Browsing by Author "Martins, Gabriel Caixeta"

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Bioavailability of copper and nickel in naturally metal-enriched soils of Caraj�s Mining Province, Eastern Amazon, Brazil
(Springer Science and Business Media Deutschland GmbH, 2021-04-09T00:00:00) Martins, Gabriel Caixeta; da Silva Junior, Ediu Carlos; Ramos, S�lvio Junio; Maurity, Cl�vis Wagner; Sahoo, Prafulla Kumar; Dall�Agnol, Roberto; Guilherme, Luiz Roberto Guimar�es
Naturally elevated contents of copper (Cu) and nickel (Ni) are found in soils worldwide, and their potential toxicity is better understood when geochemical reactive fractions are identified and monitored. Thus, this study aimed to assess the bioavailability of Cu and Ni and estimate environmental risks in naturally metal-enriched soils of Caraj�s Mining Province, Eastern Amazon, Brazil. For that, 58 surficial soil samples were analyzed for their extractable contents of Cu and Ni by Mehlich 1. Next, 13 soil samples were selected for additional single and sequential extractions, for the determination of metal content in the shoots of grasses naturally growing in these soils and for calculating the risk assessment code. Despite the naturally high total concentrations, the contents of easily available Cu and Ni are a minor fraction of total concentrations (up to 10.15%), and the reducible oxide and residual pools hold the major proportion of total content of metals. This contributed to low bioavailability, low environmental risk, and also to low concentrations of these metals on grasses collected in the field. Soil organic matter, Fe2O3, Al2O3 and clay content have a dominant role in metals retention on studied soils. Our findings on the bioavailability of Cu and Ni in a region of great economic relevance for Brazil are important not only for predicting the elements� behavior in the soil�plant system but also for refining risk assessments and to provide useful data for environmental quality monitoring. � 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
Changes in the surface water quality of a tropical watershed in the southeastern amazon due to the environmental impacts of artisanal mining
(Elsevier Ltd, 2023-04-12T00:00:00) Salom�o, Gabriel Negreiros; Dall'Agnol, Roberto; Sahoo, Prafulla Kumar; Almeida, Gabriel Soares de; Amarante, Rafael Tarantino; Zeferino, Leiliane Bozzi; Lopes, Jo�o Paulo Nobre; Souza Filho, Pedro Walfir Martins e; Costa, Normara Yane Mar da; Guimar�es, Jos� Tasso Felix; Silva, Marcio Sousa da; Martins, Gabriel Caixeta; Teixeira, Mayara Fraeda Barbosa; Marques, Eduardo Duarte; Ang�lica, R�mulo Sim�es; Ara�jo, Wilker Emmanoel Oliveira
The expansion of areas of human occupation and the increase in economic activity and deforestation are negatively impacting the Amazon ecosystem. Situated in the Caraj�s Mineral Province in the southeastern Amazon, the Itacai�nas River Watershed (IRW) encompasses several active mines and has a historical record of intense deforestation primarily linked with the expansion of pasturelands, but also of urban areas, and mining activities. Industrial mining projects are subjected to strict environmental control, but artisanal mining (ASM; �garimpos�) sites have not been controlled, despite their known environmental impacts. In recent years, the opening and expansion of ASM in the IRW for the exploitation of mineral resources (Au, Mn, and Cu) have been remarkable. This study presents evidence of anthropogenic impacts, mainly caused by ASM, on the quality and hydrogeochemical characteristics of the IRW surface water. The hydrogeochemical data sets of two projects carried out in the IRW, during 2017 and from 2020 until present, were used to evaluate these impacts within the region. Water quality indices were calculated for the surface water samples. For the whole IRW, water collected during the dry season tended to yield better quality indicators in comparison to those collected during the rainy season. Two sampling sites at Sereno Creek showed very poor water quality and extremely high concentrations of Fe, Al, and potentially toxic elements over time. From 2016 to 2022, ASM sites increased markedly. Moreover, there are indications that Mn exploitation via ASM in Sereno hill is the main source of contamination in the area. New trends of ASM expansion were observed along the main watercourses, related to the exploitation of Au from alluvial deposits. Similar anthropogenic impacts are registered in other regions of the Amazon and environmental monitoring should be encouraged to assess the chemical safety of strategic areas. � 2023 Elsevier Ltd
Occurrence, distribution, and environmental risk assessment of heavy metals in the vicinity of Fe-ore mines: a global overview
(Taylor and Francis Ltd., 2021-06-08T00:00:00) Sahoo, Prafulla Kumar; Powell, Mike A.; Martins, Gabriel Caixeta; Dall'Agnol, Roberto; Salom�o, Gabriel Negreiros; Mittal, Sunil; Pontes, Paulo R�genes Monteiro; Guimar�es, Jos� Tasso Felix; de Siqueira, Jose Oswaldo
Several studies have investigated the consequences of heavy metal contamination in the vicinity of individual Fe ore mines, however, at present there are no systematic studies that consider the global scenario; this work strives to begin filling that gap. This review includes data reported for metals and pH in soil, overburden, sediment, tailings, and water in the vicinity of Fe mines at sites in 19 countries over the past 15 years. Elements of concern include As, Fe, Mn, Cd, Cu, Cd, Co, Pb, Ni and Zn. Various pollution and ecological risk indices were applied to evaluate environment risks by heavy metals. � 2021 Informa UK Limited, trading as Taylor & Francis Group.
Soil-sediment linkage and trace element contamination in forested/deforested areas of the Itacai�nas River Watershed, Brazil: To what extent land-use change plays a role?
(Elsevier B.V., 2022-03-08T00:00:00) Dall'Agnol, Roberto; Sahoo, Prafulla Kumar; Salom�o, Gabriel Negreiros; de Ara�jo, Alessandra Danieli Miranda; da Silva, Marcio Sousa; Powell, Mike A.; Junior, Jair Ferreira; Ramos, Silvio Junio; Martins, Gabriel Caixeta; da Costa, Marlene Furtado; Guilherme, Luiz Roberto Guimar�es
Trace elements (TE) contamination in forested areas of the Itacai�nas River Watershed (IRW), Brazilian Amazon, arouses growing interest owing to the rapid deforestation and mining activities. In this study, soils (surface, SS; bottom, BS) and stream sediments (SD) from forested/deforested areas of IRW were analyzed with the aim of (1) evaluating the major sources of TE (mainly As, Ba, Cd, Cu, Co, Cr, Hg, Mo, Mn, Ni, Pb, V, and Zn), and (2) examining the soil-sediment TE link related to land-use change and/or geologic factors. Compositional data analysis (CoDA) was used to eliminate data closure issues and the centred log-ratio (clr) transformation yielded better results in Principal Component Analysis (PCA). The TE distribution pattern was significantly different (p < 0.05) between forested and deforested areas, but in both areas the TE distribution pattern is significantly correlated between SS, BS, and SD, indicating a strong lithogenic control. PCA (clr-transformed) identified the major geochemical bedrock signature as Fe-Ti-V-Cu-Cr-Ni, which is nearly similar in soil and sediments. The more accentuated enrichment and the maximum number of anomalies of these elements were found in the Caraj�s Basin and are highly coincident with mineral deposits/local lithologies without clear indication of anthropogenic contamination from point sources. Besides geogenic factors, deforestation is also affecting TE distribution in the basin. In deforested areas, Mn was significantly enriched in the surface horizon. Furthermore, linear regression analysis shows stronger TE relationships between soils and sediments in deforested areas than in forested ones, reflecting higher erosion in the former. This could be the reason for the relatively higher enrichment of TE (e.g., Fe, Mn, Cu, Cr, Ni) in deforested sediments. The TE contamination using regional background values provides more accurate results than worldwide reference values. Thus, the former should be considered for a more realistic environmental risk assessment in IRW and other forest ecosystems in the Brazilian Amazon. � 2022 Elsevier B.V.