Calculations of individual doses for Techa River Cohort members exposed to atmospheric radioiodine from Mayak releases.

Time-dependent thyroid doses were reconstructed for over 29,000 Techa River Cohort members living near the Mayak production facilities from I released to the atmosphere for all relevant exposure pathways. The calculational approach uses four general steps: 1) construct estimates of releases of I to the air from production facilities; 2) model the transport of I in the air and subsequent deposition on the ground and vegetation; 3) model the accumulation of I in environmental media; and 4) calculate individualized doses. The dose calculations are implemented in a Monte Carlo framework that produces best estimates and confidence intervals of dose time-histories.

Contemporary Understanding of Radioactive Contamination of the Techa River in 1949-1956.

Analysis of recently available archive materials regarding the liquid radioactive waste storage and reprocessing at the "Mayak" Production Association in 1949-1956 has led to a more accurate reconstruction of radionuclide releases into the Techa River. Radionuclide concentrations in the Techa River water, bottom sediments and floodplain soils in 1949-1951 were reconstructed with the use of a purposely-developed Techa River model. Model calculations agree with the measurements of the specific activity in the river water and bottom sediments conducted since 1951.

Analysis of EPR and FISH studies of radiation doses in persons who lived in the upper reaches of the Techa River.

Waterborne radioactive releases into the Techa River from the Mayak Production Association in Russia during 1949-1956 resulted in significant doses to about 30,000 persons who lived in downstream settlements. The residents were exposed to internal and external radiation. Two methods for reconstruction of the external dose are considered in this paper, electron paramagnetic resonance (EPR) measurements of teeth, and fluorescence in situ hybridization (FISH) measurements of chromosome translocations in circulating lymphocytes.

Reconstruction of long-lived radionuclide intakes for Techa riverside residents: 137Cs.

Radioactive contamination of the Techa River (Southern Urals, Russia) occurred from 1949-1956 due to routine and accidental releases of liquid radioactive wastes from the Mayak Production Association. The long-lived radionuclides in the releases were Sr and Cs. Contamination of the components of the Techa River system resulted in chronic external and internal exposure of about 30,000 residents of riverside villages.

Reconstruction of the contamination of the Techa River in 1949-1951 as a result of releases from the "Mayak" Production Association.

More accurate reconstruction of the radioactive contamination of the Techa River system in 1949-1951 has been made on the basis of refined data on the amounts and the rate of discharge of radionuclides into the Techa River from the Mayak Production Association; this has led to the development of a modified Techa River model that describes the transport of radionuclides through the up-river ponds and along the Techa River and deposition of radionuclides in the river-bottom sediments and flooded areas. The refined Techa River source-term data define more precisely the time-dependent rates of release and radionuclide composition of the releases that occurred during 1949-1951. The Techa River model takes into account the time-dependent characteristics of the releases and considers (a) the transport of radionuclides adsorbed on solid particles originally contained in the discharges or originating in the up-river ponds as a result of stirring up of contaminated bottom sediments and (b) the transport of radionuclides in soluble form.