SHORT-TERM TOXICITY OF LINDANE, HEXACHLOROBENZENE, AND COPPER-SULFATETO TUBIFICID SLUDGEWORMS (OLIGOCHAETA) IN ARTIFICIAL MEDIA

The toxicity of lindane, hexachlorobenzene, and copper sulfate to Tubi fex tubifex anti Limnodrilus hoffmeisteri was determined using an easi ly applicable and standardizable 72-h short-term test system. It was d esigned for the quick assessment of sublethal and lethal effects of se diment-associated chemicals on the worms. An artificial sediment based on the Artificial Soil according to OECD Guideline No. 207 was used a s test medium. The data confirm the common view that oligachaetes are highly tolerant of lethal effects, However, sublethal effects were det ected at considerably lower concentrations than found for lethal effec ts, The EC50 values for autotomy (172 mg/kg dry wt sediment) and sedim ent avoidance (217 mg/kg) for T. tubifex exposed to lindane-contaminat ed sediment were, for example, more than five times lower than the LC5 0 value (>1000 mg/kg), The no-observed-effect concentration for rework ing activity (8 mg/kg) was more than 125 times lower than the LC50. Tu bificids thus turned out to represent useful test organisms for the as sessment of the ecotoxicological hazard potential of chemicals in the sediment compartment, because the sublethal effects not only affect th e individual, but can influence the population levels and, consequentl y, the composition of the benthic community, (C) 1998 Academic Press.