Consumption of food grown in contaminated soils may be a significant human exposure pathway to pollutants, including toxic elements. This study aimed to investigate the pollution level of trace elements in farmland soil and crops collected in orchards from Ponce Enriquez, one of the Ecuador’s most important gold mining areas. The concentration of arsenic (As), cadmium (Cd), chrome (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) was analyzed in soil and crop samples (celery, chives, corn, herbs, lettuce, turnips, green beans, cassava, and carrots). In addition, a probabilistic human health risk assessment, in terms of hazard quotients (HQ) and cancer risk (CR), was conducted to assess the potential risk related to local crop ingestion. The contents of As, Cr, Cu, and Ni in soils exceeded the Ecuadorian quality guidelines for agricultural soils. The trace elements concentration in local crops was higher than the maximum permissible levels set by the Food and Agriculture Organization of the United Nations (FAO). The HQ and CR of local crop ingestion were several orders higher than the safe exposure threshold, mainly for lettuce, chives, and turnips. Our results revealed that inhabitants of the study area are exposed to developing carcinogenic and non-carcinogenic effects due to long-term food consumption with high trace elements. This study sheds light on the need to assess further the quality of agricultural soils and crops grown in mining areas with signs of contamination to guarantee consumer food safety.

The Ecuadorian Amazon, particularly in the provinces of Sucumbíos and Orellana, has been heavily impacted by oil activity since the 1970s. In this context, this study analyzed 161 groundwater samples taken from deep domestic wells in both provinces, with the aim of determining the concentrations of total petroleum hydrocarbons (TPH) and their implication on the health of consumers. The results showed that, in Orellana, TPH concentrations ranged between 0.11 and 7.30 mg/L, while in Sucumbíos they varied between 0.13 and 7.45 mg/L. More than 95% of water samples exceeded the maximum permissible limit of 0.2 mg/L for drinking water, according to the quality criteria established by Ecuadorian regulations. These levels of contamination reflect a significant exposure of local communities to health risks. In particular, the study revealed that the consumption of groundwater with high concentrations of TPH can generate non-cancer and carcinogenic risks greater than the levels recommended by the United States Environmental Protection Agency (USEPA). This situation endangers the health of people, especially children, who are the most vulnerable. The findings of this study highlight the urgency of implementing control measures and risk management strategies to mitigate contamination in areas affected by oil activity and protect the health of communities that depend on groundwater in the Amazon region.

The Petaquilla gold mine in Panama was abruptly closed without restoring the site. The objective of this study is to assess mine soils from a geochemical perspective, identify potential contaminants, and conduct a human health risk assessment (HHRA). Soil samples were analysed to determine pH, EC, OM, texture, hydrocarbons (TPHs), enzymatic activity (DHA), and the following potentially toxic elements (PTEs): As, Ba, Cd, Cu, Hg, Sb, Pb and Zn. The Igeo, PLI and HHRA indexes were evaluated. The Igeo indicates that the processing zone has atypical values of Cu (1.47), indicating moderate pollution (1 < Igeo ≤ 2), Zn (3.80), indicating strong pollution (3 < Igeo ≤ 4), and Pb (7.62), indicating extreme pollution (Igeo > 5), with enrichment due to mining activity. The PLI map shows that the affected areas are surrounding the Molejon River (1.62) and the processing zone (1.21), which are slightly contaminated (1 ≤ PLI < 2), and one site in the processing zone with moderate to considerable contamination (PLI ≥ 3) at the warehouse (6.07). Regarding TPHs, the processing area in front of transformer (54,844.47 mg kg⁻¹) and the workshop entrance (2045.26 mg kg⁻¹) have values above industrial use (620 mg kg⁻¹) due to visible hydrocarbon spills. In terms of HHRA, the non-carcinogenic risk associated with exposure to PTEs exceeds the reference threshold for both children and adults under a residential exposure scenario, whereas the non-carcinogenic risk for TPHs remains below the acceptable limit. Regarding carcinogenic risk, exposure to Pb and As remains within acceptable limits for both receptors. With a view to restoring the mine’s soil, the processing area and the workshop entrance are the first areas that need to be addressed.