Examinando por Autor "Tames, Miriam"

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Accumulation and health risk from heavy metals in agricultural crops in the Mantaro Valley in the central Andes of Peru
(Elsevier Inc., 2026-06-27) Orellana Mendoza, Edith; Cosme de la Cruz, Roberto Carlos; Quispe Coquil, Violeta; Camel, Vladimir; Tames, Miriam; Aguilar, Javier; Ayllón, Reginaldo; Valero Maraví, Sheyla; Rojas León, Ángeles; Peñaloza, Richard
Cultivation of food crops in soils contaminated with heavy metals (HMs) can pose serious risks to human health. In this study, we evaluated HMs accumulation in soils and agricultural products (corn, broad beans, artichoke and alfalfa), the degree of soil contamination, and the associated health risks from three food crops using the Monte Carlo simulation model. The results revealed elevated concentrations of As, Cd, Cu, Pb and Zn in the soils, exceeding the maximum permissible limits established by both national and international standards. Soil contamination levels were particularly high for Cd, Pb and Zn. Ecological risk was also found to be very high for Cd, with artichoke-cultivated soils contributing most significantly to ecological risk. Alfalfa and artichoke tissues showed higher concentrations of As, Cd and Pb, whilst broad beans accumulated more Zn and Cu. Artichoke and alfalfa samples exceeded food safety limits for Pb. Artichoke, broad beans and corn are not HMs accumulators, as their accumulation factors were below 1. Non-carcinogenic health risks from broad beans consumption were close to the threshold hazard index of 1, suggesting a probability of adverse health effects due to HMs exposure. Broad beans and corn posed the highest carcinogenic risks, with unacceptable risk probabilities exceeding 55% in both children and adults. Arsenic and nickel showed the greatest contribution rates to carcinogenic risk in both groups. These findings suggest that food crops cultivated in HMs-contaminated soils present significant health risks for consumers. Therefore, it is necessary to adequately inform the population about these risks and to promote monitoring and management strategies that ensure food safety.
The distribution of cadmium in soil and cacao beans in Peru
(Elsevier, 2023-04-11) Thomas, Evert; Atkinson, Rachel; Zavaleta, Diego; Rodriguez, Carlos; Lastra Paucar, Sphyros Roomel-Luciano; Yovera, Fredy; Arango, Karina; Pezo, Abel; Aguilar Zapata, Javier Neptali; Tames, Miriam; Ramos, Ana; Cruz, Wilbert; Cosme, Roberto; Espinoza, Eduardo; Chavez, Carmen Rosa; Ladd, Brenton
Peru is the eighth largest producer of cacao beans globally, but high cadmium contents are constraining access to international markets which have set upper thresholds for permitted concentrations in chocolate and derivatives. Preliminary data have suggested that high cadmium concentrations in cacao beans are restricted to specific regions in the country, but to date no reliable maps exist of expected cadmium concentrations in soils and cacao beans. Drawing on >2000 representative samples of cacao beans and soils we developed multiple national and regional random forest models to develop predictive maps of cadmium in soil and cacao beans across the area suitable for cacao cultivation. Our model projections show that elevated concentrations of cadmium in cacao soils and beans are largely restricted to the northern parts of the country in the departments of Tumbes, Piura, Amazonas and Loreto, as well as some very localized pockets in the central departments of Huánuco and San Martin. Unsurprisingly, soil cadmium was the by far most important predictor of bean cadmium. Aside from the south-eastern to north-western spatial trend of increasing cadmium values in soils and beans, the most important predictors of both variables in nation-wide models were geology, rainfall seasonality, soil pH and rainfall. At regional level, alluvial deposits and mining operations were also associated with higher cadmium levels in cacao beans. Based on our predictive map of cadmium in cacao beans we estimate that while at a national level <20 % of cacao farming households might be impacted by the cadmium regulations, in the most affected department of Piura this could be as high as 89 %.