Mining activity in Peru generates environmental liabilities with the potential to release toxic metals into the environment. This study conducted a comprehensive physical, chemical, mineralogical, and toxicological characterization of ten active and inactive tailings samples from the Arequipa region in southern Peru. Particle size distribution analysis, inductively coupled plasma atomic emission spectroscopy (ICP-AES), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and the Toxicity Characteristic Leaching Procedure (TCLP) followed by ICP-MS were employed. The results revealed variable particle size distributions, with the sample of Secocha exhibiting the finest granulometry. Chemically, 8 out of 10 samples exhibited concentrations of at least two metals surpassing the Peruvian Environmental Quality Standards (EQS) for soils with values reaching >6000 mg/kg of arsenic (Paraiso), 193.1 mg/kg of mercury (Mollehuaca), and 2309 mg/kg of zinc (Paraiso). Mineralogical analysis revealed the presence of sulfides such as arsenopyrite, cinnabar, galena, and sphalerite, along with uraninite in the Otapara sample. In the TCLP tests, 5 out of 10 samples released at least two metals exceeding the environmental standards on water quality, with concentrations up to 0.401 mg/L for mercury (Paraiso), 0.590 mg/L for lead (Paraiso), and 9.286 mg/L for zinc (Kiowa Cobre). These results demonstrate elevated levels of Potentially Toxic Elements (PTEs) in both solid and dissolved states, reflecting a critical geochemical risk in the evaluated areas.

The mining industry is a fundamental pillar of economic development in Peru, but mine tailings can generate contamination by toxic heavy metals such as Hg, As, Pb, Cd, and Zn, affecting health, flora, and fauna. This research aimed to characterize the physical, chemical, mineralogical, and toxicological properties of active and passive tailings in the Arequipa region of Peru to identify and quantify the presence of these heavy metals. Analytical techniques, such as granulometry, ICP, TCLP, SEM, and EDS were used to obtain detailed information about the characteristics of the tailings. The results showed significant variability in particle size distribution, as well as differences in mineralogical composition, including the presence of valuable and potentially toxic minerals. This study will allow corrective actions to be taken to prevent, minimize, or remediate potential negative impacts in the region.