Impact of aquatic humic substances on speciation and toxicity of arsenic and cobalt to Ceriodaphnia dubia

Autor(es)

Watanabe, Claudia Hitomi ; Gontijo, Erik Sartori Jeunon ; Domingues, Murilo Teles ; Fracacio, Renata ; Rosa, Andre Henrique

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; v. N/A, p. 8-pg., 2023-05-30.

Resumo

Humic substances (HS) interact with trace metals such as As and Co, affecting their mobility and availability in aquatic systems. However, their combined effects on toxicity to aquatic organisms are not totally understood. The objective of this study was to evaluate the toxicity of Co(II) and As(III) to the water flea Ceriodaphnia dubia in the presence of HS, considering element speciation. Toxicity assays were performed in the presence and absence of HS at two different concentrations of As(III) (10 and 20 mu g/L) and Co(II) (50 and 100 mu g/L). The free As(III) and Co(II) (< 1 kDa, fraction most potentially bioavailable) in the test solutions were determined via ultrafiltration. While free Co(II) decreased by approximately 80% in the presence of HS, free As(III) decreased just by 1%. Despite the higher percentage of As(III) potentially bioavailable, the presence of HS reduced significantly the toxicity of As at 20 mu g/L (no toxicity was observed at 10 mu g/L). This was attributed to direct effects of HS such as hormesis, hormone-like effects of HS and/or formation of protective coating. These effects also stimulated the reproduction, including in the assays in the absence of As and Co. HS reduced the toxicity of Co(II) at both test concentrations. The results of this investigation support that HS should be considered when safe limits for As and Co are defined. (AU)

• Processo FAPESP: 19/06800-5 - Poluentes orgânicos persistentes emergentes no ambiente: ênfase em retardantes de chama bromados (BFRs) e substâncias perfluoroalquílicas (PFASs)
• Beneficiário: André Henrique Rosa
• Modalidade de apoio: Bolsas no Exterior - Pesquisa
• Processo FAPESP: 13/06000-2 - Imobilização de fosfatos em microesferas poliméricas contendo biochar: preparação, caracterização e liberação lenta em sistemas aquosos
• Beneficiário: Murilo Teles Domingues
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 12/19580-4 - Avaliação ecotoxicológica de metais/metalóides e interferentes endócrinos em frações de substâncias húmicas de diferentes tamanhos moleculares
• Beneficiário: Cláudia Hitomi Watanabe
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 12/17727-8 - Distribuição, complexação e mobilidade de íons arsênio em águas superficiais do Quadrilátero Ferrífero-MG/Brasil: ênfase nas interações com substâncias húmicas aquáticas
• Beneficiário: Erik Sartori Jeunon Gontijo
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 14/20979-4 - Transporte, disponibilidade e ecotoxicologia de nanopartículas no ambiente: interações com matéria orgânica natural em sistemas aquáticos
• Beneficiário: Cláudia Hitomi Watanabe
• Modalidade de apoio: Bolsas no Brasil - Doutorado