Browsing by Author "Cabrera, Marcela"

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An integrative approach to assess the environmental impacts of gold mining contamination in the Amazon
(2021) Alvear S, Daniela ; Galarza, Emily; Capparelli, Mariana V.; Cabrera, Marcela; Rico, Andreu; Solis, Oscar Lucas; Moulatlet, Gabriel M.; Espinosa, Rodrigo; Pinos Vélez, Verónica Patricia; Perez Gonzalez, Bolivar Andres; Shiguango, Lady; Vasco, Samantha
As the number of legal and illegal gold mining sites increases in the Andes–Amazonia region, integrative methods to evaluate the effects of mining pollution on freshwater ecosystems are of paramount importance. Here, we sampled water and sediments in 11 sites potentially affected by gold mining activities in the Napo province (Ecuador). The environmental impacts were evaluated using the following lines of evidence (LOEs): water physicochemical parameters, metal exposure concentrations, macroinvertebrate community response (AAMBI), and toxicity by conducting bioassays with Lactuca sativa and Daphnia magna. Dissolved oxygen and total suspended solids were under (<80%) and above (>130 mg/Ls) quality standards 65% of the sites. Ag, Al, As, Cd, Cu, Fe, Mn, Pb, and Zn in water and V, B, and Cr in sediments were detected above quality standards at sampled sites. Nine out of eleven sites were classified as having bad environmental quality based on the AAMBI. L. sativa seed germination in both water (37% to 70%) and sediment (0% to 65%) indicate significant toxicity. In five sites, neonates of D. magna showed a 25% reduction in survival compared to the control. Our integrated LOEs index ranked sites regarding their environmental degradation. We recommend environmental impact monitoring of the mining expansion at the Andes–Amazonia region using multiple LOEs.
Human health risk assessment of metals and metalloids in mining areas of the Northeast Andean foothills of the Ecuadorian Amazon
(2022) Moulatlet, Gabriel M.; Capparelli, Mariana V.; Pérez González, Andrés; Galarza Naranjo, Emily Roxana; Pinos Vélez, Verónica Patricia; Cabrera, Marcela; Rico, Andreu
Gold mining (GM) is a major source of metals and metalloids in rivers, causing severe environmental pollution andincreasing the exposure risks to the residents of surrounding areas. Mining in Ecuadorian Amazonia has dramatically in-creased in recent years, but its impacts on Indigenous local populations that make use of rivers are still unknown. The aim ofthis study was to assess the risks to adults and children caused by the exposure to metals and metalloids in freshwaterecosystems contaminated with tailings released by GM activities in 11 sites of the upper Napo River basin, Ecuador. Weselected a carcinogenic and a noncarcinogenic risk assessment method to estimate the hazard index (HI) and total cancerrisk (TCR). The concentration of Ag, Al, As, Cd, Cu, Fe, Mn, Pb, Zn, B, and V in water and sediment samples was considered toassess the risks to human health. The calculated HI was 23–352 times greater than the acceptable limits in all sites for bothchildren and adults. Mn and Fe were the main contributors (75% in water and 99% in sediment) to the total calculated riskbased on the HI. The calculated TCR for children and adults exceeded approximately one to three times the permissiblethreshold in all sites. As and Pb contributed up to 93% of the total calculated risk based on TCR for both children and adults.This study demonstrates that the emission and mobilization of metals and metalloids caused by mining activities increase therisk to human health, to which we recommend further monitoring of freshwater contamination in the area and the im-plementation of preventive health management measures
Microplastics in rivers and coastal waters of the province of Esmeraldas, Ecuador
(2021) Capparelli, Mariana V; Molinero, Jon; Moulatlet, Gabriel M; Barrado, Miren; Prado Alcívar, Santiago; Cabrera, Marcela; Gimiliani, Giovana; Ñacato, Carolina; Pinos Vélez, Verónica Patricia; Cipriani Ávila, Eva Isabel
This study represents the first assessment of microplastic (MP) contamination in the coastal area of the Esmeraldas Province, Ecuador. MPs were quantified in 14 coastal waters in beaches with different urbanization level and in 10 rivers. The most abundant MP types were transparent fibres, brown fragments, grey fragments, transparent fragments, and black fragments, which together represented 84% of the total count. Coastal waters presented significantly higher quantities of MP than rivers. No difference in microplastic abundance was detected between beaches with higher and lower urban occupation, nor between beaches facing North or West. Our results indicate that MP contamination is widespread, and most likely transported from multiple sources. Our results can serve as a baseline for future MP monitoring in the area.