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PubMed1998

Molecular genetic characterization of the Philadelphia chromosome detected in reactor personnel highly exposed to radiation from the Chernobyl accident.

Clonal del(22q) chromosome aberrations were coincidentally observed in highly exposed reactor personnel of the Chernobyl power plant accident in the course of retrospective biological dosimetry. These aberrant chromosomes were detected in PHA-stimulated cultures from peripheral blood after FPG staining and revealed a morphology similar to a Philadelphia chromosome. A rearrangement of the BCR gene on 22q11 could be confirmed in unstimulated peripheral blood by RFLP analysis from three of four del(22q) carrying cases. FISH analysis of the del(22q) carrying cases with BCR- and ABL-specific DNA probes additionally exhibited a BCR-ABL fusion in 5.2 to 9% of cells in unstimulated blood. Breakpoints within the BCR gene could be located either in the M-bcr or the m-bcr region and thus, a specific breakpoint region could not be detected in these four patients. Since typical clinical leukemic symptoms associated with the translocation (9;22)(q24;q11) could not be observed in these highly irradiated subjects (1.1 to 5.8 Gy), the role of this particular aberration in the development of a radiation-induced leukemia remains obscure.

Chromosome Deletion↗
PubMed2003

[Association of renal carcinoma and the exposure to ionizing radiation after the Chernobyl accident].

After the nuclear accident of Chernobyl, in the population of zones contaminated the malignant renal tumors was increased from 4.7 to 7.5 per 100,000 of total population. Cesium 137 (137Cs) constitutes 80-90% of the internal exposure of these people as well as eliminated through kidneys becomes an important risk factor. We present a case of a patient, residing in radiocontamined area, who consulted for abdominal pain and left flank mass. We review relevant literature and the management of these patients.

Accidents↗
PubMed2001

Remediation strategies for rural territories contaminated by the Chernobyl accident.

The objective of the present paper is to derive remediation strategies for rural settlements contaminated by the Chernobyl accident in which annual doses to a critical group still exceed 1 mSv. Extensive radioecological data have been collected for 70 contaminated settlements. A dose model based on these data resulted in estimates that are on average close to and a bit less than the official dose estimates ('catalogue doses') published by the responsible Ministries of Belarus, Russia and Ukraine. For eight remedial actions that can be applied on a large scale, effectiveness and costs have been assessed in light of their dependence on soil type, contamination level and on the degree of previous application of remedial actions. Remediation strategies were derived for each of the 70 settlements by choosing remedial actions with lowest costs per averted dose and with highest degree of acceptability among the farmers and local authorities until annual doses are assessed to fall below 1 mSv. The results were generalised to 11 contamination/internal-dose categories. The total numbers of rural inhabitants and privately owned cows in the three countries distributed over the categories were determined and predicted until the year 2015. Based on these data, costs and averted doses were derived for the whole affected population. The main results are (i) about 2000 Sv can be averted at relatively low costs, (ii) the emphasis on reducing external exposures should be increased, (iii) radical improvement of hay-land and meadows and application of Prussian blue to cows should be performed on a large scale if annual doses of 1 mSv are an aim to be achieved, (iv) additional remedial actions of importance are fertilising of potato fields, distribution of food monitors and restriction of mushroom consumption, and (v) for inhabitants of some settlements (in total about 8600) annual doses cannot be reduced below 1 mSv by the remedial actions considered.

Algorithms↗
PubMed2001

Important factors governing exposure of the population and countermeasure application in rural settlements of the Russian Federation in the long-term after the Chernobyl accident.

Rural settlements located in areas of the Russian Federation contaminated after the Chernobyl accident and exceeding an annual dose of 1 mSv a-1 have been classified according to 137Cs contamination density, internal dose and the neighbourhood of forests. It has been shown that, with the exception of the most contaminated areas, the internal doses decreased in accordance with a decline in 137Cs availability for plant root uptake. An inverse tendency was observed in areas with 137Cs contamination above 555 kBq m-2 which can be explained by a reduction or even termination of countermeasure application and by an increasing consumption of forest products in areas where restrictive countermeasures are still implemented. Twenty-seven settlements have been studied to estimate the effectiveness of countermeasures applied previously and to identify the most important factors governing the radiation exposure to the population and its change with time. It has been shown that the effectiveness of countermeasures which resulted in a decrease of up to 40% of doses has a tendency to decline in the long term. The need for continuation of remediation in rural settlements was evaluated both for selected settlements and extrapolated to the whole contaminated area and it has been shown that the application of countermeasures will be of importance at least up to the year 2045. Rather high effectiveness in terms of internal dose reduction (factor of 2-2.5) of radical improvement (disking, ploughing and reseeding) and administration of Cs binders to animals (Ferrocyn) was demonstrated for the selected settlements. It could be demonstrated that for forest-remote settlements there is a linear dependence between internal dose normalised to the density of contamination and the proportion of peat soils around settlements. For near-forest settlements, this dependence was less pronounced which can be explained by the high contribution of forest food products to the internal dose. Milk is still the major dose-forming product in rural Russian settlements (its contribution to internal dose in forest-remote settlements is above 70%); however, in near-forest settlements, the contribution of mushrooms to the internal dose is comparable to the contribution from milk.

Agriculture↗
PubMed2002

A comparison of 90Sr and 137Cs uptake in plants via three pathways at two Chernobyl-contaminated sites.

Foliar absorption of resuspended 90Sr, root uptake and contamination adhering to leaf surfaces (i.e. soil loading) were compared at two Chernobyl-contaminated sites, Chistogalovka and Polesskoye. Although foliar absorption of resuspended 90Sr was quantifiable, its contribution amounted to less than 10% of the plants' total, above-ground contamination. Root uptake was 200 times greater than foliar absorption at the near-field site of Chistogalovka and eight times greater at Polesskoye, where the fallout consisted of the more soluble condensation-type, rather than fuel particles. Strontium's bioavailability exceeded that of 137Cs (analyzed in the same plants) by orders of magnitude when compared using concentration ratios. Simplistic, cumulative effective dose calculations for humans ingesting 90Sr- and 137Cs-contaminated plants revealed that the dose at Chistogalovka was greater from 90Sr (185 mSv vs. 3 mSv from 137Cs), while at Polesskoye the dose from 137Cs (66 mSv) was 30 times greater than from 90Sr (2 mSv).

Absorption↗
PubMed2002

The association of 137Cs with various components of tea leaves fermented from Chernobyl contaminated green tea.

The distribution of 137Cs among various components of fermented tea leaves harvested after the Chernobyl accident was investigated by applying a sequential extraction procedure. An association of the radioisotope with the phenolic moiety of a phenylglucoside was detected in black tea infusate using permeation chromatography as well as UV and NMR spectroscopy. The chemical structure of a 137Cs containing compound also isolated from an artificially 137Cs labelled aqueous extract of green leaves was compared to that of fermented tea leaves. The implications of the findings on the chemical forms of the radionuclide are discussed.

Cesium Radioisotopes↗
PubMed2003

137Cs distribution among annual rings of different tree species contaminated after the Chernobyl accident.

The distributions of 137Cs among annual rings of Pinus sylvestris and Betula pendula at four experimental sites located in the most contaminated areas in the Russian territory after the Chernobyl accident in 1986 were studied. Trees of different ages were sampled from four forest sites with different tree compositions and soil properties. The data analysis shows that 137Cs is very mobile in wood and the 1986 rings do not show the highest contamination. The difference between pine and birch in the pattern of radial 137Cs distribution can be satisfactorily explained by the difference in radial ray composition. 137Cs radial distribution in the wood can be described as the sum of two exponential functions for both species. The function parameters are height, age and species dependent. The distribution of 137Cs in birch wood reveals much more pronounced dependence on site characteristics and/or the age of trees than pines. The data obtained can be used to assess 137Cs content in wood.

Betula↗
PubMed2003

Radiological effects on populations of Oligochaeta in the Chernobyl contaminated zone.

A detailed investigation of 3 populations of Oligochaete species (Dero obtusa, Nais pseudobtusa and Nais pardalis) has been carried out in a contaminated lake of the close-in Chernobyl zone and in a control lake. Hydrochemical indices and concentrations of heavy metals, chloro-organic compounds and (90)Sr in bottom sediments have been measured. Absorbed doses were calculated on the basis of the results of radiochemical analysis and assessed directly with thermoluminescent dosimeters (TLD). Stimulation of paratomous division (asexual reproduction) was found in one species of worm (D. obtusa), and activation of sexual reproduction in the two other species studied. An increase in the amount of cytogenetic damage in the somatic cells of worms from the contaminated lake was found and an attempt was made to assess the relative contributions of radiation and chemical exposure on the basis of analyses of inter-cellular aberration distributions and the types of chromosome aberrations observed in the cells.

Animals↗
PubMed2003

Genetic consequences of radioactive contamination by the Chernobyl fallout to agricultural crops.

The genetic consequences of radioactive contamination by the fallout to agricultural crops after the accident at the Chernobyl NPP in 1986 have been studied. In the first, acute, period of this accident, when the absorbed dose was primarily due to external beta- and gamma-irradiation, the radiation injury of agricultural crops, according to the basic cytogenetic tests, resembled the effect produced by acute gamma-irradiation at comparable doses. The yield of cytogenetic damage in leaf meristem of plants grown in the 10-km zone of the ChNPP in 1987-1989 (the period of chronic, lower level radiation exposure) was shown to be enhanced and dependent on the level of radioactive contamination. The rate of decline with time in cytogenetic damage induced by chronic exposure lagged considerably behind that of the radiation exposure. Analysis of genetic variability in three sequential generations of rye and wheat revealed increased cytogenetic damage in plants exposed to chronic irradiation during the 2nd and 3rd years.

Avena↗
PubMed2003

Long-term flux of Chernobyl-derived 137Cs from soil to French rivers: a study on sediment and biological indicators.

Sediment and aquatic plants were collected annually since the early 1990s in the main French rivers, upstream of nuclear power plants. These time series were used in order to assess the parameters of a compartmental model describing the Chernobyl-derived (137)Cs flux from soil to rivers. In order to reduce the dispersal of (137)Cs measured activities in sediment samples due to the granulometric heterogeneity, a correction method was set up using sediment test-fractions artificially enriched with specific diameter particles. The method was based on (137)Cs affinity for fine particles, especially clays, and thus clay and fine silt contents of each sample was analysed. Corrected sediment data showed (1) that the method efficiently reduced the variability; and (2) that (137)Cs activities in French rivers decreased with a half-life of 4 to 6 years since 1987 (after correction by radioactive decay). A similar half-life value was obtained for aquatic plants pointing out that this half-life is related to the gradual decay of the flux from soil to rivers, not to the indicator itself. Comparing our results with similar ones published by other authors, it appeared possible that this kinetic varies with the time period over which the study is conducted, the longer the period the lower is the kinetic.

Bryopsida↗
PubMed1997

Sonographic determination of cutaneous and subcutaneous fibrosis after accidental exposure to ionising radiation in the course of the Chernobyl nuclear power plant accident.

Chronic cutaneous lesions in eight of 15 survivors of the Chernobyl nuclear energy plant accident presenting with clinical features of cutaneous radiation fibrosis were examined 6 years after exposure using high-frequency ultrasound. In all patients, lesional skin was examined using both the B- and A-modes. Similar phenomena were found in all patients. The corium was increased in thickness as well as density compared to normal skin. The increase in density was seen not only in the medium strata but also particularly at the border between corium and subcutaneous tissue. Within the subcutaneous tissue proper, isles of echo-rich spots were prominent. The number and width of echo signals in the subcutaneous tissue were increased, representing the sonographic correlate of subcutaneous fibrotic trabeculae. The thickness of epidermis plus corium was increased by more than 50% and was even doubled in some cases. According to the present findings obtained from patients with very severe exposure to ionising radiation, ultrasound analysis of cutaneous and subcutaneous radiation fibrosis shows a characteristic picture. Moreover, it was demonstrated that quantitative assessment of skin thickness is possible. As the method is simple and noninvasive, repeated examinations are possible. This provides the basis for monitoring possible treatment effects and efficient follow-up in these chronically progressive clinical conditions after exposure to ionising radiation.

Adult↗
PubMed1999

Interferon gamma in survivors of the Chernobyl power plant accident: new therapeutic option for radiation-induced fibrosis.

BACKGROUND: One of the remarkable clinical consequences of the Chernobyl accident was skin involvement, leading to extensive cutaneous fibrosis. Apart from surgery, no established treatment is available. METHODS: A group of survivors, working in or present at the accident site on April 26, 1986, and a few days thereafter, were examined, treated, and followed-up in 6-month intervals from September 1991 to November 1995. Eight individuals were identified as suffering from excessive cutaneous fibrosis. Skin thickness was measured with high-frequency (20 MHz) ultrasound in a clinically well-defined target skin lesion, in addition to histologic confirmation of radiation fibrosis. Interferon gamma was scheduled for all patients on a low-dose regimen (3 x 50 microg/week s.c.). In 2 patients, interferon was discontinued after the first injection, due to withdrawal of consent. In 6 patients, interferon was continued for 30 months, with 1 injection weekly for a further 6 months. Treatment was discontinued in November 1994. Four patients in the treated group and 1 of the 2 patients treated only once ("untreated patients") were reexamined 1 year later. RESULTS: In all individuals treated for 36 months, a significant (p < 0.005) reduction of radiation fibrosis could be determined, in contrast to a significant (p < 0.005) increase in the 2 untreated patients. Follow-up 1 year after discontinuation of the interferon treatment demonstrated significant (p < 0.005) recurrence of fibrosis. CONCLUSION: Low-dose interferon appears to be a safe and effective treatment of cutaneous radiation fibrosis following accidental exposure to high doses of ionizing radiation. Long-term supportive therapy may be required.

Adult↗
PubMed2000

Stable and unstable aberrations in lymphocytes of Chernobyl accident clearance workers carrying rogue cells.

Cells with multiple chromosomal aberrations, the so-called rogue cells, were found in blood samples from more than 100 Chernobyl accident clearance workers. A comparative analysis of frequencies of stable and unstable chromosomal aberrations in two worker groups--those with or without rogue cells was made. A higher level of unstable aberrations in persons carrying rogue cells was observed. No difference in the level of stable aberrations between the groups was seen. The possibility of low dose alpha irradiation causing the chromosomal damage is raised.

Adult↗
PubMed2000

Cytogenetic features of leukaemias diagnosed in residents of areas contaminated after the Chernobyl nuclear accident.

A comparison of chromosomal abnormalities in bone marrow leukaemic cells and of stable and unstable aberrations in lymphocytes of patients with hematological malignancies who live in areas with or without contamination by the Chernobyl nuclear accident has been made using FISH and G-banding. Healthy residents of these areas comprised the control group. No systematic cytogenetic differences of leukaemic cells between patients from contaminated and uncontaminated areas were observed. Lymphocyte aberrations, however, were generally higher in all subjects from contaminated areas. Comparison has been made with specific cytogenetic features of leukaemic cells and a high level of stable aberrations in lymphocytes of patients with secondary leukaemias that had developed after chemo- and/or radio-therapy.

Adolescent↗
PubMed2000

Separation of Tc-99 in soil and plant samples collected around the chernobyl reactor using a Tc-selective chromatographic resin and determination of the nuclide by ICP-MS

Technetium (Tc) is known to have high mobility in a soil-water system and also high bioavailability for plants, because the most stable form of Tc in natural surface environment is thought to be TcO4- which is highly soluble. The chemical form of Tc, however, changes with environmental conditions. Thus, it is necessary, for realistic assessment, to obtain transfer parameters, such as transfer factors, under natural conditions. However, it is difficult to obtain these parameters using global fallout 99Tc in actual fields due to its low concentration. In this study, 99Tc concentrations in surface soil and plant leaf samples collected from forest sites within the 30-km zone around the Chernobyl reactor were measured for the first time. In the case of soil samples, a simple and rapid analytical method for determination of 99Tc is used which consists of volatilizing and trapping Tc in a combustion apparatus, purifying the Tc with an extraction chromatographic resin, and measuring it by inductively coupled plasma mass spectrometry (ICP-MS). For plant samples, a wet digestion method in combination with the resin is applied and the 99Tc is measured by ICP-MS. Concentrations of 99Tc in organic soil samples and leaves of strawberry (Fragaria vesca) range from 1.1-14.8 Bq kg(-1) dry weight and 0.2-6.0 Bq kg(-1) dry weight, respectively. Our results indicate that soil-to-plant transfer factors for Tc are similar to those for Cs.

Journal Article↗
PubMed2001

The Chernobyl accident: EPR dosimetry on dental enamel of children.

The radiation dose on tooth enamel of children living close to Chernobyl has been evaluated by EPR. The sample preparation was reduced to a minimum of mechanical steps to remove a piece of enamel. A standard X-ray tube at low energy was used for additive irradiation. The filtration effect of facial soft tissue was taken into account. The radiation dose for a group of teeth slightly exceeds the annual dose, whereas for another group the dose very much exceeds the annual dose. Since the higher dose is found in teeth whose enamel have much lower EPR sensitivity to the radiation, it can be suggested that for these teeth the native signal could alter the evaluation of the smaller radiation signal.

Child↗
PubMed2001

Persistence of dicentrics in Chernobyl clean-up workers who suffered from low doses of radiation.

Blood samples from 243 clean-up workers who undertook duties at Chernobyl in 1986 were examined in order to study temporal changes of chromosomal aberrations over long periods (6-12 yr) following irradiation. From an analysis of the elapsed time between irradiation and cytogenetic examination, it was found that the frequency of dicentrics and rings did not decrease during the 6 yr period of observation.

Chromosome Aberrations↗
PubMedDate not supplied

129I and 36Cl concentrations in lichens collected in 1990 from three regions around Chernobyl.

129I and 36Cl were measured by accelerator mass spectrometry in 11 lichen samples (Parmelia sulcata) collected in 1990 from three regions (Novozybkov, Bragin and Ovruc) near Chernobyl. Previously measured activities of 137Cs were highest in the samples from the Novozybkov region while the measured activities of 36Cl and 129I in this study were highest in the samples from the Bragin region. The regional distribution patterns of the 36Cl and 129I show a positive correlation suggesting that these volatile radionuclides were deposited in the same manner.

Chlorine↗