title: Assessment of domestic landfill leachate toxicity to the Asian clam Corbicula fluminea via biomarkers.
abstract: In order to evaluate the effects of domestic landfill leachate to bivalves Corbicula fluminea, clams were exposed to different leachate concentrations (v/v): 2, 3, 6 and 10 percent, corresponding to dilutions observed along a stream that receives this effluent, or only to clean water for comparisons. After 5 and 15 days of exposure the activity of the biotransformation enzymes 7-ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST), the multixenobiotic resistance mechanism (MXR) and lipid peroxidation (LPO) in gills and digestive gland and metallothionein (MT) content in gills were evaluated. Differences in biomarkers responses were observed between gills and digestive gland, except for MXR that decreased in both tissues of clams exposed to 6 percent for 5 days. EROD activity in gills was reduced in all leachate concentrations after 5 days and only in 2 percent after 15 days exposure, while an EROD increase was observed in digestive gland after 15 days exposure to 6 percent. GST activity increased only in the gills of clams exposed to 10 percent for 5 days. LPO varied between tissues and different conditions. A significant increase in LPO was observed in the gills, after 5 days exposure to 2 and 6 percent, and in digestive gland after 5 and 15 days exposure to 2 and 3 percent. MT content in the gills increased after 15 days exposure to 2 percent. In conclusion, different leachate concentrations tested here caused biochemical changes in C. fluminea, but due to the observed variability in biomarkers responses among leachate concentrations, it was difficult to determine patterns or thresholds concentrations.
authors.affiliation: Laboratório de Ecofisiologia Animal, Departamento de Ciências Fisiológicas, Universidade Estadual de Londrina, C.P. 10011, 86057-970, Londrina, Parana, Brazil.
authors.forename: Luciana F
authors.initials: LF
authors.lastname: Oliveira
authors.affiliation: Laboratório de Hidráulica e Saneamento, Departamento de Construção Civil, Universidade Estadual de Londrina, C.P. 10011, 86057-970 Londrina, Parana, Brazil.
authors.forename: Sandra M C P
authors.initials: SM
authors.lastname: Silva
authors.affiliation: Laboratório de Ecofisiologia Animal, Departamento de Ciências Fisiológicas, Universidade Estadual de Londrina, C.P. 10011, 86057-970, Londrina, Parana, Brazil. Electronic address: cbueno@uel.br.
authors.forename: Claudia B R
authors.initials: CB
authors.lastname: Martinez
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D049874:Corbicula / Q000187:drug effects*; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D004553:Electric Conductivity; D005880:Gills / Q000187:drug effects; D005982:Glutathione Transferase / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D015227:Lipid Peroxidation / Q000187:drug effects; D008668:Metallothionein / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D014874:Water Pollutants, Chemical; D008668:Metallothionein; D019363:Cytochrome P-450 CYP1A1; D005982:Glutathione Transferase
keywords: Biotransformation; Bivalve; Lipid peroxidation; MXR mechanism; Metallothionein