|Techa River: Nuclear disaster along the Techa River (Southern Urals, Russia)|
The nuclear-industrial complex known as Mayak Production Association (PMA) was constructed in May 1946 in the province of Cheryabinsk (Southern Urals). MPA was comprised of a radiochemical separation plant (Facility B), isotope plants and uranium-graphite reactors (Facility A), and started the production of weapon-grade plutonium in 1948. The drainage of the area is primarily via Techa River (237 km length). The radiation exposures to the inhabitants alongside the Techa River were in complex pictures.
(1) Discharge of radioactive wastes: While
natural lakes and dammed ponds at the plant site were employed as reservoirs
to manage radioactive effluents, direct discharges of large amount of radionuclides
to the Techa River system occurred between 1949 and 1956; approximately
98% of the total radioactivity being released during 1949-1951. For instance,
over 100 PBq of radioactive material was discharged during the whole period,
causing severe contamination down the entire length of the Techa River.
Of the total activity, ruthenium isotopes (103Ru, 106Ru)
account for over 50% and estimated 12 PBq of 90Sr, 13 PBq of 137Cs,
and alpha emitters (Pu and U isotopes) of 2 TBq were discharged during
1949-1957. The Techa River system was only water source for the residents of
the riverside villages. A total of 124,000 people received external exposure
from 137Cs, 106Ru, 95Zr and other
radionuclides, and internal exposure from ingestion of 89Sr, 90Sr
and 137Cs as well. It has been estimated that about 8% of this population
received doses higher than 1 Gy.
With these nuclear disasters, a large number of residents of the riverside area have been exposed externally to 137Cs and internally predominantly to 90Sr. In 1952, the discharge of radioactive wastes into the river was prohibited. At the same time, the utilization of river water for living and industry use was prohibited and people were evacuated. (cited from Salassidis et al., Int. J. Radiat. Biol., 74:431-439, 1998; Testa et al., Mutation Res., 401:193-197, 1998).
Excess cancer occurrence has been noticed
in the riverside people as early as in 1960. It called international interest
first in 1990, when Japan-USSR binational symposium was held in Tokyo,
25-29 June, 1990 and later in the International Symposium on "Chronic
radiation exposure: Risk of late effects", Cheryabinsk, 9-13 January,
| Techa River: Inhabitant along the river (Bauchinger et al. 1998)|
Chromosome aberration analysis
Lymphocyte chromosome analysis was carried
out in 73 radiation-exposed residents from villages along the Techa River
located 7-148 km downstream the site of discharge of radioactive waste
from the plutonium production facility of Mayak. Chromosome aberrations
were studied by FISH painting using whole chromosome painting probes of
chromosomes 1, 4 and 12. Blood sampling was made during the years between
1994 and 1996. Thirty-nine unexposed persons from non-contaminated areas
were used as controls.
Bauchinger, M., Salassidis, K., Braselmann, H., Vozilova, A., Pressl, S., Stephan, G., Snigiryova, G., Kozheurov, V. P. an Akleyev, A. (1998): FISH-based analysis of stable translocations in a Techa River population. Int. J. Radiat. Biol., 73:605-612.
Dose evaluation in villages along the Techa River
|Village||Distance from||No. of persons||No. of cells||Absorbed dose (Gy)|
|(settlement)||the site of release (km)||studied||scored||external (1945-1956)||RBM (external+internal, for 25 yrs)|
|.Chromosome aberration frequencies as revealed by FISH-painting|
|Groups/distance||No. of persons||Year od birth||No. of cells||FG translocation per 1000|
|Group I: 7-60 km|
|Group II: 78-148 km|
|Total (Groups I + II)||73||1936}10||36,520||12.8}1.5|
Commentary added at compilation of data
Figure 1A is reproduced from the scattered plots of FG translocation frequencies presented by the authors for persons from the villages 7-148 km downstream from the waste discharge as plotted against red marrow dose (RBM dose). They concluded that the aberration frequencies were significantly elevated and were within the limits of 95% prediction levels of the in vitro linear dose-response relationship. The dose-dependent increase is more clearly seen when the data are smoothed by moving window averaging, MWA=(w5,s1), as seen in Figure 1B.
| Techa River: Inhabitants (Akleyev et al. 1995)|
|Chromosome aberration analysis|
Research was collaborative study between
Ural Research Center for Radiation Medicine (URCRM), Chelyabinsk, Russia,
and Radiation Effects Research Foundation (RERF), Hiroshima, Japan, was
conducted 43 years after the beginning of radioactive waste discharge to
Techa River. The study cohort was selected from persons cumulative doses
accounting for radionuclides 90Sr and 137Cs
in 90-95% of cases. The dose to the red bone marrow (RBM) was reconstructed from
the dose rate throughout the follow-up period and the measurement of whole body
Akleyev, A. V., Kossenko, M. M., Silkina, L. A., Degteva, M. O., Yachmenyov, V. A., Awa, A., Akiyama, M., Veremeyeva, G. A., Vozilova, A. V., Kyoizumi, S., Kozheurov, V. P. and Vyushkova, O. V. (1995): Health effects of radiation incidents in Southern Urals. Stem Cells, 13 (Suppl. 1):58-68.
|Group||Mean cumulative||No. of||Age||No. of||FG, Tr/cell|
|RBM dose (Sv)||persons||Mean and range||cells||(Mean}m)|
|Exposed||Group I||0.82 (below 1.0)||8||62.5 (51-73)||4,000||0.021}0.004|
|Group II||1.51 (1.0-1.99)||19||64.7 (52-82)||9,500||0.024}0.003|
|Group III||2.38 (2.0 and higher)||7||57.0 (55-59)||3,500||0.032}0.005|
|Group IV*||1.76 (1.20-2.66)||11||62.2 (54-81)||3,500||0.027}0.004|
|Total||1.52 (0.28-2.66)||34||62.6 (51-82)||17,000||0.025}0.002|
|Comparisons (controls)||0||10||65.7 (54-84)||5,000||0.031}0.007|
|*) Group of persons showing chronic radiation sickness (CRS).|
|Commentary added at compiling the data|
Figure A is the scattered plots of the translocation frequencies, replotted from Figure 10 of Akleyev et al. 1995, indicating no positive correlation with the RBM dose. Figure B shows the data smoothing by moving window averaging, MWA=(w5s1), of the same data. The dose-response is suggestive.
| Techa River: Children (Testa et al. 1998)|
|Chromosome aberration analysis|
Fifteen children born and raised in riverside
village Myslyumovo (78 km from the site of radioactive waste discharge)
subjected to radioactive contamination over a period of 45 years. They
came to Italy for a one-month stay, where they underwent medical check.
Blood sampling was carried out to examine chromosome aberrations. Control
group consisted of 11 Russian children (10-14 yrs old) from uncontaminated
locality of Smolensk (Russia) which had been selected for previous study
on the Chernobyl accident (Padovani et al. Mutation Res., 395:249-254, 1997).
Testa, A., Padovani, L., Mauro, F., Appolloni, M., Anzidei, P. and Stronati, L. (1998): Cytogenetic study on children living in Southern Urals contaminated areas (nuclear incidents 1948-1967). Mutation Res., 401:193-197.
|Subject||Sex||Age||No. of||Chromosome aberrations||Subject||Sex||Age||No. of||Chromosome aberrations|
|*) Excess acentrics: include acentric rings, minutes and fragments||.|
| Techa River: Residents living upper reach (Degteva et al. 2005, 2015; Vozilova et al. 2012)|
Degteva, M. O., Anspaugh, L. R., Akleyev, A. V., Jacob, P., Ivanov, D. V., Wieser, A., Vorobiova, M. I., Shishkina, E. A., Shved, V. A., Vozilova, A., Bayanskin, S. N. and Napier, B. A. (2005): Electron paramagnetic resonance and fluorescence in situ hybridization-based investigations of individual doses for persons living at Metlino in the upper reaches of the Techa river. Health Phys., 88:139-153.
External dose was estimated by electron paramagnetic resonance (EPR) on teeth enamel obtained from 16 exposed donors born between 1928 and 1952 in Metlino (7 km from the release site). Metllino is the closest village to the site of release. The residents were exposed both externally to gamma-rays from the contaminated river bank and internally from dietary intake of radionuclides (89/90Sr). In the residents of Metlino, the external dose is estimated to contribute up to 45% of the total red bone marrow dose. In this study, a total of 36 EPR measurements were performed; 13 at the Institute for radiation protection, GSF-National Research Center for Environment and Health, Munich, Germany (GSF), and 20 at the Institute of Medical Physics, Ekaterinburg, Russia (IMP). The inter laboratory comparison of EPR dosimetry systems was made on the same samples obtained from Ural donors.
Chromosome analysis was carried out on peripheral lymphocytes from 31 exposed persons (residents of Metlino born between 1918 and 1953). Blood samples were collected between 1994 and 1998. Lymphocyte culture and chromosome preparation were made at the Urals Research Center for Radiation Medicine (URCRM), and FISH analysis was performed at GSF. Whole chromosome-painting probes for chromosomes 1, 4 and 12 were used together with pancentromeric probe.
Chromosome translocations and EPA measures of external dose (c.f., Genome equivalent frequencies, FG(Tr), were calculated and shown in figure at the time of data compiling.)
|Degteva, M. O., Shagina, N. B., Shiskina, E. A., Vozilova, A. V., Volchkova, A. Y., Vorobiova, M. I., Wieser, A., Fattibene, P., Della Monnaca, S., Ainsury, E., Moquet, J., Anspaugh, L. R. and Napier, B. A. (2015): Analysis of EPR and FISH studies of radiation doses in persons who lived in the uppr reaches of the Techa River. Radiat. Environ. Biophys., 54:433-444.|
|Blood sampling was conducted in 2009-2013 for the residents of upper reach of the Techa River. Lymphocyte translocation frequencies (stable-type) were studied by FISH painting method. The frequencies were compared with the estimated external doses and the dose to the tooth enamel evaluated by electron paramagnetic resonance (EPR) assay. Basically there was a reasonable agreement among chromosomally estimated dose, external dose and EPR dose.|
|Group||Settlement||Distance from||No. of||External dose of||EPR-based dose*||GE cells**||No. of|
|release site (km)||persons||reference person (mGy)||(mGy)||scored||translocations|
|II||Techa Brod, Asanovo, Nazarovo,||18-45||13||150-400||223}83||9,358||204|
|Maloe Taskino, Gerasimovka, GRP|
|II||Nadyrov Most, Nadyrovo||48-50||12||100-200||569}250||9,177||273|
|IV||Ibragimov, Isaevo, PHT||54-70||34||80-120||160}60||16,248||333|
|*) To evaluate EPR-based dose to enamel, the anthropogenic dose was modified by the 90Sr concentration-to-dose converstion factors for different tooth positions.|
|**) Genome-equivalent cells scored.|
Vozilova, A. V., Shagina, N. B., Degteva, M. O., Anisbury, E. A., Moquet, J. E., Hone, P., Lloyd, D. C., Fominar, J. N. and Darroudi, F. (2012): Preliminary FISH-based assessment of external dose for residents exposed on the Techa river. Radiat. Res., 177:84-91.
Blood samples were collected from 18 persons
residing in middle Techa regions, and translocation frequencies were studied
by FISH paining method three laboratories; Urals Research Center for Radiation
Medicine (URCRM), Health Protection Agency (HPA), UK, and Leiden University
Medical Center (LUMC).
A weak, but significant linear dependency to the RBM 89/90Sr dose. The dose to the individual subject was not given in the report. (Figure is reproduced from Fig. 1 of Vozilova et al., 2012).