title: A practical and user-friendly toxicity classification system with microbiotests for natural waters and wastewaters.
abstract: Various types of toxicity classification systems have been elaborated by scientists in different countries, with the aim of attributing a hazard score to polluted environments or toxic wastewaters or of ranking them in accordance with increasing levels of toxicity. All these systems are based on batteries of standard acute toxicity tests (several of them including chronic assays as well) and are therefore dependent on the culturing and maintenance of live stocks of test organisms. Most systems require performance of the bioassays on dilution series of the original samples, for subsequent calculation of L(E)C50 or threshold toxicity values. Given the complexity and costs of these toxicity measurements, they can only be applied in well-equipped and highly specialized laboratories, and none of the classification methods so far has found general acceptance at the international level. The development of microbiotests that are independent of continuous culturing of live organisms has stimulated international collaboration. Coordinated at Ghent University, Belgium, collaboration by research groups from 10 countries in central and eastern Europe resulted in an alternative toxicity classification system that was easier to apply and substantially more cost effective than any of the earlier methods. This new system was developed and applied in the framework of a cooperation agreement between the Flemish community in Belgium and central and eastern Europe. The toxicity classification system is based on a battery of (culture-independent) microbiotests and is particularly suited for routine monitoring. It indeed only requires testing on undiluted samples of natural waters or wastewaters discharged into the aquatic environment, except for wastewaters that demonstrate more than 50% effect. The scoring system ranks the waters or wastewaters in 5 classes of increasing hazard/toxicity, with calculation of a weight factor for the concerned hazard/toxicity class. The new classification system was applied during 2000 by the participating laboratories on samples of river water, groundwaters, drinking waters, mine waters, sediment pore waters, industrial effluents, soil leachates, and waste dump leachates and was found to be easy to apply and reliable.
authors: Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, J. Plateaustraat 22, 9000 Ghent, Belgium. guido.persoone@Ugent.be
authors: Guido
authors: G
authors: Persoone
authors: Blahoslav
authors: B
authors: Marsalek
authors: Irina
authors: I
authors: Blinova
authors: Andrea
authors: A
authors: Törökne
authors: Dzidra
authors: D
authors: Zarina
authors: Levonas
authors: L
authors: Manusadzianas
authors: Grzegorz
authors: G
authors: Nalecz-Jawecki
authors: Lucica
authors: L
authors: Tofan
authors: Nadejda
authors: N
authors: Stepanova
authors: Livia
authors: L
authors: Tothova
authors: Boris
authors: B
authors: Kolar
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods* / Q000592:standards*; D004784:Environmental Monitoring / Q000379:methods*; D005060:Europe; D007220:Industrial Waste; D007391:International Cooperation; D007928:Lethal Dose 50; D008906:Mining; D012016:Reference Values; D018570:Risk Assessment; D014865:Waste Disposal, Fluid; D014873:Water Pollutants / Q000633:toxicity*; D014881:Water Supply / Q000592:standards
chemical_list: D007220:Industrial Waste; D014873:Water Pollutants