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da Silva HAM, Kasper D, Marshall BG, Veiga MM, Guimaraes JRD. Acute ecotoxicological effects of Hg(CN) 2 in Danio rerio (zebrafish). ECOTOXICOLOGY (LONDON, ENGLAND) 2023; 32:429-437. [PMID: 37055677 DOI: 10.1007/s10646-023-02651-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/29/2023] [Indexed: 05/22/2023]
Abstract
Artisanal and small-scale gold mining (ASGM) is the largest source of anthropogenic Hg emissions on the planet. In addition, Hg-contaminated tailings are often reprocessed with sodium cyanide (NaCN) to extract the residual gold remaining in the material. This leads to the formation of mercury cyanide (Hg(CN)2) complexes, which are often discharged in untreated form into local drainages, leading to large amounts of free cyanide being released. However, data on mercury-cyanide interactions are scarce. In this study, we investigated the impact of cyanide and Hg bioavailability in zebrafish when added as Hg(CN)2. Different concentrations of Hg(CN)2 and NaCN were used, leading to an LC50 of 0.53 mg.L-1 for NaCN and 0.16 mg.L-1 for Hg(CN)2. Analyzing free cyanide concentrations in aquarium water, >40% dissociation was observed for NaCN and about 5% for Hg(CN)2. The accumulation of total Hg (THg) in the brain, gills, muscle and kidney was quantified. All fish exposed to Hg(CN)2 had higher THg levels than their controls and kidney was the tissue with higher Hg(CN)2 accumulation. Histological effects on the kidney and gills of both cyanides in D. rerio tissues were investigated, suggesting renal alterations in fish exposed to Hg(CN)2 and showing hyperplasia in the gills of animals exposed to NaCN and Hg(CN)2. The results alert to the risks of the presence of these complexes in aquatic environments.
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Affiliation(s)
- Henrique Alencar Meira da Silva
- Laboratório de Traçadores em Ciências Ambientais Wolfgang Christian Pfeiffer, IBCCF, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, CEP 21941-902, Rio de Janeiro, RJ, Brazil.
| | - Daniele Kasper
- Laboratório de Traçadores em Ciências Ambientais Wolfgang Christian Pfeiffer, IBCCF, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, CEP 21941-902, Rio de Janeiro, RJ, Brazil
| | - Bruce G Marshall
- Norman B. Keevil Institute of Mining Engineering, University of British Columbia, Vancouver, BC, Canada
| | - Marcello M Veiga
- Norman B. Keevil Institute of Mining Engineering, University of British Columbia, Vancouver, BC, Canada
| | - Jean Remy Davée Guimaraes
- Laboratório de Traçadores em Ciências Ambientais Wolfgang Christian Pfeiffer, IBCCF, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, CEP 21941-902, Rio de Janeiro, RJ, Brazil
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Seney CS, Bridges CC, Aljic S, Moore ME, Orr SE, Barnes MC, Joshee L, Uchakina ON, Bellott BJ, McKallip RJ, Drace K, Veiga MM, Kiefer AM. Reaction of Cyanide with Hg0-Contaminated Gold Mining Tailings Produces Soluble Mercuric Cyanide Complexes. Chem Res Toxicol 2020; 33:2834-2844. [DOI: 10.1021/acs.chemrestox.0c00211] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Caryn S. Seney
- Department of Chemistry, Mercer University, Macon, Georgia 31207, United States
| | - Christy C. Bridges
- Department of Biomedical Sciences, Mercer University School of Medicine, Macon, Georgia 31207, United States
| | - Sumeja Aljic
- Department of Chemistry, Mercer University, Macon, Georgia 31207, United States
| | - Matthew E. Moore
- Department of Chemistry, Mercer University, Macon, Georgia 31207, United States
| | - Sarah E. Orr
- Department of Biomedical Sciences, Mercer University School of Medicine, Macon, Georgia 31207, United States
| | - Mary C. Barnes
- Department of Biomedical Sciences, Mercer University School of Medicine, Macon, Georgia 31207, United States
| | - Lucy Joshee
- Department of Biomedical Sciences, Mercer University School of Medicine, Macon, Georgia 31207, United States
| | - Olga N. Uchakina
- Department of Biomedical Sciences, Mercer University School of Medicine, Macon, Georgia 31207, United States
| | - Brian J. Bellott
- Department of Chemistry, Western Illinois University, Macomb, Illinois 61455, United States
| | - Robert J. McKallip
- Department of Biomedical Sciences, Mercer University School of Medicine, Macon, Georgia 31207, United States
| | - Kevin Drace
- Department of Biology, Birmingham Southern College, Birmingham, Alabama 35254, United States
| | - Marcello M. Veiga
- Norman B. Keevil Institute of Mining Engineering, University of British Columbia, Vancouver V6T 1Z4, Canada
| | - Adam M. Kiefer
- Department of Chemistry, Mercer University, Macon, Georgia 31207, United States
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