title: Arsenic toxicity to cladocerans isolated and associated with iron: implications for aquatic environments.
abstract: Arsenic is an ametal ubiquitous in nature and known by its high toxicity. Many studies have tried to elucidate the arsenic metabolism in the cell and its impact to plants, animals and human health. In aqueous phase, inorganic arsenic is more common and its oxidation state (As III and As V) depends on physical and chemical environmental conditions. The aim of this study was to evaluate toxicity of arsenic to Daphnia similis and Ceriodaphnia silvestrii, isolated and associated with iron. The results showed differences in toxicity of As III and As V to both species. Effective concentration (EC50) mean values were 0.45 mg L-1 (As III) and 0.54 mg L-1 (As V) for D. similis, and 0.44 mg L-1 (As III) and 0.69 mg L-1 (As V) for C. silvestrii. However, As V IC25 mean value was 0.59 mg L-1, indicating that C. silvestrii has mechanisms to reduce arsenic toxicity. On the other hand, when associated with iron at 0.02 and 2.00 mg L-1, EC50 values decreased for D. similis (0.34 and 0.38 mg L-1) as well as C. silvestrii (0.37 and 0.37 mg L-1), showing synergistic effect of these substances.
authors.affiliation: Departamento de Zootecnia, Escola de Veterinária, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brasil, Universidade Federal de Minas Gerais, Departamento de Zootecnia, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte MG , Brazil.
authors.forename: Suellen C M
authors.initials: SC
authors.lastname: Sales
authors.affiliation: Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brasil, Universidade Federal de Minas Gerais, Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte MG , Brazil.
authors.forename: Arnola C
authors.initials: AC
authors.lastname: Rietzler
authors.affiliation: Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brasil, Universidade Federal de Minas Gerais, Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte MG , Brazil.
authors.forename: Marcela M
authors.initials: MM
authors.lastname: Ribeiro
mesh_terms: D000818:Animals; D001149:Arsenates / Q000633:toxicity*; D001151:Arsenic / Q000633:toxicity; D018053:Arsenites / Q000633:toxicity*; D033361:Cladocera / Q000187:drug effects*; D003621:Daphnia / Q000187:drug effects*; D007501:Iron; D023382:Toxicity Tests, Acute; D036401:Toxicity Tests, Chronic
chemical_list: D001149:Arsenates; D018053:Arsenites; D007501:Iron; C015001:arsenite; D001151:Arsenic