Mercury and organic carbon distribution in six lakes from the North of Rio de Janeiro State

Sousa, Wanderson Primo de; Carvalho, Carlos Eduardo Veiga de; Carvalho, Claudia Calasans Veiga de; Suzuki, Marina Satika

doi:10.1590/s1516-89132004000100019

Cited by 16 publications

(7 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Generally, Hg and As levels in surface sediments from Mãe-Bá Lagoon (0.07-0.37 and 1.7-8.8 mg/kg, respectively) were in the same range as in other Brazilian coastal lagoons considered moderately contaminated by these metals (Lacerda and Goncalves 2001;Marins et al 1998;Mirlean et al 2003;Sousa et al 2004). On the other hand, concentrations of Zn, Cu, Ni, Cr, Cd, and Mn in the sediments from Mãe-Bá Lagoon were in the same range as those described for other Brazilian coastal lagoons considered noncontaminated by these metals (Knoppers et al 1990;Silva and Rezende 2002).…”

Section: Total Trace Metals In Sediments and Sediments Characteristicsmentioning

confidence: 53%

Effects of iron-ore mining and processing on metal bioavailability in a tropical coastal lagoon

et al. 2008

View full text Add to dashboard Cite

Background, aim, and scope In water systems, water quality and geochemical properties of sediments determine the speciation of trace metals, metal transport, and sediment-water exchange, influencing metal availability and its potential effects on biota. Studies from temperate climates have shown that iron-ore mining and tailing wastewaters, besides being a source of trace metals, usually show high levels of dissolved ions and particulate suspended matter, thus having the potential of indirectly changing metal bioavailability. For the first time in the tropics, we identified the effects of iron-ore mining and processing on metal bioavailability in a coastal lagoon. With an extensive sampling scheme, we investigated the potential sources of metals; the links among metal levels in water, sediments, and invertebrates; and the contrasting effects on metal speciation and bioavailability. Methodology The metals Fe, Mn, Al, Cr, Zn, Cu, Ni, Pb, Cd, Hg, and As were measured in water, sediments (surface and profiles), and invertebrates from Mãe-Bá Lagoon and in the sites directly influenced by the mining operations (tailing dams and nearby rivers). In addition, samples from two other lagoons, considered pristine, were analyzed. The study area is located in the southeast of Brazil (Iron Quadrangle Region and a coastal area of Espírito Santo State). General water characteristics included pH, dissolved organic carbon, alkalinity, and anion composition. Water metal speciation was assessed by a speciation model (Chemical Equilibria in Aquatic Systems). Grain-size distribution, organic carbon, carbonate, and acid volatile sulfide (AVS) were determined in sediments. Statistical methods included comparison of means by Mann-Whitney test, ordination and correlation analyses, and analysis of regression for geochemical normalization of metals with grain size. Results and discussion The dissolved metal concentrations, the total metal levels in sediments, and the normalization based on the fine sediment fraction showed that the mining operations constitute potential sources of Fe, Mn, Cr, Cu, Ni, Pb, As, and Hg to Mãe-Bá Lagoon. However, trace metal availability was reduced because of increased pH, hardness, and sulfide content (356 μmol/g) in the sites influenced by the mining. The lagoon showed similar water chemistry as in the mining sites, with metal bioavailability further decreased by the presence of dissolved organic carbon and chloride. Although AVS levels in the lagoon were low (0.48-56 μmol/g), metal bioavailability was reduced because of the presence of organic matter. Metal levels in invertebrates confirmed the predicted low metal bioavailability in Mãe-Bá Lagoon. The lagoon was considered moderately contaminated only by Hg and As. Conclusions The iron-ore mining and processing studied here constitute potential sources of metal pollution into the tropical lagoon. Contrary to expectations, however, it also J Soils Sediments

show abstract

Section: Total Trace Metals In Sediments and Sediments Characteristicsmentioning

confidence: 53%

Effects of iron-ore mining and processing on metal bioavailability in a tropical coastal lagoon

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Distribution of heavy metals in the sediments and biota of Cima Lake indicated low levels of metal pollution (Ferreira, Melo & Carvalho ; Sousa et al . ; Jesus et al . ).…”

Section: Methodsmentioning

confidence: 99%

Effects of in vitro exposure to mercury on male gonads and sperm structure of the tropical fish tuvira Gymnotus carapo (L.)

Vergilio

Moreira

Carvalho

et al. 2013

Journal of Fish Diseases

View full text Add to dashboard Cite

This study investigated the progressive effects of HgCl2 in the testis and sperm of the tropical fish tuvira Gymnotus carapo L. exposed to increasing Hg concentrations (5-30 μm) and increasing exposure times (24-96 h). Histopathology and metal concentrations in the testis were observed. Hg concentrations in the testis reached 5.1 and 5.2 μg g(-1) in fish exposed to 20 and 30 μm of Hg, respectively. Hg effects on testicular tissue were observed even at low Hg concentrations, with no alterations in gonadosomatic index. However, the quantitative analysis of the induced alterations (lesion index) demonstrated that the Hg effects in testis became more severe after exposure to higher concentrations (20 and 30 μm) and during longer exposure (72 and 96 h), probably leading to partial or total loss of the organ function. Hg exposure (20 μm) also affected sperm count and altered sperm morphology. This study showed that HgCl2 caused progressive damage to testicular tissue, reduced sperm count and altered sperm morphology. These results are important in establishing a direct correlation between Hg accumulation and severity of lesions.

show abstract

“…Atmospheric deposits also exist (Lacerda et al 2002). Together, these factors released Hg into the environment that was, and still is, available to be metabolized into methyl-Hg and incorporated into aquatic vegetation and organisms Molisani et al 1999;Yallouz et al 2001;Ferriera et al 2003;Sousa et al 2004). With the historical and ongoing sources of Hg in this ecosystem, we would expect to find elevated Hg levels in certain plants and animals, including perhaps some fish species regularly harvested and consumed by local populations.…”

Section: Study System-the Pairaba Do Sul Watershed and Inhabitantsmentioning

confidence: 99%

Mercury concentrations and awareness in Campos dos Goytacazes, Brazil: baseline measures for examining the efficacy of the Minamata Convention

et al. 2015

View full text Add to dashboard Cite

The 2013 Minamata Convention seeks to reduce anthropogenic emissions of mercury (Hg) and enhance public awareness of Hg exposure and impacts. The treaty also requires countries to increase monitoring of Hg in the environment in order to reduce human exposure and examine the efficacy of the treaty over time. Campos dos Goytacazes, Brazil, is located in a watershed with a history of significant Hg deposition from gold mining and sugarcane farming. This study provides previously unpublished data on the presence of Hg in certain fish in Campos and the awareness of mercury contamination among the local population. We analyzed Hg concentrations in five commonly consumed fish species by the residents of Campos and found concentrations to be elevated in some species, to vary significantly among species, and to correlate with trophic levels likely due to biomagnification. A sample survey of people in Campos found that education levels negatively correlated with knowledge of the presence of Hg in fish and the negative health effects of both Hg and heavy metal contamination in general. These findings have potential importance for understanding Hg levels in the environment, underscore the necessity for public awareness and education efforts regarding Hg contamination (as called for in the new Convention), and provide baseline measures for the presence of Hg in fish in Campos and public awareness related to this presence. These data can be compared to future studies to examine the efficacy of the Convention and other efforts to reduce Hg emissions and exposure to Hg in this part of Brazil.

show abstract

Mercury and organic carbon distribution in six lakes from the North of Rio de Janeiro State

Abstract: ABSTRACT

Cited by 16 publications

References 6 publications

Effects of iron-ore mining and processing on metal bioavailability in a tropical coastal lagoon

Effects of iron-ore mining and processing on metal bioavailability in a tropical coastal lagoon

Effects of in vitro exposure to mercury on male gonads and sperm structure of the tropical fish tuvira Gymnotus carapo (L.)

Mercury concentrations and awareness in Campos dos Goytacazes, Brazil: baseline measures for examining the efficacy of the Minamata Convention

Contact Info

Product

Resources

About