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(W/MF171) Biotransformation, genotoxic and histopathological effects of pulp mill effluent in European eel (Anguilla anguilla L.) . Pacheco, M.1, Santos, M.1, 1 ABSTRACT- A prolonged toxicity study was carried out in young European eel (Anguilla anguilla L.) in order to evaluate the effects of a bleached kraft pulp mill effluent (BKPME). Fish were exposed to BKPME (3.12, 6.25, and 12.5% - v/v) for 3, 7 and 30 days. The biomarkers performed include biotransformation and genotoxicity indicators, such as total ethoxyresorufin O-deethylase (EROD) activity and erythrocytic nuclear abnormalities (ENA) frequency, respectively. Haematological dynamics was assessed as immature erythrocytes (IE) frequency. Histopathological examinations (liver, spleen, kidney, gills and skin) were carried out for 30-day exposure to the highest concentration. Total EROD activity and IE frequency were not significantly affected. A significant ENA induction was observed after 7-day exposure to 3.12% BKPME. Nevertheless, the ENA results suggest impairment on the genotoxicity expression, which arise either after a long-term exposure or after a short-term exposure to high contaminant levels. Histopathological liver alterations were detected as increased density of pigmented macrophage aggregates and loss of parenchymal cells. Dispersed necrosis and focal inflammation were also observed. Exposed fish also exhibited skin and gill disruption, kidney Malpighian corpuscle alterations, as well as intense spleen hemosiderosis, indicating an increased erythrophagia. This splenic effect may be strongly correlated to the observed ENA disappearance after 30-day exposures. Neoplastic lesions were not found. A multi-biomarker strategy contributed to a better understanding of the causal relationship between contaminant exposure and biological responses. Key words: Anguilla, EROD, genotoxicity, histopathology |
