Biomedical subjects

V Taranenko

Publications and source records attributed to V Taranenko.

4 recordsLinked to original sources

PubMed2004

Absorbed dose rate conversion coefficients for reference terrestrial biota for external photon and internal exposures.

The paper describes dosimetric models that allow the estimation of average radiation exposures to terrestrial biota due to environmental sources in the soil as well as internal uniform distributions of radionuclides. Simple three-dimensional phantoms for 13 faunal reference organisms are specified. The calculation of absorbed dose per unit source strength for these targets is based on photon and electron transport simulations using the Monte Carlo method. The presented absorbed dose rate conversion coefficients are derived for terrestrial reference species. This allows the assessment of internal exposure as well as external photon exposure depending on the nuclide, habitat, target size and environmental contamination. To enable the application of specific radiation weighting factors for alpha-, low energy beta- (E0 < 10 keV), beta- and gamma-radiations, their partial contributions to the total absorbed dose are provided separately. The coefficients for external exposure are listed for organisms living above the ground for an infinite plane source 3 mm deep in soil, as well as for a horizontally infinite volume source uniformly distributed to a depth of 10 cm. Furthermore, the coefficients are also presented for organisms living in a contaminated 50 cm thick soil layer. A multi-layer canopy model for plants is also described. The conversion coefficients are given for 3H, 14C, 40K, 36Cl, 59,63Ni, 89,90Sr, 94Nb, 99Tc, 106Ru, 129,131I, 134,135,137Cs, 210Po, 210Pb, 226Ra, 227,228,230,231,232,234Th, 234,235,238U, 238,239,240,241Pu, 241Am, 237Np and 242,243,244Cm, together with their

Animals↗

PubMed2004

Estimation of internal and external exposures of terrestrial reference organisms to natural radionuclides in the environment.

In this paper, an estimation of the doses absorbed by terrestrial reference organisms due to naturally occurring radionuclides is described. For terrestrial organisms under normal circumstances, external exposure is estimated to be of the order of 0.1-0.4 mGy a(-1), depending on size and habitat, and the main contributor is 40K. Internal background exposures of terrestrial organisms are more variable. Again, 40K is an important contributor giving doses of the order of 0.3 mGy a(-1). The exposures of muscles and plant tissues to uranium, thorium, radium, lead and polonium are lower, but liver, bone and kidney may be exposed at levels of 0.1-1 mGy a(-1) absorbed dose. There can also be significant increases in the received dose under specific environmental conditions as is the case for burrowing mammals that receive relatively high lung doses due to the inhalation of radon and its progeny.

Animals↗

PubMed2003

On an evaluation of external dose values in the Techa River Dosimetry System (TRDS) 2000.

Absorbed doses were determined by thermoluminescence (TL) measurements for bricks from a height of 6 m from the south-western wall of the former mill in Metlino that faced the Techa river. Measurements of the internal beta-radiation and alpha-radiation in the brick samples and of radionuclide activities in soil samples from the Techa river valley were performed. The absorbed dose in bricks due to the natural radiation was derived and subtracted from the total dose in order to obtain the absorbed dose in the bricks caused by anthropogenic sources. The results were combined with results from two previous studies. The absorbed dose in the bricks due to the radiation field after relocation of the Metlino population in 1956 was derived from dose rates in air measured in front of the sampling locations in 1996/1997. Based on these dose rates the dose to bricks was calculated by means of conversion factors from the literature. The absorbed dose accumulated in the bricks in the period 1949-1956 was nearly 80% of the total dose that had been determined by TL measurements. Previously derived conversion factors were applied to obtain an estimate of the gamma dose in air at the former shore of the Techa river. An uncertainty and sensitivity analysis was performed with the program package Crystal Ball. Care was taken to treat statistical and systematic uncertainties separately and to take parameter correlations into account. The resulting distribution for the gamma dose accumulated in the period 1949-1956 at the Techa river shore has a median value of 32 Gy with a 95% confidence interval of 21-45 Gy. This study confirms the corresponding value of 26.6 Gy that is used in the Techa River Dosimetry System (TRDS) 2000.

Adsorption↗

PubMed2003

Verification of external exposure assessment for the upper Techa riverside by luminescence measurements and Monte Carlo photon transport modeling.

An area located in the Southern Urals was contaminated in 1949-1956 as a result of radioactive waste releases into the Techa river by the Mayak Production Association. The external dose reconstruction of the Techa river dosimetry system (TRDS-2000) for the exposed population is based on an assessment of dose rates in air (DRA) obtained by modeling transport and deposition of radionuclides along the river for the time before 1952 and by gamma dose rate measurements since 1952. The aim of this paper is to contribute to a verification of the TRDS-2000 external dose assessment. Absorbed doses in bricks from a 130-year-old building in the heavily exposed Metlino settlement were measured by a luminescence technique. By the autumn of 1956 the population of Metlino had been evacuated, and then a water reservoir was created at the village location, which led to a change in the radioactive source geometry. Radiation transport calculations for assumed environmental sources before and since 1957 were performed with the MCNP Monte Carlo code. In combination with TRDS-2000 estimates for annual dose rates in air at the shore of the Techa river for the period 1949-1956 and contemporary dose rate in air measurements, absorbed doses in bricks were calculated. These calculations were performed deterministically with best estimates of the modeling parameters and stochastically by propagating uncertainty distributions through the calculation scheme. Assessed doses in bricks were found to be consistent with measured values within the uncertainty bounds, while their best estimates were approximately 15% lower than the luminescence measurements.

Beta Particles↗