Qualitative assessment of sources and general dependencies in the behavior of anthropogenic radionuclides in the Techa River.

Research on radioactive contamination of the environment involves the important task of assessing the contribution from different sources of contamination. If there are two or more sources of contamination with similar radionuclide composition, assessment of the contribution from each source can be challenging. Such a problem exists, for instance, in the assessment of anthropogenic sources of radioactive contamination of water in the Techa River.

Adaptive response of blood lymphocytes as a marker of hemopoiesis status in exposed persons.

After the onset of a long-term low dose rate radiation exposure (55-60 y later) of the Techa riverside residents within a range of individual red bone marrow (RBM) doses from 0.01 to 1.79 Gy, it was established that there was an obvious association between the type of reaction manifested by peripheral blood lymphocytes to small dose irradiation in vitro (adaptive potential) and the RBM cell composition (during the period of the major exposure), as well as the peripheral blood cell composition (at a late time period coincident with the studies of induced radioresistance).

Characteristics of phytoplankton in Lake Karachay, a storage reservoir of medium-level radioactive waste.

The status of the phytoplankton community in Lake Karachay, a storage reservoir of liquid medium-level radioactive waste from the Mayak Production Association, Chelyabinsk Region, Russia, is reviewed. In 2010, the concentration of Sr in water of this reservoir was found to be 6.5 × 10(6) Bq L, the concentration of 137Cs was 1.

Main dependencies in reduction of radiation exposure to the population of the Southern Urals.

Dynamics of soil contamination, food chain, and radiation doses to population at the East-Urals Radioactive Trace (EURT) and the Karachay Radioactive Trace (KRT) are reviewed. Gamma spectrometric analysis of samples was performed according to standard methodology; 90Sr was determined by the extraction method. Over 80% of radionuclides in soil are contained in the upper 20-cm layer.

Reevaluation of waterborne releases of radioactive materials from the Mayak Production Association into the Techa River in 1949-1951.

The Mayak Production Association was the first site for the production of weapons-grade plutonium in Russia. Early operations led to the waterborne release of radioactive materials into the small Techa River. Residents living downstream used river water for drinking and other purposes.

Preliminary FISH-based assessment of external dose for residents exposed on the Techa River.

This paper presents the results of a feasibility cytogenetic study using the fluorescence in situ hybridization (FISH) translocation assay for residents of villages located on the Techa River (Southern Urals, Russia) contaminated with liquid radioactive wastes from the Mayak plutonium facility in 1949-1956. The study was conducted with two groups of donors that differed in their main pathways of exposure. The first group comprised 18 residents of the middle Techa region who were exposed predominantly from ingestion of radionuclides (mostly (89,90)Sr) via the river water and local foodstuffs.

Cortical bone resorption rate in elderly persons: estimates from long-term in vivo measurements of (90)Sr in the skeleton.

The rate of cortical bone resorption was assessed from long-term in vivo measurements of (90)Sr content in the skeleton for men aged 50-80 years and for women 0-30 years after menopause. Measurements of (90)Sr were conducted with a whole body counter (WBC) for residents of the Techa Riverside communities (Southern Urals, Russia), who ingested large amounts of (90)Sr as a result of releases of liquid radioactive wastes into the river from the Mayak plutonium facility in early 1950s. The results of this study showed an increase in the rate of cortical bone resorption in both men and women, as based on the use of accidentally ingested (90)Sr as a tracer for bone metabolism.

Reconstruction of long-lived radionuclide intakes for Techa riverside residents: strontium-90.

Releases of radioactive materials from the Mayak Production Association in 1949-1956 resulted in contamination of the Techa River; a nuclide of major interest was 90Sr, which downstream residents consumed with water from the river and with milk contaminated by cows' consumption of river water and contaminated pasture. Over the years, several reconstructions of dose have been performed for the approximately 30,000 persons who make up the Extended Techa River Cohort. The purpose of the study described here was to derive a revised reference-90Sr-intake function for the members of this cohort.

Does the cortical bone resorption rate change due to 90Sr-radiation exposure? Analysis of data from Techa Riverside residents.

The Mayak Production Association released large amounts of (90)Sr into the Techa River (Southern Urals, Russia) with peak amounts in 1950-1951. Techa Riverside residents ingested an average of about 3,000 kBq of (90)Sr. The (90)Sr-body burden of approximately 15,000 individuals has been measured in the Urals Research Center for Radiation Medicine in 1974-1997 with use of a special whole-body counter (WBC).

Long-term cellular effects in humans chronically exposed to ionizing radiation.

The aim of the study was to investigate hematopoietic injury and recovery in residents of the Techa riverside villages who had been chronically exposed to radiation as a result of the activities of the Mayak Nuclear Facility, and evaluate late effects from chronic, low-dose radiation exposures. Whole blood samples were drawn from 338 unexposed individuals resident in noncontaminated villages, and 692 individuals chronically exposed externally (to primarily gamma radiation) and internally from Sr since 1949 at decreasing dose-rates which have currently reached the background levels. The mean cumulative dose in the exposed cohort was 0.

Early hematopoietic effects of chronic radiation exposure in humans.

The major goal of this study is to investigate and quantitatively describe the nature of the relationship between the characteristics of chronic exposure to ionizing radiation and specific patterns of hematopoiesis reduction. The study is based on about 3,200 hemograms taken for inhabitants of the Techa riverside villages over the years 1951-1956, i.e.

Late effects in hemopoiesis and bone tissue among people with incorporated osteotropic isotope 90Sr.

Unlabelled: The present paper focuses on the analysis of data resulting from 50-y studies involving assessment of the hemopoiesis state in Techa riverside residents chronically exposed to radiation and evaluation of the bone tissue status for people with Sr incorporation at late time after the intakes.

Conclusions: 1. In the late period after the start of chronic radiation exposure (50 y later) only a few individuals with red bone marrow doses reaching about 1.

Early hematopoiesis inhibition under chronic radiation exposure in humans.

The major goal of this study was to identify and quantitatively describe the association between the characteristics of chronic (low-dose rate) exposure to (low LET) ionizing radiation and cellularity of peripheral blood cell lines. About 3,200 hemograms (i.e.

Leukemia incidence among people exposed to chronic radiation from the contaminated Techa River, 1953-2005.

Beginning in 1950, people living on the banks of the Techa River received chronic low-dose-rate internal and external radiation exposures as a result of releases from the Mayak nuclear weapons plutonium production facility in the Southern Urals region of the Russian Federation. The Techa River cohort includes about 30,000 people who resided in riverside villages sometime between 1950 and 1960. Cumulative red bone marrow doses range up to 2 Gy with a mean of 0.

Evaluation of anthropogenic dose distribution amongst building walls at the Metlino area of the upper Techa River region.

This paper presents the results of an effort to evaluate anthropogenic doses in bricks from old buildings located on the banks of the Techa River. The river area was contaminated in 1949-1956 as a result of radioactive waste releases by the Mayak plutonium facility (Southern Urals, Russia). Absorbed doses were determined by luminescence measurements of quartz extracted from the near-surface layers of bricks sampled in 1991-1997 from three remained buildings (a mill, a granary and a church).

Reconstruction of (90)Sr intake for breast-fed infants in the Techa riverside settlements.

The Techa River (Southern Urals, Russia) was contaminated as a result of radioactive releases by the Mayak plutonium production facility during 1949-1956. The persons born after the onset of the contamination have been identified as the "Techa River Offspring Cohort" (TROC). The TROC has the potential to provide direct data on health effects in progeny that resulted from exposure of a general parent population to chronic radiation.

Solid cancer incidence and low-dose-rate radiation exposures in the Techa River cohort: 1956 2002.

Background: This is the first analysis of solid cancer incidence in the Techa River cohort, a general population of men and women of all ages who received chronic low-dose rate exposures from environmental radiation releases associated with the Soviet nuclear weapons programme. This cohort provides one of the few opportunities to evaluate long-term human health risks from low-dose radiation exposures.

Methods: Cancer incidence rates in this cohort were analysed using excess relative risk (ERR) models.

In utero and postnatal haemopoietic tissue doses resulting from maternal ingestion of strontium isotopes from the Techa River.

Reliable estimates of tissue doses to individuals exposed as a result of radioactive releases to the Techa River are essential prerequisites for epidemiological analyses. This paper describes progress made in collaborative studies, sponsored by the European Union, between the Urals Research Center for Radiation Medicine and the UK Health Protection Agency to provide dose estimates to Techa River populations following in utero exposures and infant exposures resulting from breast-feeding. Studies have concentrated on the assessment of internal doses from 90Sr as the main contributor to internal doses to the Techa River populations.

Possibilities of using human teeth for retrospective dosimetry: analysis of the Techa River data.

Different methods for utilising teeth were applied for the reconstruction of internal and external doses for the population of the Techa riverside area contaminated as a result of radioactive releases from the Mayak plutonium-production facility. Information on 90Sr content in the enamel of teeth obtained from the Techa River residents has been used for the reconstruction of intakes of this nuclide. Analyses of dosimetric investigations on dental tissues performed in the Techa River region provide an understanding of the possibilities and limitations of using human teeth in retrospective dosimetry studies.

Development of an improved dose reconstruction system for the Techa River population affected by the operation of the Mayak Production Association.

The Techa River Dosimetry System (TRDS) has been developed to provide estimates of dose received by approximately 30,000 members of the Extended Techa River Cohort (ETRC). Members of the ETRC were exposed beginning in 1949 to significant levels of external and internal (mainly from (90)Sr) dose but at low to moderate dose rates. Members of this cohort are being studied in an effort to test the hypothesis that exposure at low to moderate dose rates has the same ability to produce stochastic health effects as exposure at high dose rates.

Risk analysis of leukaemia incidence among people living along the Techa River: a nested case-control study.

Large quantities of radioactive materials released over time from the Mayak nuclear weapons facility caused significant internal and external exposure for people living along the banks of the Techa River (Southern Urals, Russia). We conducted a nested case-control study in the Extended Techa River Cohort to determine whether the risk of leukaemia incidence increased with protracted exposure to ionising radiation or with other non-radiation risk factors. The study included 83 cases identified over 47 years of follow-up and 415 controls matched for sex, age at diagnosis, age (within a 5 year age group), and date of initial residence in the riverside area.

Protracted radiation exposure and cancer mortality in the Techa River Cohort.

In the 1950s many thousands of people living in rural villages on the Techa River received protracted internal and external exposures to ionizing radiation from the release of radioactive material from the Mayak plutonium production complex. The Extended Techa River Cohort includes 29,873 people born before 1950 who lived near the river sometime between 1950 and 1960. Vital status and cause of death are known for most cohort members.

The Techa River Cohort: study design and follow-up methods.

Residents living on the banks of the Techa River in the Southern Urals region of Russia were exposed to radioactive contamination from the Mayak plutonium production and separation facility that discharged liquid radioactive waste into this river. This paper describes the methods used to establish and follow the Extended Techa River Cohort (ETRC), which includes almost 30,000 people living along the Techa River who were exposed to a complex mixture of radionuclides, largely 90Sr and 137Cs. The system of regular follow-up allows ascertainment of vital status, cause of death and cancer incidence.

Assessment of 90Sr concentration in dental tissue using thin-layer beta-particle detectors and verification with numerical calculations.

Electron paramagnetic resonance (EPR) measurements of tooth enamel can be used as an individual biological dosimeter for external dose assessment. However, the presence of 90Sr in the tooth tissues makes the task of interpreting EPR tooth dosimetry more complicated. The determination of the dose contribution of incorporated 90Sr in calcified tissue to the total dose measured by EPR is one of the main aspects of correct interpretation of EPR tooth dosimetry.