Scholarly record
POTENTIALLY TOXIC ELEMENTS IN AGRICULTURAL SOILS AND IRRIGATION WATER IN A MINING DISTRICT IN ECUADOR
Abstract
Mining activities can influence agricultural environments by altering potentially toxic elements (PTEs) concentrations in different environmental compartments, promoting their accumulation and generating potential exposure pathways. This study analyzed PTEs in agricultural soil and irrigation water in the Santa Rosa mining district, Ecuador. Fourteen soil samples were collected from agricultural farms, and ten water samples were obtained from a nearby canal used for crop irrigation. PTEs levels were measured by XRF in soils, while water samples were analyzed by ICP-MS and ICP-OES A comparison with the Ecuadorian Maximum Permissible Limits (MPLs) evidenced an PTEs-enrichment for As>Cr>Cu in soils, exceeding established limits by up to 342%, 136%, and 39%, respectively. However, none of the water samples exceeded the Ecuadorian MPLs. . The Geo-accumulation Index (Igeo) and the Metal Index (MI) were applied to assess the contamination status of soil and irrigation water, respectively. According to indexes, 86% of the soil samples were classified as moderately contaminated (1<Igeo<2), and 50% as moderately to highly contaminated (2<Igeo<3), mainly due to the influence of As, Cr, and Cu. In contrast, the irrigation water was classified as very pure (MI<0.3), despite being supplied by the Santa Rosa River, which is influenced by mining activities and has historically shown high PTE levels. These results suggest that irrigation water does not currently constitute a significant source of PTEs in agricultural soils. Instead, soil enrichment may be associated with local geogenic inputs and the potential influence of historical and ongoing mining activities in the study area. These results establish an initial environmental baseline for understanding the distribution of PTEs in agricultural soils of the Santa Rosa mining district.
Publication details
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