Examinando por Materia "Metales pesados"

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Ecological and carcinogenic risk assessment of potentially toxic elements in rangelands and croplands around Lake Junin (Peru): Integrating remote sensing, machine learning, and land cover segmentation
(Elsevier, 2025-08-27) Pizarro Carcausto, Samuel Edwin; Requena Rojas, Edilson Jimmy; Barboza, Elgar; Peña Elme, Eunice Dorcas; Arias Arredondo, Alberto Gilmer; Ccopi Trucios, Dennis
The Junín Lake basin, a critical high-altitude ecosystem in the central Peruvian Andes, faces severe contamination from potentially toxic elements (PTEs) driven by mining activities, agriculture, and urbanization. This study evaluates the spatial distribution, ecological risk, and human health implications of 14 heavy metals, metalloids, and trace elements in surface soils surrounding the lake. Using 211 soil samples, we integrated remote sensing, land cover classification, and Random Forest machine learning models with spectral, edaphic, topographic, and proximity-based environmental covariates to predict contamination patterns and assess risk. Results reveal extreme contamination, with arsenic (As), lead (Pb), cadmium (Cd), and zinc (Zn) concentrations exceeding ecological thresholds by over 100-fold in agricultural zones. Ecological risk assessments using contamination degree (mCD), pollution load index (PLI), and risk index (RI) indicated that over 99 % of the study area exhibits very high to ultra-high contamination levels. Human health risk analysis identified unacceptable carcinogenic risks from As, Pb, and Cr across adult and pediatric populations, with arsenic presenting the greatest concern. The integration of geospatial tools and machine learning enabled precise identification of contamination hotspots and vulnerable land cover types, demonstrating the value of AI approaches for monitoring contaminated territories. These findings underscore the urgent need for coordinated environmental management, targeted remediation strategies, and community-based monitoring to protect public health and preserve Andean ecosystem integrity.
Potential of extremophilic and native microbial consortia in the bioleaching of heavy metals on mining process
(CRC Press, 2024-04-12) Hualpa Cutipa, Edwin; Solorzano Acosta, Richard Andi; Huayllacayan Mallqui, Jorge Johnny; Aguirre Catalan, Heidy Mishey; León Chacón, Andrea; Castro Tena, Lucero Katherine
Mining is a significant economic activity in many countries, resulting in the release of wastewater with high concentrations of heavy metals and other harmful compounds. Leaching is a treatment technique for these effluents, allowing the recovery of precious metals through solubilization, but it generates large amounts of tailings and waste effluents. Microbial leaching (bioleaching) is a biological strategy where microbes are used to solubilize precious metals in insoluble substrates through microbial metabolism or metabolic products. Extremophilic microorganisms, particularly those formed by indigenous consortia (bacteria and fungi), have versatile metabolic traits that are highly valued. Some heterotrophic bacteria adapt to acid environments and high concentrations of heavy metals as a defense mechanism against heavy metals. The pH is a fundamental parameter of bioleaching, and for efficient bioleaching, microbial consortia composed of mixed cultures, mainly extremophilic microbes, are proposed due to their poly-resistance to a reduced pH, likely to favor the recovery of metal. This chapter addresses the main characteristics of extremophilic microorganisms forming native microbial consortia and their biotechnological potential in the bioleaching of heavy metal-rich mining effluents. The aim is to highlight advanced strategies or methods for studying this group of microorganisms, considering their enormous potential as a priceless source of compounds of interest for various fields such as medicine, agriculture, and mining.
Soil, site, and management factors affecting cadmium concentration in cacao-growing soils
(MDPI, 2020-06-05) Scaccabarozzi, Daniela; Castillo, Luis; Aromatisi, Andrea; Milne, Lynne; Bullón Castillo, Adolfo Alejandro; Muñoz Rojas, Miriam
Soil contamination by potentially toxic trace elements (PTEs) such as Cadmium (Cd), is a major environmental concern because of its potential implications to human health. Cacao-based products have been identified as food sources with relatively high Cd contents. Here, we assessed Cd concentrations of cacao-growing soils in four major agricultural regions with contrasting climates in Peru, one of the main exporters of cacao products worldwide. At each study site (n = 40) a broad range of potential factors affecting Cd concentration in soils, i.e., site, soil and management, were evaluated. Concentrations of Cd ranged between 1.1-3.2 mg kg-1. Mean values per region were below 2.7 mg kg-1, usually established as upper-limit for non-polluted soils. Cadmium concentrations were significantly (p < 0.001) higher in sites at higher elevations and in a temperate, drier climate. Cadmium correlated positively with pH (r = 0.57; p < 0.05) and was higher (p < 0.001) in alluvial sediments and Leptosols. Management factors (cacao variety, cultivation year, management practices) and agroecology did not affect Cd concentrations directly. Overall, this study highlights the importance of considering a broad range of both natural and anthropogenic factors to evaluate Cd concentrations in cacao-growing soils and contribute to effective and sustainable cacao production by improving land management and planning