title: Physiological effects in fish exposed to effluents from mills with six different bleaching processes.
abstract: Immature rainbow trout (Salmo gairdneri R.) were continuously exposed in a flow-through system to a total of six different bleached kraft mill effluents (BKME) at two exposure concentrations (400 and 2000 times dilution) for 7 weeks, during three consecutive years (1982-1984). The fish were exposed in outdoor tanks connected to the outgoing water from a parallel mesocosms study simulating the Baltic littoral (Fucus vesiculosus) zone. After exposure, hematological, osmoregulational) and mixed function oxidase (MFO) parameters were studied. The results showed that conventional choline bleaching (C95 + D5)EHDED, with and without treatment in aerated lagoons, had the strongest effects on the fish exposed. Oxygen prebleaching followed by high (50%) substitution of the active chlorine as chlorine dioxide, as well as oxygen prebleaching and normal (85%) chlorine levels in the CD step and treatment in aerated lagoons, had the fewest effects on the fish. The results imply a complex pattern of effects where the relative prevalence of MFO-stimulating and -inhibiting substances may give different biological results in fish exposed to these kinds of effluents.
authors.affiliation: Finnish Environmental Research Group, Vanda, Filand.
authors.forename: K J
authors.initials: KJ
authors.lastname: Lehtinen
authors.forename: A
authors.initials: A
authors.lastname: Kierkegaard
authors.forename: E
authors.initials: E
authors.lastname: Jakobsson
authors.forename: A
authors.initials: A
authors.lastname: Wändell
mesh_terms: D000818:Animals; D001772:Blood Cell Count / Q000662:veterinary; D002713:Chlorine; D019363:Cytochrome P-450 CYP1A1; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D007220:Industrial Waste; D010088:Oxidoreductases / Q000378:metabolism; D010100:Oxygen; D012487:Salmonidae / Q000502:physiology*; D012722:Sewage; D014337:Trout / Q000097:blood / Q000502:physiology*; D014865:Waste Disposal, Fluid; D014882:Water-Electrolyte Balance / Q000502:physiology
chemical_list: D007220:Industrial Waste; D012722:Sewage; D002713:Chlorine; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D019363:Cytochrome P-450 CYP1A1; D010100:Oxygen