Risco ambiental e à saúde humana de elementos potencialmente tóxicos em resíduos de áreas de mineração artesanal de cassiterita e monazita na Amazônia.

Abstract

Mineral exploration is essential for global economic development. In the Amazon region, artisanal mining is predominant and conducted on a large scale, with little regard for environmental impacts and human health, primarily due to the release of large amounts of potentially toxic elements (PTEs), including rare earth elements (REEs). Rare earth elements (REEs) include the lanthanide family, scandium, and yttrium, and are essential for sustaining modern technologies. In the region of São Felix do Xingu, located in the Amazonian craton, there are minerals containing rare earth elements, including monazite and cassiterite. In Chapter 1, the risk to the environment and human health was assessed in waste (overburden and tailings) from three artisanal mining areas of cassiterite and monazite, based on the length of exploitation. In Chapter 2, environmental and human health risk indices were estimated for PTEs (metals and metalloids) that showed concentrations above the quality reference values for the state of Pará. REE and PTE concentrations were quantified by alkaline fusion and ICP-MS. The results were used to calculate pollution, environmental risk, and human health indices. Waste from monazite and cassiterite mining led to increased concentrations of REEs and PTEs, with high enrichment and a high contamination factor for REEs and PTEs. Waste from active and recently deactivated mines showed high ecological risk. The results indicate that artisanal cassiterite and monazite mining has potential for PTE and REE contamination and enrichment. The significant bioaccumulation in forage plants indicates a high potential risk in a municipality that is the largest producer of cattle in the country. Therefore, regulatory and damage mitigation measures need to be considered.