Effect of bleached kraft pulp mill effluent on hepatic biotransformation reactions in vendace (Coregonus albula L.)

1. The effect of bleached kraft pulp mill effluent (BKME) on xenobiotic biotransformation enzyme activities in the liver of vendace (Coregonus albula L.) was studied by exposing some fish in field laboratory tanks at 0, 0.1, 0.2 and 0.5% (v/v) effluent concentrations of BKME corresponding to 0-0.08 toxic units and others in clean water as controls. 2. Slight increase (57%, 68%) in polysubstrate monooxygenase enzyme activities, measured as benzo(a)pyrene hydroxylase and 7-ethoxycoumarin O-deethylase activities, was observed in a dose related manner after 70 days of exposure to 0.5% concentration of BKME. 3. Highest increase was observed at 0.2% effluent concentration after 120 days of exposure, measured as benzo(a)pyrene hydroxylase activity. 4. BKME had an affect on UDPglucuronosyltransferase, at the beginning (14-70 days) by decreasing and in longer exposure (120 days) by slightly increasing the activity.