The toxicity and concentrations of PAHs in creosote-contaminated lake sediment

Sediment samples, divided into three layers (0 - 10, 10 - 20 and 20 - 30 cm ), were collected from 16 sites in Lake Jamsanvesi, Central Finland. The ac ute toxicity of pore waters and elutriates (sediment + water 1:4 v/v) were studied by bioluminescence inhibition test and by immobilisation of water f leas (Daphnia magna Straus), Concentrations of polycyclic aromatic hydrocar bons (PAHs) in sediments and elutriates were measured by gas chromatography using flame ionization detection (GC/FID). The highest total PAH concentra tion was 3.3 mg/g dry weight in the sediment and up to 1.7 mg/l in the elut riate of the uppermost (0 10 cm) layer, also being the most toxic to photol uminencent bacteria and water flea. When sediment and water mix, like durin g dredging operations, toxic compounds may spread from the sediment to the water column and can pose on environmental risk. (C) 1998 Elsevier Science Ltd. All rights reserved.