The main radionuclides and dose formation in fish of the Chernobyl NPP exclusion zone

The results of the researches of spices-specificity, accumulation dynamics and distribution of 90Sr, of 137Cs and of transuranic elements in fish of the Chernobyl NPP exclusion zone are analysed. The data of estimations of absorbed doze rate from incorporated radionuclides for pray fish and predatory species are given. For the fish from the lake of the left-bank floodplain of the Pripyat River the increase of 90Sr specific activity is registered which is presumably connected with the dynamics of the physical-chemical forms of the radionuclide in soils and their wash out in water bodies from the catchment basin. Now about 90% of internal dose rate of fish from closed aquatic ecosystems within the Chernobyl NPP exclusion zone is caused by 90Sr incorporation.     

Plutonium at the ecosystems of impact zone the Beloyarsk NPP

The distribution of the plutonium at the ecosystems of impact zone the Beloyarsk NPP was studied. Higher quantity of Pu (to 500 Bq/m2) was revealed in the bottom sediments of the Olkhovsk bog where low-level radioactive water of the Beloyarsk NPP have been discharged. The total amount of the radionuclide in a soil cover did not exceed 140 Bq/m2. The contribution of the Beloyarsk NPP to contamination of the investigated ecosystems was accounted with using ratio 238Pu/239.240Pu. It was 64.1-99.3% both in the bottom sediments and soils.     

The agroecosystems flora status in restricted zone 20 years after the Chernobyl NPP accident

The article presents the results of studying on agroecosystems flora status in restricted zone 20 years after the Chernobyl accident. There were preliminary identified 8 agroecosystems associations by Broaun-Blanquet ecologo-floristic classification: Phalacrolometum septentrionale, Agrostio tenuis Calamagrostietum epigeii, Agrostio tenuis--Elytrigietum repentis, Poo pratensis--Bromopsietum inermis, Poo pratensis--Dactylidetum glomeratae, Poo pratensis--Agrostietum tenuis, Elytrigio repentis--Poetum pratensis, Caricetum hirtae. First three associations were attributed to Agropyretea repentis class, to Agropyretalia repentis order, Convolvulo--Agropyrion union. We consider the association Phalacrolometum septentrionale as the initial stage of agroscosystems overgrowing which is continued with increase of its demonstration in association Agrostio tenuis--Calamagrostietum epigeii and Agrostio tenuis--Elytrigietum repentis. The associations Poo pratensis--Bromopsietum inermis, Poo pratensis--Dactylidetum glomeratae, Poo pratensis--Agrostietum tenuis and Elytrigio repentis--Poetum pratensis we attributed to class Molinio--Arrhenatheretea, to order Arrhenatheretalia and Festuncion pratensis union. The association Caricetum hirtae was attributed to class Plantaginetea majoris, to order Plantaginetalia majoris and to union Agrapyro--Rumicion crispi. For each of the allocated associations and rye sowing there was provided brief characteristic, including 137Cs and 90Sr radionuclids content in soil and air-dry herbage mass. During the period of studies there was marked stable soil and air-dry herbage mass contamination by radionuclides at absence of grass stabilization of studied agroecosystems. The limiting factor on using of meadow agroecosystems herbages is their high level of contamination by 90Sr. The herbage can be used only for obtaining of milk-raw material for processing.     

Radioecological problems of aquatic ecosystems of the chernobyl exclusion zone

The dynamics of the main contaminating radionuclides in the components of aquatic ecosystems within the Chernobyl APP exclusion zone is considered. The possible causes are analyzed for the marked increase in the specific activity of ⁹⁰Sr in water and hydrobionts of the lakes at the dammed left bank of river Pripyat. Notable is the elevated frequency of chromosomal aberrations in the root meristems of aquatic higher plants (up to 17%) and in the embryonal tissues of gastropod mollusks (up to 27%), alterations in the hematological indices for gastropods, and high infestation of aquatic higher plants by parasitic fungi and gall arthropods in the most radiocontaminated reservoirs.     

Radiation and genetic consequences of ionizing irradiation on population of Pinus sylvestris L. within the zone of the Chernobyl NPP

Main results of the nineteen year radiation-genetic monitoring of radiobiological, of cytogenetic, and of genetic parameters of Pinus sylvestris L. of forest plantation from the Chernobyl meltdown area are presented. The acute ionizing irradiation at doses >1 Gy induces the formation of morphoses and of depressed growth; at doses >2 Gy, the reproductive ability of the trees declined. The radiobiological parameters shown linear or close to it dose-dependence relationship. The acute irradiation at dose of 0.5 Gy induces cytogenetic and genetic effects that were significantly higher than the corresponding control values. The relationship between the cytogenetic effects and the absorbed dose was exponential. The dependence of mutation frequency at specific loci on the absorbed dose was described by a nonlinear curve. The results of the cytogenetic analysis of seedlings obtained from seeds annually collected in zones of slight, of moderate, and of strong damage of Pinus sylvestris L. are presented.     

Force field measurements within the exclusion zone of water

Water molecules play critical roles in many biological functions, such as protein dynamics, enzymatic activities, and cellular responses. Previous nuclear magnetic resonance and neutron scattering studies have shown that water molecules bind to specific sites on surfaces and form localized clusters. However, most current experimental techniques cannot measure dynamic behaviors of ordered water molecules on cell-size (10 μm) scale. Recently, the long-distance effect of structured water has been demonstrated by Pollack and his colleagues. Namely, there is a structured water layer near the hydrophilic surface that can exclude solutes (Zheng et al, Adv Colloid Interface Sci 127:19–27, 2006; Pollack 2006, Adv Colloid Interface Sci 103:173–196, 2003). The repelling forces of water clusters inside this exclusion region are investigated in this study. With a laser tweezers system, we found the existence of an unexpected force fields inside the solute-free exclusion zone near a Nafion surface. Our results suggest that the water clusters could transduce mechanical signals on the micrometer range within the exclusion zone. This unexpected inhomogeneous force field near the hydrophilic surface would provide a new insight into cellular activities, leading to a potential new physical chemistry mechanism for cell biology.     

Strontium-90 and caesium-137 activity concentrations in bats in the Chernobyl exclusion zone

Bats are a protected species and as such may be an object of protection in radiological assessments of the environment. However, there have previously been only few radioecological studies of species of bats. In this paper, results for >140 measurements of ⁹⁰Sr and ¹³⁷Cs in 10 species of bats collected within the Chernobyl zone are presented. There was some indication of a decreasing transfer of ⁹⁰Sr with increasing deposition, although this was inconsistent across species and explained little of the observed variability. There was no difference between male and female bats in the transfer (expressed as the ratio of whole-body activity concentrations to those in soil) of either radionuclide. There was considerable variability in transfer across all species groups. At two sites where there were sufficient data, Eptesicus serotinus was found to have higher transfer than other species.     

Sexual function of male rats exposed to the factors of the Chernobyl exclusion zone

The influence of chronic internal and external irradiation in low doses on sexual behavior and fertility of sexual active animals keeping within the 30-km Chernobyl exclusion zone was studied. After the 1.5 month consumption of drinking water containing radionuclides of natural Chernobyl spectrum the decrease in proportion of sexual active animals and suppression of sexual motivation and erection were observed. This deviations resulted in the reducing of the inseminated females number. The dependence between the magnitude of total absorbed dose and the working of the sexual behavior regulative mechanisms was obtained. In addition, the reduction of rat fertility took place because of the increase of preimplantation, but not post-implantation death in in irradiated females coupled with irradiated males. The irradiation of males with total absorbed dose on testis 0.23 cGy decreased the fertility because of sexual behavior disturbance, and this effect was intensified by negative influence of ionizing radiation in the range of 0.7-7.0 cGy on male gametes.     

The distribution of microcrustacea in the littoral zone of a freshwater lake

The distribution of microcrustacea in the water column, sediments and on different macrophyte species was examined in the littoral zone of Jack Lake, Nova Scotia, Canada. Large numbers of microcrustacea occurred in association with macrophytes, suggesting that this habitat should receive greater attention in future studies of microcrustacean numbers, biomass, and production. The relative abundance of different microcrustacea varied considerably among sediments, macrophytes and water column samples. Although microcrustacean species composition differed among macrophyte groups, consistent differences in absolute numbers per gram could not be demonstrated. Epiphytic microcrustacean community structure also varied among depth strata in Jack Lake. Few epiphytic and benthic microcrustacea migrated into the water column on a diurnal basis.     

A comparative analysis of the impact on biota and man in the 30 km zone of the Chernobyl NPP

A methodological approach is described for a comparative assessment of ionizing radiation effects on man and biota, based on the use of indices of radiation impact--ratios of actual exposure doses to environmental objects (including humans) and critical ones. As such doses, standards limiting radiation exposure and doses at which phenotypical effects were absent after the Chernobyl accident were employed, respectively for man and biota. For the test site chosen within the 30 km ChNPP zone (region of the Borshchovka settlement), dose burdens to reference biota species and the population (with and without evacuation) and the corresponding radiation impact indices were calculated. For the long term period after the accident radiation safety standards for man are shown to ensure radiation safety for biota as well. At the same time in the early period after the accident the emergency regulations do not guarantee adequate protection of nature, some species of which can be subject to irradiation more than man, even if countermeasures like evacuation are not applied. A conclusion has been made on the necessity of a more detailed and comprehensive analysis of situations when the anthropocentric principle "if radiation standards protect man then biota are also adequately protected" is violated.     

Long-term follow-up cytogenetic survey and biological dosimetry in persons evacuated from 30-km Chernobyl NPP zone

The paper presents the results of the follow-up cytogenetic survey and biological dosimetry carried out in inhabitants of Pripiat' town and nearby villages, who were departured from the Chernobyl NPP 30-km exclusive zone during first days after the Chernobyl catastrophe. The unstable chromosome aberration level in inhabitants were significantly increased above control in terms up to 1 year after evacuation and declined gardually during next 14 years. In early period the cytogenetic damage frequency in evacuees showed no dependence on gender. The chromosome type aberration level appeared to be lower in young persons comparing with adults. The dicentrics plus centric rings yield had a positive correlation with duration of staying at Chernobyl zone. The average doses of protracted exposure were calculated from the dicentrics and centric rings yields; the dose estimations appeared to be 1.4 times higher in persons evacuated 3-11 days after the accident than that of in persons with shorter departure time. Uing the Bayesian analysis the probabilistic distribution of biological doses was constructed for the studied evacuees group. This distribution was characterized by a mean dose of 360 mGy, the modal doses of 200-450 mGy and 80% of probability density within the dose range 0-1000 mGy, that seems to be sufficient for considering the increased risk of late somatic radiation effects for this cohort.     

The radioactive contamination dynamics of water body ecosystems of different types in the Chernobyl atomic station alienation zone in Belarus

The long-term (1986-2005) gamma-activity dynamics in dominating zoobenthos species and the bottom sediments in the inlet of Pripyat river and the non-flowing Perstok lake within the Chernobyl alienation zone was determined. Immediately after the accident (1986-1987) zoonehthos y-activity achieved the maximal values (up to 300-1100 kBq/kg) and after that began to decline steadily due to natural decay of man-caused radionuclides of "Chernobyl origin". Up to summer 2005 gastropod mollusks gamma-activity (Lymnaea stagnalis, Viviparus viviparus) approached to the natural level (less than 6 Bq/kg) in the inlet of Pripyat river, but it remained at the very high level up to 979-1638 Bq/kg in the Perstok lake. The positive correlation between gamma-activity of mollusks and bottom sediments has been established. In turn, the long-term variations of atmospheric precipitate amounts which wash down radionuclides from surrounding territories to water bodies and the amounts of annual flow of the Pripyat river as well as shoreline position changes in water bodies within the Chernobyl alienation zone influence on these values too.     

Effects of chronic irradiation of Scots pine (Pinus sylvestris L.) in Chernobyl exclusion zone

The quantitative "dose rate-effect" dependences are presented for the cytogenetic damages in the seedlings and apical meristem of Scots pine growing in the Chernobyl zone. The specific patterns of dynamics of formation of the morphological effects in the studied species are considered for the conditions of the internal and external chronic irradiation. The correlation dependencies are established for the irradiation effects appearing at the morphological and cell level. The assumption concerning the mechanism of the morphological changes formation is done.     

The dose estimation of woody plants in the long-term after the Chernobyl NPP accident

Dosimetric models have been developed to estimate the exposure doses of woody plants growing in the area contaminated by long-lived radionuclides. The models are parameterized based on the data obtained from the experimental plots in the south-west districts of the Bryansk region affected by radioactive fallout of the Chernobyl NPP accident. Doses are estimated to generative organs of pine trees from these plots. The contribution from various sources and types of ionizing radiation to the absorbed dose formation for these objects is determined.     

Effect of factors from the Chernobyl exclusion zone on the level of cytochrome P-450 in mouse liver microsomes

The data concerning the influence of Chernobyl exclusive zone factors on cytochrome P-450 relative contents in liver microsome fractions of Balb/c, CC57W/Mv and C57 Black mice are submitted in this work Reliable diminishing of liver P-450 relative concentration in experimental animals, compared with respective isogenic control groups is shown to be varying depending on the mouse line and sex.     

Radiation-induced changes in the genome of pine seeds, forming under conditions of chronic irradiation in the Chernobyl exclusion zone

Comparative study of long-term existing genome damages in the chronically irradiated pine seeds from different parts of Chernobyl zone have been performed by a pulsed field gel electrophoresis and hydroxyapatite chromatography. Some differences were established for DNA degradation kinetic from protoplasts with various accumulated doses of irradiation. Results obtained could testify the existence of long-living changes in the experimental plants genome.     

Chernobyl radionuclides outside the boundaries of the USSR. The European continent]

The reports on radiation sequels of Chernobyl disaster outside the country are scanty in the USSR. The present paper meets the lack, reporting the scale and the nature of the radioactive fall-outs outside the USSR. The analysis is made of possible radiological consequences of such fall-outs and the preventive measures taken by the governments of some European countries.     

Participation of the lipid peroxidation processes in the adaptation mechanism of Muridae like rodents to the radioactive contamination of the Chernobyl NPP zone

Results of the comparative analysis of the complex investigation of rodent population state caught at areas with different levels of contamination in the accident zone of the Chernobyl NPP during 1986-1993 and 2007, at areas with a practically normal radiation background in the neighborhood of the Kiev City in 1993 and at areas with the normal and increased radiation background in Ukhta region of Komi Republic in 1993-2008 are presented. It is shown that the absence of the linear dependence in changes of the lipid peroxidation (LPO) regulatory system parameters in rodent tissues on the dose of the external gamma-radiation at areas of their trap persists for a long time. Different ability to normalization of the studied indices and nonlinearity of their dose dependences allow us to suggest that changes of the scale and direction of interrelations between the reciprocal parameters of the LPO regulatory system in norm in tissues of rodents which were caught in the accident zone and at areas with an increased radiation background should be the information signal determining selection of the strategy of adaptation to the chronic radiation factor action.     

The ecosystems approach to water management. The main features of the ecosystems concept

This paper summarizes the conceptual basis for ecosystemic water management, principally as it is discernible through a series of discussion papers contributed to the UN/ECE Seminar held in Oslo in May, 1991. The ecosystems approach seeks the objective management of water quality in lakes and river catchments, the sustainable exploitation of water resources (sensu lato) and the maintenance of biodiversity within aquatic catchments. It also seeks an attitude founded upon the sharing of habitat with other ecosystem components and the minimization of human impact. Moreover, there is no final condition: rather, there is an ethos always to improve performance. Emphasis is nevertheless placed on the unevolved, subclimactic state in which many ecosystems find themselves and the elasticity of structure which this imparts and which may, within limits, be exploited. Methods for assessing environmental quality and for measuring the performance of corrective management are briefly discussed. Future progress is suggested to be less than easy but proper ecosystemic attitudes and approaches are seen to be essential ingredients if past mistakes are to be overcome.