Elsevier, Ecotoxicology and Environmental Safety, 3(62), p. 427-435
DOI: 10.1016/j.ecoenv.2004.11.004
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To assess the estrogenicity of a municipal sewage treatment plant, sexually mature crucian carp of both sexes were exposed for 28 days to domestic treated sewage effluent running with a constant flow of water, with tap water and with different concentrations of the sewage effluent (25%, 50% and 100%). Vitellogenin (VTG), gonadosomatic index (GSI), hepatosomatic index (HSI), and histological abnormalities were used to assess the estrogenic potency of the effluent. Results show a significant (P<0.05) increase in VTG levels in all exposed male fish. A significant (P<0.05) reduction in the GSI was only observed in fish exposed to 100% effluent. Morphological changes were detected by histological evaluation, revealing severe effects on the testes. Spermatogenesis was progressively reduced to total inhibition in fish exposed to 100% effluent. One of the most pronounced effects detected was the presence of oocytes in male gonads, observed in 20% of males exposed to 100% sewage effluent.