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Ecotoxicological risk in the Caspian Catchment-area


Foreseen Results

Therefore an investigation of the future expected change of OH-concentration as a consequence of an increase of the UV-B-radiation is not only of high interest for basic research but also for applied research, i.e. for practical life.

It is expected that the results will also lead to recommendations for agricultural activities, for forestry and for environmental protection and preservation activities.
The Caspian Sea as the largest inland lake is a highly endangered ecosystem because it has no flow off and has a large influx of organic and inorganic anthropogenic pollutants transported into it by the rivers Wolga and Ural, by oil refineries and others industries near the sea shore. The pollutants with little volatility are transported in a fairly short time period into so called ecological sinks where they will be deposited. A large amount of the pollutants with high volatility are emitted into the atmosphere and because of the large evaporation rates of the Caspian Sea parts of it get transported to southern Europe and middle Asia.

If one assumes that the Wolga transports similar leads of pollutants as the Elbe river in the time period before 1990 - which is very plausible - then one has to expect very large amounts of VCH's (about 4000 tons 1,1,1-trichloroethane per year and about 2000 tons 1,2-dichloroethane per year) which being transported into the Caspian Sea and which will be emitted into the local troposphere. These airborne VCH's will be photochemically decomposed and the resulting substances create a significant exotoxicological risk for the environment of the Caspian Sea for example for the vegetation of the semidesert and desert regions of Middle Asiatic character and for the summer green of the north Caucasian forests. At four selected locations biomonitoring - using pine forest trees and bush vegetation - and soil analysis will be carried out in addition.

The reduction of stratospheric ozone, especially during the last five years, resulted in an increase of the UV-B-radiation that reaches the surface of the earth and this leads to a change, i.e. an increase of the OH radical concentration in the troposphere. This will very likely result in a change of the decomposition rate of the VCH's in the troposphere and to an increase of the amount of trichloroacetic acid deposited on the vegetation and on the soil. This increase will lead for parts of the vegetation to phytotoxic hypergrowthrates and/or defects of the fineroots of some plants.

Funding Scheme

CSC - Cost-sharing contracts


Permoser Strasse 15

Participants (2)

A.M. Obouhov Institute of AtmosphericPhysics - Russian Academy of Sciences
109017 Moscow
1,Halbarthgasse 1
8010 Graz