Vízügyi Közlemények, 2001 (83. évfolyam)
3. füzet - Fleit E.-Bálint M.: A tiszai üledék és halak nehézfémtartalma a 2000. évi szennyezések után
A tiszai üledék és halak nehézfémtartalma a 2000. évi szennyezések után 371 Fleit E.: Ecotoxicological assessment of main discharges on the Kenyérmezei and Unyi Creeks. Acta Biol. Debrecina. Proc. 3 r d. Meeting of SECOTOX. 1994b. Somlvódv L„ Licskó !.. Fehér J. és Csánvi В.: A Sajó kadmiumszennyezettségének modellezése. Vízügyi közlemények LXVII. évf. 4. füzet. 1985. * * * Heavy metal content of the sediment and fish, after the pollution accidents of the year 2000 by Dr. Ernő FLEIT biologist and Maria BAHNT ehem. engineer The cyanide and heavy metal containing pollution waves, which arrived to Hungary from abroad in the year 2000, caused damage of smaller or higher extent to all elements of the aquatic ecosystem of the rivers Szamos and Tisza. The extent of this damage, however, could not yet be fully identified. The need for the restoration of these devastated and/or damaged ecosystems is an urgent pressure on the economy, environmental- and nature protection. This urgency is underlined by the multipurpose utilisation (water supply, irrigation, fisheries and sport angling, recreation) of these watercourses as well as by the internationally important state of some of these impacted areas (Ramsar sites). In the light of Hungary's accession process to the European Union it should be emphasised that the Water Framework Directive requests the maintaining of these water courses in near-natural state, requesting rehabilitation wherever it is applicable. The connection of existing data bases of the fauna to the data of heavy metal pollution levels of the sediment (the results of the sediment investigations made in connection to the cyanide and heavy metal pollution accidents) is a prerequisite of developing catchment basin scale rehabilitation programmes. The measurement of heavy metals in the elements of the vertebrate and invertebrate fauna and the ecological evaluation of the respective data also belong to these prerequisites. The measurement of the bioaccumulation of heavy metals in the endangered species is especially important for those species, which can be good indicators of the spreading of the heavy metals in the environment and of the ecological risk involved. Evaluating the results of the channel-bed (sediment) samples it may be stated, that the cyanide and heavy metal pollution incidents along with smaller accidents of the past had a well perceivable impact on the river reaches concerned. We have identified several toxic, carcinogen and teratogen heavy metals, which can cause, on the long term, serious public health and ecological/hydrobiological problems. Figure 1. shows the distribution of arsenic along the longitudinal profile of the sediment (after the cyanide pollution but before the heavy metal incident). Figure 2. summarises the results of the vertical distribution of heavy metals in the sediment of a near-border station (Tiszabecs). This figure clearly indicates the impact of the recent pollution accidents on the surface layer of the sediment, especially for copper, led and zinc. Figure 3. indicates the impact of the travel of the pollution wave and the zones of deposition in the light of the longitudinal variation of led. In the accession process of Hungary to the European Union it is our basic interest to became acquainted with the risk analysis methods of the Union and to become able to apply them for achieving the lastingly good, appropriate and excellent water quality conditions. In this context a characteristic feature of Hungary, and other countries of the Middle-European region, is that due to the delayed environmental investments (e.g. sewerage and sewage treatment) the so called traditional pollutants (COD, BOD, N and P forms) are present along with the non-traditional components (organic and inorganic micro pollutants). Due to the
