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(38-21) Ecotoxicity Assessment of De-icing Chemicals. Joutti, Anneli*,1, Schultz, Eija1, Taina, Nysten1, Pasi, Helsten1, Piia, Pessala1, 1 SYKE (Finnish Environment Institute), Helsinki, Finland ABSTRACT- De-icing agents are mainly classified on their physico-chemical properties as boiling point, density and solubility in water. Contamination in the environment is evaluated by measuring the chemical concentrations of the de-icing agents in solid or water phase. However, the chemical data by themselves do not allow to evaluate toxic effects on the soil flora and fauna on groundwater quality. Biological assessment could help to define the integrated ecotoxicological effects of contaminants. There are only very few studies reported in the literature on the ecological impacts of these de-icing agents to soil flora and fauna. Risks to groundwater is considered important due to the high relative mobility of de-icing chemicals through soils. Efforts to establish criteria for de-icing chemicals in soil and groundwater are complicated by a number of variables such as: degradation, temperature, soil type and depth of contamination, altered toxicity of aged compounds and presence of co-contaminants.- In Finland, the environmental protection act forbids even endangering the quality of ground water. However, de-icing cannot be stopped completely on juridical basis and we have to find solutions to minimize the negative effects of de-icing without endangering traffic safety. The objective of this work was to get information on the effects de-icers might have on ground water and soil quality. Sodium chloride and five alternative de-icers (calcium chloride, magnesium chloride, potassium formiate, potassium acetate and CMA or calcium magnesium acetate) were studied with different aquatic bioassays. The toxicity measurement of the samples was carried out with two plants (the Allium cepa root elongation test and the Lemna minor growth inhibition test), bacteria (the luminescent bacteria Vibrio fischeri assay) and enzyme inhibition (the reverse electron transport, RET, assay). Key words: de-icing chemicals , soil toxicity, groundwater toxicity, phytotoxicity |
