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Time of growth of Plants (days)

Fig 7. Dynamics of Growth of Root Plants in Control (X) , under action of Cd (͏) and after action of gamma-irradiation ( ǻ)

The experiments have shown, that the external gamma-irradiation provokes a noticeable decrease of tracer (137Cs) accumulation in rooted and overground biomass of plants during growth.(Fig 6,7). It turns out that the larger is the dose, the smaller is the biota radiocapacity factor in this experimental model. An exact relation was established between the degree of decline of biota and its radiocapacity factor

These researches have shown, that the similar effects are reached both by thermal stress (warming-up of plants) and by adding heavy metals (for example Cd) in salt solutions (Fig 6,7). We suppose, that an extension of researches in this direction will allow promoting these ideas and approaches to the most various experimental models. Study of an action of the physical, chemical and biological factors on biota radiocapacity parameters and comparison of the level of changes of radiocapacity through external gamma-irradiation will allow to introduce an independent method of ecological dosimetry of the indicated factors., Application of similar simple model objects will presumably allow to substantiate and to concretise the given assumption.

The quantitative equivalents of dose loads on ecosystems for different factors can be found by constructing by means of model objects the relation between the change of the radiocapacity factors at a gamma-irradiation and the one of other harmful factors.

Such researches will allow shifting from a dead point a problem of the quantitative description of ecosystems and “dosimetry” of various effects on them.

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6.Conclusions

1.This theory of radiocapacity of ecosystems permits description of regularities of radionuclides distribution for different types of aquatic and terrestrial ecosystems (9,10).

2.The scale of dose commitment on ecosystems permits evaluation of the maximum permissible concentrations of radionuclides. The higher these concentrations

rise, the more noticeable influence is expected on structure, on biological characteristics and on radiocapacity parameters.

3. Regularities of radionuclide redistributions in different types of ecosystems, which are described by radiocapacity models, permit the definition of maximum permissible releases of radionuclides in particular “compartments” of ecosystems on the basis of ecological standardization.

4 In selected ecosystems (e.g. pond, water-cooling pond, forest) general ecological maximum permissible releases of radionuclides into the ecosystem or its components are determined:

a)by initial radionuclide contamination of the ecosystem and its elements;

b)by dynamics of redistribution of radionuclides;

c)by radiocapacity parameters of the ecosystems.

5.The proposed method of assessment of ecological maximum permissible radionuclide contamination of ecosystems and their components may be used as a theoretical basis for the System of Ecological Standardization of radionuclide releases from NPPs in normal and accidental conditions.

6.It was shown, that in conditions of noticeable effects at a physiological level on ecosystem by factors such as stress, suppression and/or depressing of one species, a predictable decline of ecosystem and changes in the values of the radiocapacity factors and radiocapacity of ecosystem as a whole are necessarily to be expected.

7.The following remarks are to made though: . There are the essential

concentrations of radionuclides in biota and in bottom sediments (roughly 3.7*105 Bq l-1) in the ecosystems of 10-km zone of the Chernobyl Nuclear Power Plant (NPP). Presented here are all sorts of stress-effects (chemical, biological and other nature), capable to provoking releases of radionuclides in environment (in a water, for example). Then the biota radiocapacity of the ecosystem (one or several species) will sharply decrease. It will cause in turn an increase of the content of radionuclides in water, bottom sediments and in biomass of other species of biota. Such a process is capable to continue, down to full ecosystem destruction (the lake Karachay in the Ural is an example) .

8.Thus, any effect on ecosystems affecting Tfi and Pi and other indexes of an ecosystem condition can be reflected as a noticeable change (decreasing or possibly increasing) of Fi (radiocapacity factor) and of the value of radiocapacity. Such a situation will be reflected in a reduction of permissible releases in ecosystem, for example, in the reservoir-cooler of NPP. In this case the initial well-being in ecosystem will be quickly lost. In other words the strategy directed on preservation and/or increase the radiocapacity of ecosystem and the radiocapacity factors of composed biota species of ecosystem is an optimum method of ecological-ethical management of the ecosystems.

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9.Thus well-being and viability of ecosystem bear witness of its high radiocapacity. To the contrary, high radiocapacity, and stable high values of the radiocapacity factors of ecosystem biota species bear witness of the well-being and reliability of ecosystem.

10.The control of radiocapacity and the radiocapacity factors and especially of their time changes and after-effects ( gamma-radiation , hard metals –Cd) can serve as an objective predicting criterion and method of an assessment of the well-being any ecosystems (water, continental, wood and marine ecosystems).

11.The presented method of application of tracers can be successfully applied for research and characterisation of the status and well-being of ecosystems. There are some Chernobyl’s tracers to be assumed in an ecosystem. The artificial introduction in natural ecosystem of the radionuclides 134Cs, 137Cs for example can also take place. The condition of the radiocapacity factors in the ecosystems can be assessed by estimating their dynamics over years and seasons. If after various antropogenic actions and

possible decrease of ecosystem viability, and of the decrease of its radiocapacity.

12.If the observation with tracers shows stability and especially increase of the radiocapacity factors of biota species, we the general well-being of ecosystem may be considered not to be uncertain, although some changes can certainly take place, especially in case of the use of countermeasures. At the same time the steady decrease in the value of the radiocapacity factor of one species only, not been compensated by the increase of the radiocapacity factors of other species, can be an sign of danger for a species and ecosystem as a whole. It is essential that the similar decrease of Fi (radiocapacity factors) has a predicting character. It is important, that there is possibility to carry out similar experiments in nature.

7. References

1.Agre A.L.and Korogodin V.I. (1960). About Distribution of Radioactive Pollutions in Non-flowing Reservoir. Med. Radiology, N1, p.67-73 (in Russian).

2.Polikarpov G.G. (1964). Radioecology of Marine Organisms. Moscow, Atomisdat, 296 p. (in Russian).

3.Antropogenic Radionuclides Anomaly and Plants (1991). Kiev, Lebid, 160 p.(in Russian).

4.Kutlakhmedov Y., Polikarpov G, and Kutlakhmedova-Vyshnyakova (1997): Radiocapacity of Different types of Natural Ecosystems and Ecological Standartization Principles// J. Radioecology.- V.6(2),p/1521

5.Polikarpov G.G. and Tsytsugina V.C. (1995): After Effects of Kyshtym and Chernobyl Accidents on Hydrobionts, Radiation Biology. Radioecology., Vol.35 N4: 536-548 (in Russian).

6.Amiro B.D. (1992): Radiological Dose Conversion Factors for Generic Non-human Biota. Used for Screening Potential Ecological Impacts, J. Environ. Radioactivity Vol.35, N1, : 37-51.

7.Radioactive and Chemical Pollution of Dnieper and it Reservoirs after Chernobyl Accident (1992): Kiev, Naukova Dumka, 195 p.

8.Kutlakhmedov Y.A., Polikarpov G.G. and Korogodin V.I. (1988): Principles and Methods of Ecosystems Radiocapacity Estimation. In: D.Grodsinsky (Ed.) Heuristic of radiobiology. Kiev, Naukova dumka: pp. 60-66. (in Russian).

9.Kutlakhmedov Y., Korogodin V. and Kutlakhmedova-Vyshnyakova (1997): Radiocapacity of Ecosystems, J. Radioecology, V5(1) 1997 pp.25-35.

10.Kutlakhmedov Y.A. and Korogodin V.I. (2002): Bases of Radioecology, Kiev, High school, 420 p, (in press).

THE PRINCIPAL APPROACHES TO STANDARDIZATION OF TECHNOGENIC CONTAMINATION OF ENVIRONMENT

G. PEREPELYATNIKOV

Ukrainian Radiological Training Centre,

Mashinostroitelej str., 7, Chabany, Kiev prov.

UKRAINE

Ecologists and hygienists elaborated a lot of approaches to the standardisation of technogenic pollutants founded on various principles. For standards elaboration several characteristics such as the state of soil kenosis and biochemical characteristics of soil [1], or phytotoxicity of pollutants taking into account the of metabolite ion stability constant [2], or buffer capacity of soil and its capacity of auto-cleaning. Sometimes, crops yield quality and its losses due to pollutant action or intensity of migration through food chains is taken into account as a base. No single approach exists to toxicant speciation in soil and their synergetic actions .

Integrated principles of technogenic pollutants standardisation are absent nowadays. Almost all methods of toxic substances (pollutants) content standardisation in the environment and foodstuffs can be divided into medical, hygienic, landscape, biotic and soil ones. A common methodology or approaches to ecological standardisation are not found.

This methodology elaboration is especially important for such technogenic pollutants as heavy metals, their geochemistry being bound to anthropogenic activity. The trouble with elaboration of common methodological approaches exist in the large differences between properties of various systems to be standardised. For example, water and air are considered as relatively homogeneous system, and soil is a heterogeneous one.

As soil is a basic natural factor to supply the population of the Earth with food practically to the full extent, the importance of elaboration of technogenic pollutant norms for soils becomes exactly clear. A range of principal approaches to elaboration of such norms was proposed [3, 4, 5, 6].

Firstly, the presence of in safe amounts Heavy metals in soil in addition to the natural ones should be taken as a fact. In other words the fact of impossibility of soil restoration into its original state has to accepted.

Secondly, the level of soil contamination can be used as a criterion when the natural soil properties are damaged or changed significantly. Both quantitative and qualitative changes of natural soil functions should be used for standardisation.

standardisation. Soil-and-ecological approach to heavy metals standardisation in soil is based on the prevailing features of conserving soil properties, or at least to achieving of a high quality production (good for consumption) [7].

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The principal object of ecological standardisation is the limitation of harmful actions of technogenic pollutants on biosphere and humanity by introducing of elaborated standards of their presence in the biogeosphere or trophic human chains.

To achieve the object the following tasks should be set on:

-groups of specialists in principal directions of standardisation should be formed;

terms and definitions of standardisation should be harmonised;

-or integrated principles and directions of standardisation should be defined, range of tasks should be outlined;

-methodological approaches to standardisation should be harmonised as far as possible;

-a system of standard actions should be elaborated.

On the basis of the experience gained during the elimination of the consequences of Chernobyl catastrophe, several conclusions can be drawn and used for the creation of methodological approaches to the standardisation of technogenic pollutants in naturaland agrocenoses in the area of standardisation of radioactive pollutants.

Firstly, naturaland agrocenoses include critical landscapes or links of migration chains, which accumulate small quantities of technogenic pollutants in special conditions everywhere. For instance, herbage of wet meadows subjected to radioactive contamination is characterised by high specific content of 137Cs everywhere.

Secondly, during elaboration of standards of technogenic contamination, a value of critical link or critical landscape contamination can be bound to the final standard of critical foodstuff or critical animal fodder contamination by a direct proportional dependency. Principle of soil contamination standardisation by meat as a critical product can be considered as an example (fig.1).

Fig. 1. Principle scheme of 137Cs standardisation in soil.

Meat and milk with a radionuclides content within PL-97 (no more then 200 Bq/kg and 100 Bq/l, respectively) are allowed to be collected from peat wet soil (TF for grasses is equal 10) with density of 137Cs contamination 10 kBq/m2 when the above mentioned scheme of standardisation is used. This standard of a critical link contamination can be established when contamination of a final product is getting

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below the hygienic standard. A control of other links of the migration chain is no longer relevant.

Concrete critical links should be found for resolving of standardisation tasks and for defining their area of application. For example, critical links defining radioactive contamination of agricultural production can be found in agricultural ecosystems (fig. 2).

The basic methodological approaches to ecological standardisation can be brought to consequent performing of some necessary works and fulfilling some conditions.

At the beginning of the elaboration of standards, boundaries of homogeneous equilibrium critical biogeocenoses (ecosystems) as geochemical provinces, regions, zones etc. should be defined because correct application of any standard is possible for homogeneous systems only. Ranging of landscapes and biocenosis by criticacy should be carried out within homogeneous equilibrium critical biogeocenoses. That allows to guaranteeing the standard holding in chains of biogeocenoses in case of standard elaboration for a critical chain.

Standardisation should be performed for various pollutants or their groups independently but taking into account their synergism. It seems useful to find a critical indicative pollutant for separate migration links of trophic chain. In any case pollutants have to be ranged by danger or criticacy.

During elaboration of standards, creation of block-schemes describing pollutants migration through trophic chains of man with accounting of migration links as complete as possible is an important task.

Estimation of migration fluxes of pollutants in links of man trophic chains is an important task also. Comparative analysis of pollutant fluxes in links of human trophic chains would allow distinguishing critical links and ranging them by importance and danger extent.

One of the standardisation tasks is the calculation and prediction of the relative value for maximum introduction of a pollutant into the human organism from critical link (links) of a trophic chain. Quantitative estimation of the) influence of a link (links on pollutant entering into the human organism would allow to reduce expenses to their control and make it more efficient.

Real and predicted values of a pollutant coming in into the human body from a critical link (links) of the trophic chain should be compared with sanitary-and-hygienic standards or limited permissible entering, when a harmful action of pollutants on human or biota is not defined. Such a comparison allows to solve the reverse task of pollutant standardisation in an initial link of biogeocenoses or trophic chain (detection of standardised pollutant content in a critical link of biogeocenoses or trophic chain) and establish a well justified standard.

The whole methodology for standard elaboration may be presented by the following scheme (fig.3).

ESTIMATION OF PARAMETERS OF RADIOCAPACITY OF BIOTA IN ECOSYSTEMS; CRITERIA OF THEIR WELL-BEING

Yu. KUTLAKHMEDOV

Institute of cellular biology and genetic engineering UAAS

UKRAINE

P. BALAN

Kiev Shevchenko National University, Vladymyrskaya str, 60, Kiev, UKRAINE

1. Abstract

The history of the Chernobyl accidents knows many examples, where the behaviour radionuclides in ecosystems in an obvious way reflected the course and laws of ecological phenomena, this is for example this phenomenon of active washout of nuclides from the surface of the Dnieper reservoir, in particular, from territories of Chernobyl zone of 30 km, into the territory of Ukraine and Byelorussia. Rate and parameters of such drain (0,01-2 % in year for Cs-137 and 0,1% - 4 % in year for Sr-90), define themselves as fundamental drains characteristic for big ecosystems like the Dnieper reservoir areas. The dramatic example of those phenomena of sorbptioning and desorbption of radionuclides (especially for Cs-137) in the closure of a reservoir cooler, the Kiev water basin and other superficial reservoirs, reflects the fundamental hydrological properties of water ecosystems.

The following conclusion can be drawn. At any severe hydrological, biological and technological process in ecosystems polluted by radionuclides, an appreciable redistribution of radionuclides - tracers in biotic and a-biotic components ecosystems is observed. Also the inverse conclusion is possible therefrom. Therefore it is countable count that research of distribution and redistribution radionuclides on biotic and abiotic components of ecosystems may serve as an important tool to research of dynamics and to forecasting the condition of an ecosystems and its biota.

The theory of radiocapacity of ecosystems developed hereby has permitted to assess the integrated characteristics of radionuclides distribution in ecosystems, to establish laws of radioecological processes and to determine the location of increases of radionuclides in ecosystems. The theory and models of radiocapacity of ecosystems have allowed to define approaches to a substantiation of ecological specifications on permissible levels of pollution in an ecosystem and their elements, and to permissible dumps and radionuclides emissions in ecosystems [1-3].

Our researches on reliability of ecosystems have shown a line of parameters, such as a variety of type of ecosystems; of biota; of number of species in ecosystems and rate of duplication of species. They form eventually the necessary “integrated parameter”, suitable for an estimation of the general stability and reliability of ecosystems [2, 3, 4,5].

The definition however of such parameter demands a huge amount of initial data on contributing parameters at different stages of the life of ecosystems. Already on noticeable changes of the status of the ecosystem an estimation of their well -being and reliability can be made. Clearly, when in ecosystem as a whole, the variety of

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species decreases, the biota, number and speed of duplication of dominant kinds is reduced, then it is not difficult to observe a damage and/or an oppression of ecosystems. Such affirmative research is useful, but it is not enough, as it does not allow the making of an outstripping forecast of the condition of ecosystems nor to offer counter-measures. Radiocapacity - a sensory characteristic for the plant ecosystem’s well-being is preferable. It is a non-dimensional quantity that characterises the part of radionuclides, which can be retained by the ecosystem without having deteriorated neither the whole system nor its parts. The only considerable effect on the ecosystem to be considered would the effect on the of radiocapacity rate factor. Separately, we based oneself on the theory, according to which the negative influence on the ecosystem would give rise to deterioration of its well-being; and, accordingly, - would be observe a reduction of the radiocapacity of the system. On the other hand, - the improvement of the ecosystems well-being would induce an increase of its of radiocapacity rate factor.

2. Radiocapacity as outstripping parameter of a condition ecosystems

The radiocapacity of an ecosystem is a measure of the quantity of radionuclides, which an ecosystem may contain without consequences for itself. It is obvious, that suppression and/or oppression of an ecosystem (reduction of a variety of kinds because of their destruction, reduction of a biota, number and speed of duplication) will be reflected at once in the size of the radiocapacity and of the ratio of radiocapacity factors. Radiocapacity factors determine the relative share of radionuclides in each component of a ecosystem (inert and biotic).

The hypothesis presented here is based on a large amount of empirical data, consisting of the following principles: we assume an ecosystem in steady condition contains relatively small amount long-living radionuclides (without serious impact on the condition of the ecosystem). Radionuclides are allocated to ecosystem compartments and are described by appropriate values of the factors of radiocapacity.

An external harmful factor (toxic, radiating and of any other nature) impacts on a given well-defined ecosystem. If its influence is essential it will affect the ecosystem and its parameters; ,if not essential it is not relevant to consider it,. In particular the first reaction of an ecosystem on the action of a harmful factor may be a condition of stress. Initially it will be expressed by a physiological suppression reaction and/or growth inhibition, and an outflow release of ballast substances in an environment. Then, if the action of the harmful factor proceeds and/or accrues, reductions of other parameters, down even to oppression and destruction of the most sensitive species are possibly to be expected. If this concept is true, and it is being based on a very large quantity of experimental data (on stresses in ecosystems) at stressful levels of impact on an ecosystem, when ballast substances are released in an environment, then there will be also a trace of this dump in a species in the biota that is reacting to stress to the population such that this component of ecosystem will express a sharp change of the magnitude s of radiocapacity factors.

If also o the inverse is true: if in ecosystem with known initial distribution there was an appreciable redistribution trace or traces, i.e. change of values of s of radiocapacity factors (so also the radiocapacity of the ecosystem as a whole) then an essential effect on the ecosystem has taken place. Similar events may mean, that the tested ecosystem is witnessing the influence of serious stress -, is in an unstable condition. The given concept provides an opportunity to assessing the condition of