Title: Transport of radioactive particles from the chernobyl accident
Author: Roy Pöllänen, Ilkka Valkama, Harri Toivonen
Reference: Atmospheric Environment, Volume 31, Issue 21, November 1997, Pages 3575-3590
DOI: http://dx.doi.org/10.1016/S1352-2310(97)00156-8
Keywords: Chernobyl accident; radioactive particles; long-range transport; particle transport
Abstract: After the Chernobyl accident large and highly radioactive particles were found in several European countries. Particles > 20 μm in aerodynamic diameter were transported hundreds of kilometres from the plant, and they were sufficiently active (> 100 kBq) to cause acute health hazards. Here, a particle trajectory model is used to identify the areas of large particle fallout. Effective release height of the particles and atmospheric phenomena related to their transport are investigated by comparing particle findings with locations given by trajectory calculations. The calculations showed that in the Chernobyl accident either the maximum effective release height must have been considerably higher than previously reported (> 2000 m) or convective warm air currents may have lifted radioactive material upwards during transport. Large particles have been transported to other areas than small particles and gaseous species. The particulate nature of the release plume must be taken into account in dispersion and transport analyses. Air parcel trajectories alone are not necessarily sufficient for identifying the fallout area of radioactive material.
URL: http://www.sciencedirect.com/science/article/pii/S1352231097001568
Title: Transfer of radiocaesium in sensitive agricultural environments after the Chernobyl fallout in Sweden: III. County of Västernorrland
Author: K. Rosén, E. Haak, Å. Eriksson
Reference: Science of The Total Environment, Volume 209, Issues 2–3, 19 January 1998, Pages 91-105
DOI: http://dx.doi.org/10.1016/S0048-9697(98)80100-9
Keywords: Radiocaesium; Radioiodine; Chernobyl; Nuclear fallout; Grass; Cereals
Abstract: In 1986 a large number of farms in the Chernobyl-affected area in the county of Västernorrland in northern Sweden were investigated for radiocaesium transfer to grass and cereal grain. The soil surface layer (0–5 cm) in 1986 and the crop products in 1986–1996 were analysed. The aim was to study the impact of soil and crop rotation on sensitivity of 137Cs transfer in a short and long term perspective. In the fallout year 1986 the transfer to grass was usually much higher than to cereal grain. In this year the transfer to grass was usually much higher in the first cut rather than the second cut. The reduction in transfer with year was large but variable with site and with crop sequence. Ploughing was effective in decreasing the transfer of 137Cs to crops. On arable sites in 1986 the transfer to cereal straw was larger at late stem elongation (LSE) than at the maturing stage. Unexpectedly, there was no clear relationship between transfer of 137Cs to the crops and any of the soil characteristics. In 1986 the transfer of 131I to grass and cereals was also investigated on some of the farms. The results are compared with the transfer of 137Cs, 2 months after the Chernobyl fallout.
URL: http://www.sciencedirect.com/science/article/pii/S0048969798801009
Title: Transfer of radiocaesium in sensitive agricultural environments after the Chernobyl fallout in Sweden. II. Marginal and seminatural areas in the county of Jämtland
Author: Klas Rosén
Reference: Science of The Total Environment, Volume 182, Issues 1–3, 5 April 1996, Pages 135-145
DOI: http://dx.doi.org/10.1016/0048-9697(95)05059-0
Keywords: Radiocaesium; Grass; Fallout; Chernobyl; Contamination
Abstract: In 1986, two Chernobyl-affected areas in the county of Jämtland, a mountain area and a river valley area, were investigated as to radiocaesium behaviour and transfer to grass. The soil surface layer (0–10 cm) in 1986 and 1989 and grass samples in 1986–1994 were analysed on 9 temporary grassland sites and 8 permanent pasture sites, described individually. The aim of this investigation was to study the sensitivity of different soil types and the influence of normal farming practices, ploughing and K-fertilization on the caesium transfer, in short- and long-term perspectives after the Chernobyl fallout. As expected, the transfer of 137Cs to grass was usually higher on permanent pasture than on temporary grassland. For both types of grassland, however, there was a considerable but different change of transfer with years. The transfer to grass in the year of the fallout, 1986, depended to a large extent on the thickness and interception capacity of the grass sward. In the following years, it also depended on the caesium-fixing capacity to clay minerals, on K-fertilization and the reverse process of K removal by plant uptake. Ploughing down the contaminated surface layer and the mixing of caesium with mineral soil were effective in reducing the transfer. During the period 1986–1994, the transfer was reduced considerably, showing a range of (0.1–177.3 m2/kg d.w.) × 10−3. The calculated annual reduction halftime, Tar, increased with years after fallout. It is clearly shown that both countermeasures, ploughing and K-fertilization, are of potential value to decrease grass contamination. Where both measures were employed a reduction in the range of 78%–95% was recorded in the year after ploughing.
URL: http://www.sciencedirect.com/science/article/pii/0048969795050590
Title: Transfer of radiocaesium in sensitive agricultural environments after the Chernobyl fallout in Sweden. I. County of Gävleborg
Author: Klas Rosén, Åke Eriksson, Enok Haak
Reference: Science of The Total Environment, Volume 182, Issues 1–3, 5 April 1996, Pages 117-133
DOI: http://dx.doi.org/10.1016/0048-9697(95)05056-6
Keywords: Radiocaesium; Chernobyl; Nuclear fallout; Cereals; Grass
Abstract: In 1986, 15 farms in the Chernobyl-affected area of the county of Gävleborg were investigated for radiocaesium transfer to grass and cereal grain. The soil surface layer (0–5 cm) in 1986 and the crop products in 1986–1994 were analysed. The aim was to study the impact of site and soil characteristics on sensitivity of 137Cs transfer in a long-term perspective. The transfer was much higher to grass than to cereal grain. For both crop products, however, there was a considerable annual reduction. For grass, and especially in the fallout year 1986, the transfer depended on interception capacity of the stubble and grass sward, on soil fertility and K-fertilization as well as on dilution by crop growth. In the following years, the annual reduction in transfer to grass was reduced by a factor of 2 to 100. Both ploughing through the surface layer and the mixing of radiocaesium with soil contributed to a decreased transfer of radiocaesium to crops. Thick stubble and grass sward on the grassland sites was the main reason for a lag period of high persistent transfer. The annual reduction was less on organic than on mineral soils. Measures to decrease the transfer to crops are discussed in relation to a new concept to evaluate the long-term behaviour of 137Cs in agricultural environments
URL: http://www.sciencedirect.com/science/article/pii/0048969795050566
Title: Heterogeneity in the distribution of RET/PTC rearrangements within individual post-Chernobyl papillary thyroid carcinomas
Author: Unger, K., Zitzelsberger, H., Salvatore, G.*, Santoro, M.*, Bogdanova, T.*, Braselmann, H., Kastner, P.,Zurnadzhy, L.*, Tronko, N.*, Hutzler, P., Thomas, G.:. J.
Reference: Clin. Endocr. Metab. 89, 4272-4279 (2004)
Keywords:
Abstract: The nuclear disaster that occurred in Chernobyl in 1986 offered the unique opportunity to study the molecular genetics of one human tumor type, papillary carcinoma of the thyroid gland, associated with a specific etiology. We have analyzed RET rearrangements in post-Chernobyl papillary thyroid carcinomas (n = 29), follicular thyroid adenomas (n = 2), and follicular thyroid carcinoma (n = 1) by interphase fluorescence in situ hybridization (FISH) analysis on paraffin-embedded tissue sections. Paraffin sections were microdissected before use to ensure that only tumor was present. Cell nuclei were scored for the presence of a split FISH signal (separated red and green signal) in addition to an overlapping signal. Only cells with either two overlapping signals or one split and one overlapping signal were counted to ensure that only complete cell nuclei had been scored. In total, 23 of 32 cases (72%) showed RET rearrangements diagnosed by FISH interphase analysis. In all cases, the tumors were composed of a mixture of cells with and without ret rearrangement on FISH. In some cases, this distribution was clearly nonrandom because clustering of rearranged cells was detected within the same tumor nodule. Accordingly, only 31% of the cases positive for rearrangement on FISH also scored positive using RT-PCR. These findings suggest that because RET/PTC rearrangements are not present in a majority of tumor cells, either a fraction of post-Chernobyl papillary thyroid tumors are of multiclonal origin, or ret rearrangement is a later, subclonal event.
URL: http://www.ncbi.nlm.nih.gov/pubmed/15356021
Title: Influence of radionuclides distributed in the whole body on the thyroid dose estimates obtained from direct thyroid measurements made in Belarus after the Chernobyl accident.
Author: Ulanovsky, A., Drozdovitch, V.*, Bouville, A.*:
Reference: Radiat. Prot. Dosim. 112, 405-418 (2004)
Keywords:
Abstract: Thyroid dose reconstruction is most accurate when using the results of direct thyroid measurements, in which gamma radiation emitted by radionuclides present in the thyroid and in the remainder of the body is recorded by means of a radiation detector positioned against the neck. A large number of such measurements were performed in Belarus in May-June 1986. Owing to the short half-life of 131I and to the intake and accumulation of caesium radioisotopes (mainly 134Cs and 137Cs) in the body, the thyroid doses derived from thyroid measurements made after the beginning of June 1986 have so far been often considered to be unreliable. To evaluate the influence of the caesium radioisotopes to the signal recorded by an instrument performing measurement of 131I activity in the thyroid, a Monte Carlo method was used to calculate the calibration factors of that instrument. These calculations were made for males of six reference ages: newborn, 1, 5, 10 and 15 years old, and adult. The calibration factors were combined with estimated time-dependent intake functions for 131I and caesium radioisotopes. The fractions of the instrument indications that were due to 131I in thyroid were thus estimated as a function of the age of the subject that was measured and of the time elapsed since the accident. Using this information when processing the thyroid measurements made in May 1986 would improve the accuracy of the thyroid dose estimates, and may make it possible to use a larger proportion of the thyroid measurements made in June 1986.
URL:http://www.ncbi.nlm.nih.gov/pubmed/15494363
Title: : Chromosomal imbalances in post-Chernobyl thyroid tumors.
Author: Richter, H., Braselmann, H., Hieber, L., Thomas, G.*, Bogdanova, T.*
Reference: Thyroid 14, 1061-1064 (2004)
Keywords: childhood thyroid tumors
Abstract: Tissue samples from 60 post-Chernobyl childhood thyroid tumors have been investigated. We used comparative genomic hybridization (CGH) to detect chromosomal gains and losses within the tumor DNA. This is the first CGH study on childhood thyroid tumors. The post-Chernobyl tumors showed chromosomal imbalances in 30% of tumors. The most frequent DNA copy number changes in post-Chernobyl tumors involved chromosomes 2, 7q11.2-21, 13q21-22, 21 (DNA gains), and chromosomes 16p/q, 20q, 22q (DNA losses). Some of these specific alterations detected in post-Chernobyl thyroid tumors (deletions on chromosomes 16p/q and 22q) have previously been reported in thyroid tumors as associated with an aggressive biologic behavior and may therefore also account for the more aggressive phenotype of papillary thyroid carcinoma (PTC) found in post- Chernobyl tumors. Eighteen percent of post-Chernobyl PTC that exhibit RET rearrangements also showed chromosomal imbalances indicating that either additional genetic events are involved in this subset of tumors, or that intratumoral genetic heterogeneity exists in these tumors, suggesting a oligoclonal pattern to tumor development.
URL: http://www.ncbi.nlm.nih.gov/pubmed/15650359
Title: Thyroid cancer has increased in the adult populations of countries moderately affected by Chernobyl fallout.
Author: Mürbeth, St.*, Rousarova, M.*, Scherb, H., Lengfelder, E.*:
Reference: Med. Sci. Monit. 10, 300-306 (2004)
Keywords: Czech Republic
Abstract: The incidence of thyroid carcinoma increased among children affected by Chernobyl fallout. Less evidence exists for a corresponding effect in adolescents and adults. The Cancer Registry of the Czech Republic provides an opportunity to study various determinants of the occurrence of thyroid cancer.
URL: http://www.ncbi.nlm.nih.gov/pubmed/15295858
Title: A radioecological model for thyroid dose reconstrucion of the Belarus population following the Chernobyl accident.
Author: Kruk, J.E.*, Pröhl, G., Kenigsberg, J.I.*:
Reference: Radiat. Environ. Bioph. 43, 101-110 (2004)
doi:10.1607/s 004-0241-z
Keywords: Belarus
Abstract: A radioecological model was developed to estimate thyroid exposures of the Belarus population following the Chernobyl accident. The input of the model includes an extensive data set of the 137Cs activity per unit area deposited during the Chernobyl accident, the rainfall data for different regions of Belarus, the 131I/137Cs ratio in the deposit and the start of the grazing period in Belarus in April/May 1986. The output of the model is the age-dependent thyroid exposure due to the intake of 131I with fresh milk. Age-dependent average thyroid doses were assessed for selected regions of Belarus. The maximum thyroid doses were estimated for the inhabitants of Gomel oblast where the highest deposition was observed among the regions considered here. The lowest doses were estimated for Vitebsk oblast with the lowest level of depositions. The mean exposures for the oblasts of Grodno, Minsk, Mogilev and Brest were very similar. The results were compared with estimations of thyroid exposure that were based on 131I measurements in human thyroids, and they are in good agreement. The model may be used for the assessment of thyroid doses in Belarus for areas where no 131I measurements are available.
URL: http://link.springer.com/article/10.1007/s00411-004-0241-z#
Title: INDIVIDUAL THYROID DOSE ESTIMATION FOR A CASE-CONTROL STUDY OF CHERNOBYL-RELATED THYROID CANCER AMONG CHILDREN OF BELARUS-PART I: 131I, SHORT-LIVED RADIOIODINES (132I, 133I, 135I), AND SHORT-LIVED RADIOTELLURIUMS (131MTe AND 132Te)
Author: Gavrilin, Yuri*; Khrouch, Valeri*; Shinkarev, Sergey*; Drozdovitch, Vladimir†; Minenko, Victor‡; Shemiakina, Elena§; Ulanovsky, Alexander§; Bouville, André**; Anspaugh, Lynn††; Voillequé, Paul‡‡; Luckyanov, Nickolas**
Reference: Health Phys. 86, 565-585 (2004)
Keywords: Chernobyl, thyroid, cancer, children
Abstract: Large amounts of radioiodines were released into the atmosphere during the accident at the Chernobyl nuclear power plant on 26 April 1986. In order to investigate whether the thyroid cancers observed among children in Belarus could have been caused by radiation exposures from the Chernobyl accident, a team of Belarusian, Russian, and American scientists conducted a case-control study to compare cases and controls according to estimated thyroid dose. The primary purpose of this paper is to present detailed information on the estimated thyroid doses, due to intakes of 131I, that were used in the case-control study. The range of the 131I thyroid doses among the 107 cases and the 214 controls was found to extend from 0.00002 to 4.3 Gy, with medians of approximately 0.2 Gy for the cases and 0.07 Gy for the controls. In addition, the thyroid doses resulting from the intakes of short-lived radioiodines (132I, 133I, and 135I) and radiotelluriums (131mTe and 132Te) were estimated and compared to the doses from 131I. The ratios of the estimated thyroid doses from the short-lived radionuclides and from 131I for the cases and the controls range from 0.003 to 0.1, with median values of approximately 0.02 for both cases and controls.
URL: http://journals.lww.com/health-physics/Abstract/2004/06000/INDIVIDUAL_THYROID_DOSE_ESTIMATION_FOR_A.2.aspx
