uranium in man after injection and ingestion.

Uranium is a naturally occurring primordial radioactive element. Small amounts found in air, water, and food are regularly consumed and inhaled by humans. Even the military, medical, and industrial use of depleted uranium can affect humans.

Juvenile hormone biosynthesis in the fall armyworm, Spodoptera frugiperda (Lepidoptera, Noctuidae).

The in vitro production of juvenile hormones (JH) was investigated by using corpora allata (CA) of larvae and corpora cardiaca-corpora allata (CC-CA) complexes of adult females of the fall armyworm Spodoptera frugiperda. In female moths, JH release was high compared to that in 5th and 6th instar larvae. Concentrations of 0.