Behavioral changes in Gammarus pulex and its significance in the toxicity assessment of very low levels of environmental pollutants.

Phenolic compounds are an important group of contaminants in tap water (Kraybi l l 1978). To prevent water-transmittable epidemic diseases, drinking water is often chemically chlorinated, which may cause chemical chlor inat ion of these contaminants and the formation of stable and unstable chloro-derivat ives. Although industr ia l and agr icu l tura l practice appear to be major contributors of organic water contamination, we were able to draw attent ion to the importance of plant-derived phenolic compounds as an a l ternat ive source of phenolic water contamination (Borlakoglu and Kickuth 1986). Model chlor inat ion of 7 major plant-derived phenolic compounds produced > 65 stable chlorophenolic derivat ives. The formation of such a large number of chlorophenolic derivatives mirrors the synthetic complexity of water chlorination and the presence of these contaminants impose uncertain biological and ecotoxicological implicat ions. Studies on the bactericidal ac t i v i t y of the formed chlorophenolic mixtures using Eschericha col i as test species indicated a complex pattern of varying tox ic i t y with inh ib i t ion of growth estimates ranging between 156 to 1250 mg/L (Borlakoglu and Kickuth 1987).