title: Ecotoxicological assessment of a dredged sediment using bioassays with three species of soil invertebrates.
abstract: The ecotoxicity of a dredged sediment from the Guanabara Bay (Rio de Janeiro, RJ, Brazil) was evaluated using reproduction tests with Eisenia andrei, Folsomia candida and Enchytraeus crypticus, and avoidance and feeding inhibition tests with Folsomia candida. The sediment was mixed with artificial soil to obtain the following doses: 1.25, 2.5, 5.0, 10.0, 20.0 and 40.0 %. Lead, nickel, chromium, copper and zinc concentrations were determined in the test mixtures. In reproduction tests, E. andrei was the most sensitive species (EC50 = 2.94 %), followed by F. candida (EC50 = 7.72 %) and E. crypticus (EC50 = 10.10 %). The percentage of initial weight of earthworms was significantly higher in all test concentrations compared to the control except at the highest one where earthworms biomass significantly decreased. No feeding inhibition of F. candida was observed for any test mixture and the number of organisms with a dark gut (the fed collembolans) generally increased with the increasing dose of sediment. Significant avoidance responses of F. candida were observed towards all test mixtures, however, the avoidance behaviour was the less sensitive endpoint after feeding inhibition. The results showed that chemical analysis is not sufficient to foresee toxic effects in terrestrial systems resulting from sediment disposal in soil if not complemented with an ecotoxicological evaluation.
authors.affiliation: UFF, Department of Environmental Geochemistry, Fluminense Federal University, Outeiro São João Baptista, s/n. Centro, Niterói, RJ, Brazil, ricardogc.geo@gmail.com.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Cesar
authors.forename: Tiago
authors.initials: T
authors.lastname: Natal-da-Luz
authors.forename: Franciane
authors.initials: F
authors.lastname: Silva
authors.forename: Edison
authors.initials: E
authors.lastname: Bidone
authors.forename: Zuleica
authors.initials: Z
authors.lastname: Castilhos
authors.forename: Helena
authors.initials: H
authors.lastname: Polivanov
authors.forename: José Paulo
authors.initials: JP
authors.lastname: Sousa
mesh_terms: D000818:Animals; D001181:Arthropods / Q000187:drug effects*; D061006:Bays; D001938:Brazil; D019015:Geologic Sediments / Q000032:analysis*; D009835:Oligochaeta / Q000187:drug effects*; D012989:Soil Pollutants / Q000633:toxicity*; D018675:Toxicity Tests / Q000379:methods*
chemical_list: D012989:Soil Pollutants