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Ecological and probabilistic human health risk assessment of heavy metal(loid)s in river sediments affected by mining activities in Ecuador

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Gold mining is a significant source of metal(loid)s released into the environment. It is an issue of concern due to the potential adverse health effects associated with exposure to toxic elements. This study aimed to assess the ecological and human health risk caused by heavy metal(loid)s exposure in river sediments in Ponce Enríquez, one of the most important mining sites in Ecuador. Concentrations of As, Cd, Cu, Pb, and Zn were evaluated in 172 sediment samples to determine the Potential ecological risk (RI) and the carcinogenic (CR) and non-carcinogenic risk (HQ). The human exposure to polluted sediments during recreational activities was computed using Bayesian probabilistic models. Residents were randomly surveyed to adjust the risk models to the specific population data. More than 68% of the sampling stations pose a severe As and Cd ecological risk index (\(E_{{\text{r}}}^{i}\) > 320). Likewise, residents exposed to river sediments showed a non-acceptable carcinogenic risk by incidental ingestion, being As the primary contributor to overall cancer in both children and adults receptors. Moreover, non-carcinogenic risk through the incidental ingestion of sediments was above the safe limit for children. This is the first study conducted in a mining region in Ecuador that reveals the severe levels of ecological and human health risk to which the population is exposed. These results can be applied as a baseline to develop public health strategies to monitor and reduce the health hazards of the residents of mining communities.

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Data availability

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.


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The authors thank Washington Pincay, Daniel Falquéz, and Martha Hidalgo for their contribution to sample collection and chemical analyses.


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Samantha Jiménez Oyola was involved in conceptualization, methodology, writing—original draft preparation. María Jesús García Martinez was involved in conceptualization, supervision, writing—reviewing and editing. Marcelo F. Ortega contributed to methodology, formal analysis, writing—reviewing and editing. Eduardo Chávez contributed to conceptualization, resources, writing—reviewing and editing. Paola Romero contributed to project administration, resources and reviewing. Iker Garcia-Garizabal was involved in writing—reviewing and editing. David Bolonio was involved in writing—reviewing and editing.

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Correspondence to María-Jesús García-Martínez.

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Jiménez-Oyola, S., García-Martínez, MJ., Ortega, M.F. et al. Ecological and probabilistic human health risk assessment of heavy metal(loid)s in river sediments affected by mining activities in Ecuador. Environ Geochem Health 43, 4459–4474 (2021).

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