Genetic diversity in Scots pine populations along a radiation exposure gradient.

Polymorphisms of antioxidant enzymes were studied in the endosperm and embryos of seeds from Scots pine populations inhabiting sites in the Bryansk region of Russia radioactively contaminated as a result of the Chernobyl accident. Chronic radiation exposure at dose rates from 0.8 μGy/h led to a significant increase in the rate of enzymatic loci mutations.

Using an Ecosystem Approach to complement protection schemes based on organism-level endpoints.

Radiation protection goals for ecological resources are focussed on ecological structures and functions at population-, community-, and ecosystem-levels. The current approach to radiation safety for non-human biota relies on organism-level endpoints, and as such is not aligned with the stated overarching protection goals of international agencies. Exposure to stressors can trigger non-linear changes in ecosystem structure and function that cannot be predicted from effects on individual organisms.

Effects of long-term chronic exposure to radionuclides in plant populations.

The results of field studies carried out on different plant species (winter rye and wheat, spring barley, oats, Scots pine, wild vetch, crested hairgrass) in various radioecological situations (nuclear weapon testing, the Chernobyl accident, uranium and radium processing) to investigate the effects of long-term chronic exposure to radionuclides are discussed. Plant populations growing in areas with relatively low levels of pollution are characterized by an increased level of both cytogenetic disturbances and genetic diversity. Although ionizing radiation causes primary damage at the molecular level, there are emergent effects at the level of populations, non-predictable from the knowledge of elementary mechanisms of cellular effects formation.

Effects of chronic exposure in populations of Koeleria gracilis Pers. from the Semipalatinsk nuclear test site, Kazakhstan.

Morphological and cytogenetic abnormalities were examined in crested hairgrass (Koeleria gracilis Pers.) populations inhabiting the Semipalatinsk nuclear test site (STS), Kazakhstan. Sampling of biological material and soil was carried out during 3 years (2005-2007) at 4 sites within the STS.

Effects of radioactive contamination on Scots pines in the remote period after the Chernobyl accident.

A 6 year study of Scots pine populations inhabiting sites in the Bryansk region of Russia radioactively contaminated as a result of the Chernobyl accident is presented. In six study sites, (137)Cs activity concentrations and heavy metal content in soils, as well as (137)Cs, (90)Sr and heavy metal concentrations in cones were measured. Doses absorbed in reproduction organs of pine trees were calculated using a dosimetric model.

Geno-toxicity assay of sediment and water samples from the Upper Silesia post-mining areas, Poland by means of Allium-test.

Genotoxic potential of two environmental compartments (water and sediment) from the Upper Silesia Coal Basin (USCB), Poland were evaluated and compared by employing root meristem cells of Allium cepa. The clear genotoxic effect of water and sediment sampled was shown, with an important contribution of severe types of cytogenetic abnormalities. The most biologically relevant pollutants were revealed through multivariate statistical analysis of relationships between biological effects registered and the environment contamination.

Effects of non-human species irradiation after the Chernobyl NPP accident.

The area affected by the Chernobyl Nuclear Power Plant accident in 1986 has become a unique test site where long-term ecological and biological consequences of a drastic change in a range of environmental factors as well as trends and intensity of selection are studied in natural settings. The consequences of the Chernobyl accident for biota varied from an enhanced rate of mutagenesis to damage at the ecosystem level. The review comprehensively brings together key data of the long-term studies of biological effects in plants and animals inhabiting over 20 years the Chernobyl NPP zone.

Chernobyl radionuclide distribution, migration, and environmental and agricultural impacts.

The distribution and migration of radionuclides released into the environment following the Chernobyl accident in 1986 are described. The Chernobyl disaster resulted in the consumption of farm products containing radionuclides as a source of irradiation of the population due to the prevalence of a rural type of human nutrition in the affected region. Economic and radiologic importance of countermeasures for reducing the impacts of the accident are described.

Effects on non-human species inhabiting areas with enhanced level of natural radioactivity in the north of Russia: a review.

Results of long-term radioecological investigations in areas with an enhanced level of natural radioactivity in the north of Russia are summarized. Deleterious changes within animal and plant populations inhabiting areas with an enhanced level of natural radioactivity in the Komi Republic were revealed. These changes are expressed in enhanced levels of mutagenesis, destructive processes in the tissues of animals, disturbances of reproductive functions and reduced offspring viability.

Cytogenetic effect of low dose gamma-radiation in Hordeum vulgare seedlings: non-linear dose-effect relationship.

The induction of chromosome aberrations in Hordeum vulgare germinated seeds was studied after ionizing irradiation with doses in the range of 10-1,000 mGy. The relationship between the frequency of aberrant cells and the absorbed dose was found to be nonlinear. A dose-independent plateau in the dose range from about 50 to 500 mGy was observed, where the level of cytogenetic damage was significantly different from the spontaneous level.

Cytogenetic effects of combined radioactive (137Cs) and chemical (Cd, Pb, and 2,4-D herbicide) contamination on spring barley intercalar meristem cells.

The frequency of cytogenetic effects in spring barley intercalar meristem cells was studied in the presence of a range of different stressors. There was a non-linear dependence on the concentrations of 137Cs, Cd, Pb, and dichlorophenoxyacetic acid (2,4-D) herbicide contamination in the exposure ranges used. The frequency of cytogenetic effects increased at the lower concentrations of the pollutants more rapidly than at the higher concentrations.

Bio-monitoring the genotoxicity of populations of Scots pine in the vicinity of a radioactive waste storage facility.

Results of a long-term (1997-2002) study of the Scots pine populations growing in the vicinity of the radioactive waste storage facility ('Radon' LWPE) are presented. Cytogenetic disturbances in reproductive (seeds) and vegetative (needles) tissues sampled from Scots pine populations were studied to examine whether Scots pine trees have experienced environmental stress in areas with relatively low levels of pollution. The data clearly indicate the presence of mutagenic contaminants in the environment of the pine trees.

Bioavailability of radiostrontium in soil: experimental study and modeling.

Parameters related to 90Sr mobility in the soil-plant system are reported: exchangeable content, selectivity coefficient, and transfer factor. Large mobility of 90Sr in different soil types was shown. The fraction of exchangeable 90Sr varied between 70 and 90%.

Comparative radiation impact on biota and man in the area affected by the accident at the Chernobyl nuclear power plant.

A methodological approach for a comparative assessment of ionising radiation effects on man and non-human species, based on the use of Radiation Impact Factor (RIF) - ratios of actual exposure doses to biota species and man to critical dose is described. As such doses, radiation safety standards limiting radiation exposure of man and doses at which radiobiological effects in non-human species were not observed after the Chernobyl accident, were employed. For the study area within the 30km ChNPP zone dose burdens to 10 reference biota groups and the population (with and without evacuation) and the corresponding RIFs were calculated.

[Long time combined action of cadmium and ultraviolet radiation on barley plants].

In a greenhouse experiment the development of biomass and grain yield was studied under a long-time combined action of medium-wave UV-radiation and cadmium (exposure levels of the agents were, respectively, 0.65-1.30 W/m2, 5 and 50 mg/kg of soil).

[Development of a strategy for countermeasures application aimed at remediation of consequences of radioactive contamination of forest ecosystems].

The radiation situation has been assessed in forest ecosystems of the most affected by the Chernobyl accident region of the Russian Federation--Novozybkov district of the Bryansk region. Using a set of migration models and methods for estimating doses of external and internal irradiation of the population, predictive calculations have been made that demonstrated a need to implement countermeasures in forest ecosystems of the region. A strategy of countermeasures application was developed based on a conservative approach, which postulates priority of observance of the sanitary-hygienic standard--permissible exposure level for the population and need for invoking the economic indicators to optimize countermeasure option.

[Radiation protection of the environment: anthropocentric and eco-centric principles].

The second half of the XX century was dominated in the field of radiation protection of the environment by the anthropocentric concept stated by the International Commission on Radiological Protection (ICRP). According to this concept "if man is adequately protected by radiological standards then biota are also adequately protected". At the end of the XX--beginning of the XXI centuries in the area of area of radiation protection of nature an ecocentric strategy is beginning to develop where emphasis has swung to the protection of biota in their environment.

[The radiation-increased synthesis of phytochelatins in roots of gamma-irradiated barley seedlings].

It was shown that gamma-irradiation and cadmium nitrate increased synthesis of phytochelatins in roots of barley seedlings. The stimulation of synthesis of phytochelatins in gamma-irradiated plants was shown for the first time. The results obtained indicate more important role of phytochelatins in intercellular metabolism than heavy-metal-binding.

[Effects of gamma-irradiation on broiler-6 and Leghorn chicken].

The influence of various doses of external radiation to survive, growth and productivity of hybrid broiler and egg-laying leghorn chicken was studied in comparative aspect. It was found that broiler radio-resistanse is 1.5 times higher than that of leghorns: LD50/30 of 10-days broilers is equal to 16.

[Effects of gamma-irradiation on the cardiovascular system of sheep].

In experiments with sheep, the response of the vascular system of the mammals to the total exposure dose was studied. A dose increase resulted in a more pronounced impairment of contraction of the cardiac muscle. In response, a compensatory reaction of the peripheral vessels was intensified up to LD50/30.

Bioindication of the anthropogenic effects on micropopulations of Pinus sylvestris, L. in the vicinity of a plant for the storage and processing of radioactive waste and in the Chernobyl NPP zone.

Results of a comparative analysis of the frequency and spectrum of cytogenetic anomalies are presented for reproductive (seeds) and vegetative (needles) samples taken from Scotch pine (Pinus sylvestris, L.) micropopulations growing at sites with differing levels of radioactive contamination in the Chernobyl NPP 30 km zone, and at the location of a facility for the processing and storage of radioactive wastes (the 'Radon' LWPE, near the town of Sosnovy Bor in the Leningrad Region). The data obtained indicate the presence of genotoxic contaminants in the environment of the tree micropopulations.

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.

[Reconstruction of I-131 in milk and exposure doses to the thyroid gland of cattle after the Chernobyl AES].

Suggestions are made concerning the restoration of 131I content in cow milk of six districts in the Gomel region based on radiometric measurements of the overall activity of milk samples in the iodine period of the Chernobyl NPP accident, reconstruction of doses to thyroid of cattle and calculation of dose distribution among the live-stock by separation the function of activity changes in milk samples in time into the basic components formed by the contribution of 131I, 134Cs and 137Cs. The best approximation to the description of the function of milk activity variations was found to be achieved by the representation of forage activity changes as a sum of exponents with the half-life periods of 5 and 30 day with a partial contribution of 0.8 and 0.

[Analysis of factors determining the biological availability of 137Cs in forest ecosystem soils].

On five forest plots varying in species composition of woody plants and soil properties, 137Cs accumulation by vegetation of the forest understorey has been studied. Differences in 137Cs availability for root uptake are shown to be dependent on a vertical distribution of 137Cs content over the soil profile, percentage of exchangeable 137Cs and distribution of plant root systems (fungous mycelium) in soil. A 137Cs-bioavailability index is suggested and its non-linear relationship with 137Cs transfer factors to different plant species in the understorey is shown.

[Effect of combined radioactive and chemical (heavy metals, herbicides) pollution on the yield of cytogenetic disruptions in the intercalary meristem of spring barley].

The yield of aberrant cells and their loading with lesions of intercalary meristem of spring barley in conditions of the combined action of 137Cs, heavy metals and 2.4-D herbicide was studied. At simultaneous insertion of 137Cs and Cd into the soil, the type of non-linearity of the yield of aberrant cells was determined by radioactive pollution: in a range of low concentrations the synergistic effects took place, in a range of higher ones the antagonistic effects did.