Vinicius Tavares Kütter

Mercury speciation in fish of the Cabo Frio upwelling region, SE-Brazil

Mercury distribution in the oceans is controlled by complex biogeochemical cycles, resulting in retention of trace amounts of this metal in marine biota. The impact of upwelling processes in this metal behavior has been overlooked. Data from literature are insufficient to evaluate the risks associated with the presence of mercury in the fish collected in upwelling areas and its consumers. Therefore, the aim of the present work was to perform a study of mercury speciation in four fish species belonging to different trophic levels from Cabo Frio-Brazil upwelling region. The total mercury content vary of 53 ng g-1 (Sardinella brasiliensis -sardine) to 1215 ng g-1 (Cynoscion striatus -striped weakfish) and, with exception of the planktivorous fish, methylmercury levels reaches circa 90% of total mercury concentration.

Use of the digestive gland of the oyster Crassostrea rhizophorae (Guilding, 1828) as a bioindicator of Zn, Cd and Cu contamination in estuarine sediments (south-east Brazil)

This study demonstrates the accumulation of Zn, Cd and Cu in the digestive gland of the oyster Crassostrea rhizophorae in response to the contamination of sediments and discusses the potential use of this specific organ in monitoring metal contamination in tropical areas. Sediment and oyster samples were collected from coastal Rio de Janeiro sites with different levels of human impact: Sepetiba Bay, Guanabara Bay and the Paraty coast. Metal concentrations were measured using inductively coupled plasma optical emission spectrometry (ICP OES). Significant statistical differences (p<0.001; p<0.05) were observed for Zn and Cd concentrations in the digestive gland; the highest Zn concentrations were found at Sepetiba, followed by Guanabara and Paraty. The highest digestive gland Cd concentrations were found at Paraty, followed by Sepetiba and Guanabara. These concentrations were proportional to those found in the sediments. There was no significant difference (p>0.05) in Cu among the sampling sites. The highest digestive-gland Cu concentration was also found at Sepetiba, followed by Guanabara. The biosediment accumulation factor indicated a gradient of sediment contamination for Zn and Cd. The digestive gland of C. rhizophorae can be a potential indicator of trace metal contamination in sediments from tropical estuarine environments.

Vanadium-binding protein in marine plankton from tropical south atlantic ocean

We investigated the role of plankton in the vanadium (V) cycle at Cabo Frio, Rio de Janeiro state, Brazil, a region with high V concentration in the atmospheric particles due to marine aerosol. The concentrations of V in plankton vary from 0.08 to 20.9 µg g-1 (zooplankton), 0.1 to 28.4 µg g-1 (phytoplankton > 64 µm) and 20 µm). The V speciation in biomolecules was performed by the use of two strategies: (i) coupling of size exclusion chromatography (SEC) for the fractionation of species with inductively coupled plasma mass spectrometry (ICP-MS) and (ii) with size exclusion anionic exchange chromatography with UV-Vis detector coupled to inductively coupled plasma mass spectrometry (SEC-AE-UV-Vis-ICP-MS). The results showed a single fraction containing V associated with a biomolecule in the range of 8 to 16 kDa, with isoeletric points above 8. The preliminary analyses using matrix-assisted laser desorption-ionization-time of flight (MALDI-TOF) do not permit to identify such biomolecule, considering the broader size range of the proteins obtained.

First assessment of trace metal concentration in mangrove crab eggs and other tissues, SE Brazil

The mangrove crab Ucides cordatus is widespread in the Brazilian coast, which has an important role in nutrient cycling. This species reproduces in summer and females carry eggs about a month, when they maintain contact with water and sediments. It remains unclear if trace metals can be absorbed or adsorbed by the eggs during development. The present study aims to investigate, for the first time, trace metal concentrations in ovigerous female tissues and eggs of U. cordatus in two areas with different metal pollution levels in the Southeastern Brazil. Samples were collected in two different mangroves, Guanabara Bay (GB) highly polluted environment and Paraíba do Sul River (PSR). In both populations, we observed significant increase of V, Cr, and Mn concentrations along eggs maturation. The higher metals averages were found in PSR population. This trend was reported since the 1990s and lower concentrations in GB marine organisms were attributed to reducing conditions, high organic load, and the presence of sulfide ions. These conditions restrict the bioavailability of metals in the bay, with exception of Mn. No significant differences were observed in gills and muscles. In both populations of the present study, V, Zn, As, and Pb were higher in eggs of initial stage, whereas Mn, Ni, Cu, and Cd were higher in hepatopancreas. Beside this, V, Cr, Mn, As, and Pb showed an increase concerning egg development. Thus, V, As, and Pb in eggs come from two sources previous discussed: females and environment. Zinc came mainly from females due to essential function. Those new information should be considered as one of the mechanisms of trace metal transfer to the trophic chain, between benthonic and pelagic environment.

Mercury bioaccumulation in fishes of a paddy field in Southern of Brazil

Aim: The aim of present study was to evaluate the Hg concentration in two species of fish (Astyanax sp and Corydoras paleatus) and its potential use as a biomonitor, in order to know if the use of pesticides and fertilizers in paddy can enhance the Hg contamination to adjacent aquatic environment.MethodsSoil, suspended particulate matter and fish samples were sampled in a paddy field in South Brazil. A cold vapor system, coupled with a GBC 932 atomic absorption spectrophotometer was used for total Hg determinations in samples.ResultsThe paddy soil shows Hg concentration 2-fold higher (mean 31 ng g-1) in comparison to background areas (not cultivated). Suspended particle matter Hg concentration in paddy channels (mean 232.5 ± 44.2 ng g–1) are 1.5 times higher than the regional background. The analyzed fish specimens Astyanax sp in paddy showed Hg concentration 4-fold higher and significant different to background area. The mean Hg concentration in fish was: 51.7 ± 19.5 ng g–1 in Astyanax sp and 156.8 ± 44.0 ng g–1 in Corydoras paleatus.ConclusionsConsidering the linear regression and Man whitney test hypothesis to Hg concentration in fish tissue from paddy suggests that Astyanax sp. can be a good biomonitor of Hg contamination, whereas Corydoras paleatus is a potential biomonitor. However, more studies with Corydoras are necessary in order to aggregate consistency to this hypothesis.

Riscos de ingestão de flúor: estudo de caso para água mineral do interior do estado do Rio de Janeiro

O consumo de fluor presente em aguas superficiais e subterrâneas e umapratica comum em diversos paises. Alem de abordar a tematica controversaquanto ao consumo do fluor, este artigo apresenta um estudo de caso deavaliacao de risco a saude humana pelo consumo de aguas fluoretadas,provenientes do Parque de Aguas Minerais, localizado na regiao Centro-Suldo Estado do Rio de Janeiro. As concentracoes de fluor foram medidas entreoutubro de 2014 e agosto de 2015 em tres pocos de agua mineral e emseus respectivos fontanarios, sendo as fontes denominadas popularmentede Fonte Alcalina Terrosa Calcica, Alcalina Terrosa Ferruginosa e AlcalinaTerrosa Magnesiana. Foi avaliada a possibilidade de haver riscos para odesenvolvimento de fluoroses e aumento de fraturas osseas nas populacoesconsumidoras. Esta pesquisa modelou a ingestao diaria dessas aguascom fluor por receptores residenciais dos tipos: bebes, infantes, criancas,adolescentes e adultos. Foi constatado que os grupos de bebes e infantespodem estar mais sujeitos a riscos cronicos para o desenvolvimento defluorose dentaria na fonte de agua mineral Alcalina Terrosa Magnesiana.Recomenda-se que a agua mineral dessa fonte nao seja consumida pelosgrupos de criancas.

Determination of Metallothioneins and Phytochelatins using HPLC-ICPMS

Metallothioneins and phytochelatins are peptides and proteins associated with metals present in all biological systems. Generally, in the presence of certain metal concentration, they are produced naturally by the body. There are several applications including their use as indicators of environmental pollution and to fight disease. For the determination of metallothioneins and phytochelatins is necessary to use a very detailed chemical analysis procedure that involves the extraction of these complexes, followed by a methodology of separation or purification of compounds extracted and finally by the detection of both the organic compound (the protein) and the metal associated with it. Different strategies should be used whether the subject of the analysis is the apo-form of the biomolecule or the metallic complex. In the second case, special care has to be taken for preserving the metal-biomolecule association along the sample preparation procedure. UV-VIS absorbance, fluorescence or mass spectrometry are often used for detection of the biomolecules. In the case of metallic complexes, high performance liquid chromatography (HPLC High Resolution Liquid Chromatography) is the most used technique for separation, associated to mass spectrometry with inductively coupled plasma (ICP-MS Inductively Coupled Plasma Mass Spectrometry), an elemental technique, that allows the detection of metallic ions. Some aspects of this technique and its application are described in this paper.