Mercury Exposure and Health Effects in Indigenous Communities of the Ecuadorian Amazon
DOI:
https://doi.org/10.67321/z8pvrm22Keywords:
mercurio, Amazonía ecuatoriana, pueblos indígenas, minería aurífera artesanal, biomonitoreo humanoAbstract
Artisanal and small-scale gold mining (ASGM), consumption of methylmercury-contaminated fish and, to a lesser extent, deforestation of geogenic mercury-rich soils and oil extraction are the main sources of mercury (Hg) exposure in the Ecuadorian Amazon. This literature review synthesizes the available scientific evidence on exposure sources, human biomonitoring levels and health effects reported in Amazonian indigenous communities, focusing on Ecuadorian territory and comparing it with Brazil, Peru, Colombia and Bolivia. A scoping narrative review was conducted in PubMed/MEDLINE, Scopus, Web of Science, SciELO and LILACS, complemented with the Consensus academic search engine, covering 2000-2026 (with emphasis on 2015-2026), from which 28 peer-reviewed studies were included. Results show that Ecuadorian evidence on environmental exposure (water, sediment, fish) is relatively recent and growing, but human biomonitoring is essentially limited to two studies more than twenty years old (hair, 2004; urine, 2016), with no recent data on hair, blood or breast milk for any of the country's indigenous nationalities. In contrast, studies from Brazil, Peru, Colombia and Bolivia consistently document hair mercury concentrations above the World Health Organization threshold (6 µg/g) in indigenous populations, associated with neurocognitive impairment, peripheral neuropathy, hypertension and impaired child neurodevelopment. We conclude that mercury exposure risk among Ecuadorian Amazonian nationalities is probably underestimated due to the absence of updated human biomonitoring, despite a documented mining boom between 2018 and 2024, and propose a research agenda focused on hair methylmercury, child neurodevelopment and epidemiological surveillance with an intercultural approach.
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