Produção Nacional
Revisado por pares
Changes in the surface water quality of a tropical watershed in the southeastern amazon due to the environmental impacts of artisanal mining
2023; Elsevier BV; Volume: 329; Linguagem: Inglês
10.1016/j.envpol.2023.121595
ISSN1873-6424
AutoresGabriel Negreiros Salomão, Roberto Dall’Agnol, Prafulla Kumar Sahoo, Gabriel Soares de Almeida, Rafael Tarantino Amarante, Leiliane Bozzi Zeferino, João Paulo Nobre Lopes, Pedro Walfir Martins e Souza Filho, Normara Yane Mar da Costa, José Tasso Felix Guimarães, Marcio Sousa da Silva, Gabriel Caixeta Martins, Mayara Fraeda Barbosa Teixeira, Eduardo Duarte Marques, Rômulo Simões Angélica, Wilker Emmanoel Oliveira Araújo,
Tópico(s)Mercury impact and mitigation studies
ResumoThe expansion of areas of human occupation and the increase in economic activity and deforestation are negatively impacting the Amazon ecosystem. Situated in the Carajás Mineral Province in the southeastern Amazon, the Itacaiúnas 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.
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