Mercury, silver, selenium and other trace elements in three cyprinid fish species from the Vaal Dam, South Africa, including implications for fish consumers.
Sci Total Environ
; 659: 1158-1167, 2019 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-31096329
ABSTRACT
The levels of Cr, Cu, Zn, Se, Ag, Cd, Hg, and Pb were determined in muscle and liver samples from 30 specimens of fish belonging to the species Labeobarbus aeneus, Labeobarbus kimberleyensis, and Labeo umbratus from the Vaal Dam. Health risks for human fish consumers were estimated using the target hazard quotient (THQ), the SeHg-ratio, and Se health benefit value (Se HBV). This is the first comprehensive report on Hg levels in fish from this lake. Mean concentrations ranging from 0.247-0.481â¯mg/kg dw in muscle and from 0.170-0.363â¯mg/kg dw in liver clearly show a contamination with this element. Although levels in muscle did not exceed maximum allowances for human consumption, a calculated THQ of 0.12 and 0.14 for the two Labeobarbus species, respectively, showed a potential risk due to additive effects. All SeHg-ratios as well as Se HBVs clearly suggested positive effects for fish consumers. Levels of Cu were remarkably high in the liver of L. umbratus, calling for further investigation on this species. Cadmium levels were above the maximum allowances for fish consumption in the liver of all three species (means between 0.190 and 0.460â¯mg/kg dw), but below the LOD in all muscle and intestine samples. This is also the first report of Ag in fish from South Africa. Levels were below the LOD in muscle, but well detectable in liver; they varied significantly between the two Labeobarbus species (0.054⯱â¯0.030 and 0.037⯱â¯0.016â¯mg/kg dw) compared to L. umbratus (1.92⯱â¯0.83â¯mg/kg dw) and showed a positive correlation with Cu levels (63.7⯱â¯17.0; 70.3⯱â¯9.0 and 1300⯱â¯823â¯mg/kg dw), possibly due to similar chemical affinities to metallothioneins. The detected Ag levels can serve as a basis to monitor the development of this new pollutant in aquatic environments in South Africa and worldwide.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Oligoelementos
/
Poluentes Químicos da Água
/
Cyprinidae
/
Monitoramento Ambiental
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article