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PubMed1997

Issues in the comparison of risk estimates for the population in the Techa River region and atomic bomb survivors.

Plutonium production in the former Soviet Union began in 1949 at the Mayak Production Association located between the cities of Chelyabinsk and Ekaterinbourg in the southern Ural mountains about 1200 km east to Moscow. During the first few years of Mayak's operation, almost 30,000 people living on the banks of the Techa River received significant internal and external exposures as a consequence of the release of large quantities of radioactive materials from Mayak. Studies of levels of radioactive contamination and health effects in this population began in the early 1950s. A systematic follow-up of a fixed cohort that includes all people who were living in Techa River villages in 1949 was begun about 30 years ago. In this paper we describe the Techa River cohort, outline the nature of the exposures and discuss the status of follow-up for the period from 1950 through 1989. While noting the limitations of the current epidemiological follow-up data, we also compare the demographic and mortality structure of the Techa River cohort with the Life Span Study cohort of Japanese atomic bomb survivors. It is seen that, despite a number of limitations, the current data suggest that the risks of mortality from leukemia and other cancers increase with increasing radiation dose in the Techa River cohort. This finding suggests that, with continued improvements in the quality of the follow-up and dosimetry, the Techa River cohort has the potential to provide quantitative estimates of the risks of chronic low-dose-rate radiation exposures for an unselected general population that will be an important complement to the estimates based on the Life Span Study that are used as the primary basis for numerical assessments of radiation risk.

Environmental Exposure↗
PubMed1997

[Modeling of cutaneous radio-contamination: effects of washings by soap and by solutions of DTPA].

Some neutral chirurgical soap, a solution of diethylen penta acetic acid (DTPA) at 1% and a solution at 25% of monocalcic trisodium salt of DTPA in serum have been studied on models of cutaneous contamination. Cesium 137 (137Cs) and Plutonium 239 (239Pu) have been used for the contamination. This research gives a protocol for external cutaneous decontamination which could be used in reception units for radiocontaminated wounded. Even the radioelement is unknown, DTPA at 25% represents a good solution for the treatment of general contamination, which is not the case for DTPA at 1%. A soap in which DTPA at 1% has been added is adapted for large cutaneous contamination. The treatment of ocular contamination is also studied in this article.

Burns, Chemical↗
PubMed1997

Topological structure activity analysis of diphosphonates in the elimination of radionuclides from body.

The effectiveness of a series of diphosphonates in the elimination of radionuclides from rat was analyzed by means of topological structure and activity relations. It is possible to compute some numbers or indexes characteristic of the topological structure of a molecule. The Wiener Index which measures the ramification of a molecule has been chosen. An attempt was made to correlate the effectiveness of the molecules tested in removing plutonium from the organism to their Wiener Index. Only unprotected molecules i.e in free acidic form fitted the correlation. LICAM (C) and DTPA were used as reference molecules to control these results. The fact that LICAM (C) well fitted the relation and that DTPA did not are discussed, as are some general requirements for a new molecule to be effective.

Animals↗
PubMed1997

Regression estimator in ranked set sampling.

Ranked set sampling (RSS) utilizes inexpensive auxiliary information about the ranking of the units in a sample to provide a more precise estimator of the population mean of the variable of interest Y, which is either difficult or expensive to measure. However, the ranking may not be perfect in most situations. In this paper, we assume that the ranking is done on the basis of a concomitant variable X. Regression-type RSS estimators of the population mean of Y will be proposed by utilizing this concomitant variable X in both the ranking process of the units and the estimation process when the population mean of X is known. When X has unknown mean, double sampling will be used to obtain an estimate for the population mean of X. It is found that when X and Y jointly follow a bivariate normal distribution, our proposed RSS regression estimator is more efficient than RSS and simple random sampling (SRS) naive estimators unless the correlation between X and Y is low (/rho/ < 0.4). Moreover, it is always superior to the regression estimator under SRS for all rho. When normality does not hold, this approach could still perform reasonably well as long as the shape of the distribution of the concomitant variable X is only slightly departed from symmetry. For heavily skewed distributions, a remedial measure will be suggested. An example of estimating the mean plutonium concentration in surface soil on the Nevada Test Site, Nevada, U.S.A., will be considered.

Biometry↗
PubMed1997

Biological effects of inhaled 238PuO2 in beagles.

Beagle dogs exposed to 238PuO2 aerosols (136 dogs, 13-22 per group, mean initial lung depositions of 0.0, 0.13, 0.68, 3.1, 13, 52 and 210 kBq) were observed throughout life to determine tissues at risk and dose-effect relationships. The pulmonary retention of 238Pu was represented by the sum of two exponentially decreasing components of the initial lung deposition; about 84% cleared with a 174-day half-time; the half-time of the remainder was 908 days. The average percentages of final body burden found in lung, skeleton, liver and thoracic lymph nodes in the 30 longest-surviving dogs (mean survival 14 years) were 1, 46, 42 and 6%, respectively. Of 116 beagles exposed to plutonium, 34 (29%) developed bone tumors, 31 (27%) developed lung tumors, and 8 (7%) developed liver tumors. Although lungs accumulated a higher average radiation dose than skeleton, more deaths were due to bone tumors than to lung tumors. Deterministic effects included radiation pneumonitis, osteodystrophy, hepatic nodular hyperplasia, lymphopenia, neutropenia and sclerosing tracheobronchial lymphadenitis. Hypoadrenocorticism was also observed in a few dogs. Increased serum alanine aminotransferase, indicative of liver damage, was observed in groups with > or =3.1 kBq initial lung deposition. Estimates of cumulative tissue dose in a human exposed to airborne 238PuO2 for 50 years at a rate of one annual limit on intake each year were derived based on a comparison of the data on metabolism for humans and beagles. The 50-year dose estimates for humans are an order of magnitude lower than doses at which increased incidence of neoplasia was observed in these dogs, whereas the projected doses to humans from 50-year exposure at the annual limit of intake are of similar magnitude to those at which deterministic effects were seen in the beagles.

Addison Disease↗
PubMed1997

[Age-related dynamics of the genetic marker distribution in an irradiated population. Haptoglobin genetic system].

The age dynamics of haptoglobin (Hp) type and allele distribution was studied in 985 workers aged 35-79 years who worked in the atomic industry. These workers were exposed to chronic radiation in a wide range of doses 17-40 years ago. Along with the chi 2 test, the relative and attributive risks of elimination of Hp types and alleles were determined to obtain the qualitative characteristics of age alterations. The substantial changes in distribution of Hp types and alleles were revealed in individuals older than 60 years. These changes depended on doses of external and internal irradiation. For instance, in individuals of this age group, who received the total dose of gamma-radiation (less than 100 cGy) and or that of plutonium-239 incorporation (less than 1.48 kBq), a decrease in Hp 2-2 and Hp2 and an increase in Hp 1-1 and Hp1 was observed. However, among the individuals of similar age (older than 62 years), who received a higher total dose of external and/or internal radiation, the different Hp type distribution showed a decrease in Hp 2-1 and an increase in Hp 1-1. In the latter case, the changes with age were dose-dependent. In individuals over 60 years of age with essential hypertension or diabetes mellitus and those who had a myocardial infarction, a decrease in Hp 2-2 and Hp2 and an increase in Hp 1-1 and Hp1 were found. This explains the changes with age in individuals irradiated at lower doses. The peculiar changes with age in individuals irradiated at higher doses are possibly due to the difference in morbidity and mortality from malignancy in various Hp type carriers.

ABO Blood-Group System↗
PubMed1983

Structure, cytochemistry, endocytic activity, and immunoglobulin (Fc) receptors of rat testicular interstitial-tissue macrophages.

Macrophages are common in rat testicular interstitial tissues. Interstitial-tissue macrophages were characterized using ultrastructural, cytochemical, immunologic, and autoradiograhic methods. Testicular interstitial-tissue macrophages have a single indented nucleus, paranuclear Golgi complex, rough endoplasmic reticulum, coated vesicles, and numerous heterogeneous lysosomal vacuoles. Long filopodia and lamellopodia extent from the macrophage cell body into the lymphatic space. Macrophages are usually found adjacent to Leydig cells, and numerous Leydig cell processes are inserted into coated membrane invaginations on the macrophage surface. Secondary lysosomal vacuoles in the macrophage are cytochemically reactive for acid phosphatase (trimetaphosphatase) and aryl sulfatase. Testicular interstitial macrophages are endocytically active, avidly incorporating exogenously administered trypan blue dye and monomeric plutonium-citrate. Macrophages were isolated from the testes by allowing them to adhere to glass. The isolated macrophages were found to have receptors for the Fc portion of immunoglobulin G on their surface. The association of macrophages with Leydig cells and their endocytic and immunologic activity suggests that these cells may play an important role(s) in testicular functions. In addition, the ability of these cells to incorporate exogenous materials indicates that they could have a role in gonadal toxicity reactions.

Animals↗
PubMed1992

Health physics: its development, successes, failures, and eccentricities.

Health Physics began at the University of Chicago as a science and profession during the early World War II years. It was initiated by Drs. A.H. Compton and R.S. Stone, director and associate director, respectively, of the early Plutonium Project cryptically called the Metallurgical Laboratory. It was to be a science and a profession to protect radiation workers and members of the public from exposure to ionizing radiation. It succeeded to some extent in this objective but during the past decade in the United States, it has reverted into an organization primarily to protect the nuclear industry from liability resulting from radiation exposure.

Health Physics↗
PubMed1984

Identification and characterization of mononuclear phagocytes isolated from rat testicular interstitial tissues.

Rat testicular interstitial tissues contain numerous mononuclear phagocyte-like cells. Dispersed testicular tissues are allowed to settle onto a glass substrate and the strongly adherent cells are identified as the same cells that have been described in vivo, based on the retention of an in vivo marker (plutonium). These putative testicular intersitial tissue macrophages (TIMs) have adhesion and cell surface features characteristic of mononuclear phagocytes, as determined by scanning electron microscopy. Immediately after isolation from testicular tissues, TIMs show a strong staining reaction for nonspecific esterase. These cells have Fc and complement receptors and some express Ia cell-surface antigens. About two thirds of the TIMs phagocytose sheep red blood cells and most of the cells are capable of nonspecific phagocytosis of polystyrene beads. This study demonstrates that the phagocytic cells found in testicular interstitial tissues have morphological, histochemical, phagocytic, and immunological properties characteristic of functionally active mononuclear phagocytes. These results suggest that these resident mononuclear phagocytes may play a role in immune-related functions in the testis.

Animals↗
PubMed1996

Radioepidemiology in the aftermath of the nuclear program of the former Soviet Union: unique lessons to be learnt.

The military and civilian nuclear activities in the former Soviet Union led to unique exposures and resulted in high cumulative doses in several populations. In comparison to the atomic bomb survivors, at present the most important cohort in radiation epidemiology, collective and individual doses received by early workers in the plutonium production facilities at Mayak (Chelyabinsk). Techa River residents downstream of Mayak, populations downwind of the Semipalatinsk test site, and subpopulations of Chernobyl victims surpass the Hiroshima/Nagasaki experience in most cases. Even more importantly, the dose rates cover the full range of exposures relevant for radiation protection. i.e., acute to year-long chronic exposures from environmental contamination and bone seeking radionuclides. Parallel to the humanitarian need to mitigate health effects from these exposures, the unique opportunities for research on radiation risks related to low dose rate and chronic radiation have to be explored. Increased efforts by the global radiation research community are needed to address the many questions which cannot be answered by the acutely irradiated survivors of Hiroshima/Nagasaki. Specific attention needs to be drawn to the validation of available exposure and health records and to dose reconstruction which must include dietary sources of exposure. Preliminary intercomparison and validation exercises indicate potentially large sources of error, e.g., due to uncertainties in the reconstruction of early exposures and effects and due to continuing incorporation.

Dose-Response Relationship, Radiation↗
PubMed2001

Determination of uranium isotopic composition and 236U content of soil samples and hot particles using inductively coupled plasma mass spectrometry.

As a result of the accident at the Chernobyl nuclear power plant (NPP) the environment was contaminated with spent nuclear fuel. The 236U isotope was used in this study to monitor the spent uranium from nuclear fallout in soil samples collected in the vicinity of the Chernobyl NPP. Nuclear track radiography was applied for the identification and extraction of hot radioactive particles from soil samples. A rapid and sensitive analytical procedure was developed for uranium isotopic ratio measurement in environmental samples based on double-focusing inductively coupled plasma mass spectrometry (DF-ICP-MS) with a MicroMist nebulizer and a direct injection high-efficiency nebulizer (DIHEN). The performance of the DF-ICP-MS with a quartz DIHEN and plasma shielded torch was studied. Overall detection efficiencies of 4 x 10(-4) and 10(-3) counts per atom were achieved for 238U in DF-ICP-QMS with the MicroMist nebulizer and DIHEN, respectively. The rate of formation of uranium hydride ions UH+/U+ was 1.2 x 10(-4) and 1.4 x 10(-4), respectively. The precision of short-term measurements of uranium isotopic ratios (n = 5) in 1 microg L(-1) NBS U-020 standard solution was 0.11% (238U/235U) and 1.4% (236U/238U) using a MicroMist nebulizer and 0.25% (235U/238U) and 1.9% (236U/P38U) using a DIHEN. The isotopic composition of all investigated Chernobyl soil samples differed from those of natural uranium; i.e. in these samples the 236U/238U ratio ranged from 10(-5) to 10(-3). Results obtained with ICP-MS, alpha- and gamma-spectrometry showed differences in the migration properties of spent uranium, plutonium, and americium. The isotopic ratio of uranium was also measured in hot particles extracted from soil samples.

Mass Spectrometry↗
PubMed1996

Detection of trace radioisotopes in soil, sediment and vegetation by glow discharge mass spectrometry.

The possibility for the determination of some radioisotopes of cesium, strontium, plutonium, uranium and thorium by glow discharge mass spectrometry (GDMS) in soils, sediments and vegetations is investigated. The preparation of samples is described as a combination of the use of a conductive host matrix and a secondary cathode in order to decrease the dilution effect of the blending material for the trace level determination and to gain a stable discharge. Effects of interferences arising from the nature of the conductive host matrix and of the secondary cathode on the sensitivity of the method are discussed. The determination of (137)Cs and (90)Sr has been attempted and the results obtained were in agreement with those from other analytical techniques. Accuracy, internal and external precisions have been also evaluated. GDMS is shown to be a helpful technique for the determination of radioisotopes in environmental samples. Radioisotopes can be determined according to the matrix of the sample (e.g. grass), also in presence of isobaric interferences. However, limitations still exist on the application of GDMS.

Journal Article↗
PubMed2006

The potential for chromium to affect the fertilization process of Chinook salmon (Oncorhynchus tshawytscha) in the Hanford reach of the Columbia River, Washington, USA.

The Hanford Nuclear Reservation in south central Washington was claimed by the federal government as a site for the production of plutonium. During the course of production and operation of the facilities at Hanford, radionuclides and chromium were discharged directly into the river and also contaminated the groundwater. This study was designed to assess the effects of chromium (Cr) on Chinook salmon (Oncorhynchus tshawytscha) fertilization under exposure conditions similar to those of the Hanford Reach of the Columbia River. Chinook salmon gametes were exposed to aqueous Cr concentrations ranging from 0 to 266 microg Cr l(-1). The current ambient water-quality criteria (AWQC) established for the protection of aquatic life (United States Environmental Protection Agency [USEPA] 1986) is 11 microg Cr l(-1). Cr has been measured in pore water from bottom sediments of the Columbia River at concentrations >600 microg Cr l(-1). Under exposure conditions designed to closely mimic events that occur in the river, the fertilization of Chinook salmon eggs was not affected by concentrations of Cr ranging from 11 to 266 microg Cr l(-1). Data suggest that the instantaneous nature of fertilization likely limits the potential effects of Cr on fertilization success. As a result, the current AWQC of 11 mug Cr l(-1) is most likely protective of Chinook salmon fertilization.

Animals↗
PubMed2001

Fetal dose assessment for the offspring of the Techa Riverside residents.

Massive releases of fission products from the plutonium facility Mayak (Southern Urals, Russia) resulted in the contamination of the Techa river and its floodlands (1949-1956). The results of long-term studies of exposure populations have been used for different purposes of retrospective dosimetry. The riverside residents were exposed via various pathways and their progeny were exposed in utero both to external radiation and to internal radiation from radionuclides ingested by the mothers prior to conception and during pregnancy. Fetal doses due to 90Sr from the maternal skeleton were estimated and compared with doses from other pathways. Individual red bone marrow (RBM) doses to the late fetuses were calculated on the basis of 90Sr contents measured in the maternal skeleton and the 90Sr transfer coefficients (TC) to the fetal skeleton were determined on the basis of the Techa river data. Two values of TC were assumed depending on the mothers' maturation status in the period of maximum releases: TC=0.2 for group 1 (adulthood of mothers in 1950) and TC=0.02 for group 2 (mothers not yet in menarche age in 1950). Fetal doses in both groups that resulted from the different TC values varied by a factor of about 5-8. Furthermore, the fetal RBM doses due to 90Sr from the maternal skeleton were found to depend on the distances from the site of release and the time after major 90Sr intake. The average fetal RBM doses in the population of the upper, middle and lower Techa riverside regions were close to the ratio 3:2:1 and 20 years after the onset of contamination, the fetal doses have decreased by a factor of about 3-5. The distance from the site of release determined the relative contribution of different pathways to the fetal dose. For the settlements that are located closest to the site of release, the external exposure was of major concern up to the date of evacuation. For the non-evacuated settlements, the contribution of internal doses was higher and after 1956, external exposure is assumed to be negligible. From 1956 on, 90Sr that has been transferred from the maternal skeleton was practically the single source of in utero exposure.

Adult↗
PubMed2004

Radiostrontium contamination of soil and vegetation within the Semipalatinsk test site.

The Semipalatinsk nuclear test site (STS) in the Republic of Kazakhstan was an important site for testing atomic bombs and other civil and military nuclear devices of the former Soviet Union. Results are presented from investigations on the extent of radiostrontium contamination in soils and vegetation at the technical areas of the STS, where the tests were conducted and in pastures used by farmers for grazing animals or for hay production. Our data are compared with those reported largely in the recent Russian language literature that has been reviewed. The extent of (90)Sr contamination of soil is highly variable over the STS with the highest values associated with the technical areas, particularly the Degelen mountains. Recently measured values in both the present data and the Russian language literature confirm the relatively high current contamination of soil and vegetation in the vicinity of tunnels and associated watercourses in the Degelen area. The proportion of (90)Sr in soil which could not be extracted with 6 M HCl was only an average of 20%, which is low compared to other test site areas and possibly indicates a relatively high mobility in this area, because the (90)Sr is derived from leakage from explosion tunnels along watercourses rather than being associated with fused silicates. A comparison of relative activity concentrations in soil and vegetation suggests that the transfer of (90)Sr to vegetation on the STS is high compared to that of (137)Cs and plutonium.

Crops, Agricultural↗
PubMed2006

Comparison of EPR occupational lifetime external dose assessments for Mayak nuclear workers and film badge dose data.

The Mayak worker cohort is one of the major sources of information on health risks due to protracted exposures to plutonium and external ionizing radiation. Electron paramagnetic resonance (EPR) measurements in tooth enamel in combination with personal dose monitoring can help to improve external dose assessment for this cohort. Here, the occupational lifetime external exposure was evaluated individually for 44 nuclear workers of three plants of the Mayak Production Association by EPR measurements of absorbed doses in collected tooth enamel samples. Analysis included consideration of individual background doses in enamel and dose conversion coefficients specific for photon spectra at selected work areas. As a control, background doses were assessed for various age groups by EPR measurements on teeth from non-occupationally exposed Ozyorsk residents. Differences in occupational lifetime doses estimated from the film badges and from enamel for the Mayak workers were found to depend on the type of film badge and the selected plant. For those who worked at the radiochemical processing plant and who were monitored with IFK film badges, the dose was on average 570 mGy larger than estimated from the EPR measurements. However, the average difference was found to be only -4 and 6 mGy for those who were monitored with IFKU film badges and worked at the reactor and the isotope production plant respectively. The discrepancies observed in the dose estimates are attributed to a bias in film badge evaluation.

Adult↗
PubMed2005

Metal concentrations, foraging distances, and fledging success of great blue herons nesting along the Hanford Reach of the Columbia River.

An ecological risk assessment of the spatial distribution of metal concentrations along the Hanford Reach of the free-flowing Columbia River in southcentral Washington, identified great blue herons, Ardea herodias, at potential risk through the ingestion of contaminated riverine biota, especially fish. We measured metal concentrations in livers of pre-flight herons from the Hanford Reach and excrement samples taken from the same nests. Nests were distributed among three colonies situated upstream and downstream from nine retired plutonium production reactors along the river where metals in reactor coolant waters had been released directly into the river or disposed to shoreline retention basins and ditches. Distances traveled by parent herons to foraging areas along the river shore were determined by visually tracking parent birds as they flew from nests to upriver and downriver foraging sites. Foraging flight distances varied between colonies with mean distances ranging between 0.7 and 3.1 km. Cadmium, Cr, and Pb concentrations were higher in excrement than in the livers of pre-flight herons but the opposite was noted for Cu, Hg, and Zn. Highest metal concentrations of Cr, Cu, Zn, Cd, and Pb, were measured in excrement taken from heron nests at the colony located upstream from all reactors. These results were consistent with metal concentrations reported in river sediment from the same regions, indicating excrement from the heron nests may be a useful indicator of dietary uptake of metals by herons. Fledging success and eggshell thickness measurements were used as an index of health of the local heron population. The results indicate that the reproductive health of great blue herons nesting along the Hanford Reach is among the highest reported in the continental United States.

Animals↗
PubMed2007

Metals and radionuclides in birds and eggs from Amchitka and Kiska Islands in the Bering Sea/Pacific Ocean ecosystem.

Metals and radionuclide levels in marine birds of the Aleutians are of interest because they are part of subsistence diets of the Aleut people, and can also serve as indicators of marine pollution. We examined geographic and species-specific variations in concentrations of radionuclides in birds and their eggs from Amchitka, the site of underground nuclear tests from 1965 to 1971, and Kiska Islands (a reference site) in the Aleutians, and the levels of lead, mercury and cadmium in eggs. In 2004 we collected common eiders (Somateria mollissima), tufted puffins (Fratercula cirrhata), pigeon guillemot (Cepphus columba) and glaucous-winged gulls (Larus glaucescens) from Amchitka and Kiska, and eggs from eiders and gulls from the two island. We also collected one runt bald eagle (Haliaeetus leucocephalus) chick from both Amchitka and Kiska Islands. For most species, the levels of radionuclide isotopes were below the minimum detectable activity levels (MDA). Out of 74 cesium-137 analyses, only one composite (gulls) was above the MDA, and out of 14 composites tested for plutonium (Pu-239, 240), only one exceeded the MDA (a guillemots). Three composites out of 14 tested had detectable uranium-238. In all cases, the levels were low and close to the MDAs, and were below those reported for other seabirds. There were significant interspecific differences in metal levels in eggs: gulls had significantly higher levels of cadmium and mercury than the eiders, and eiders had higher levels of lead than gulls. There were few significant differences as a function of island, but eiders had significantly higher levels of cadmium in eggs from Kiska, and gulls had significantly higher levels of mercury on Kiska. The levels of cadmium and mercury in eggs of eiders and gulls from this study were above the median for cadmium and mercury from studies in the literature. The levels of mercury in eggs are within the range known to affect avian predators, but seabirds seem less vulnerable to mercury than other birds. However, the levels of mercury are within the action levels for humans, suggesting some cause for concern if subsistence Aleuts eat a large quantity of eggs.

Alaska↗