Mercury exposure in riverside Tapajós communities in the Brazilian Amazon
Mercury contamination poses a major health threat to riverside communities in the Lower and Middle Tapajós River region. In this cross‑sectional study of 126 residents from eight communities (2021–2022), hair analyses revealed that 95% exceeded the WHO exposure limit of 2 µg/g, with some individuals reaching levels as high as 18.6 µg/g. Reported symptoms—including muscle and joint pain and reduced motor coordination—align with mercury toxicity. These findings confirm significant exposure linked to regional environmental contamination and highlight urgent needs for public policies to curb illegal activities that increase mercury release into aquatic ecosystems and threaten food security for Amazonian riverine populations.
Subject Tags
- Rivers
- Health
Abstract
Mercury (Hg) is considered one of the most dangerous toxic metals for the environment and human health. The present study aimed to investigate mercury exposure in riverside communities of the Lower and Middle Tapajós River. This is an observational, cross-sectional, descriptive, and quantitative study, including 126 individuals from eight communities, carried out between 2021 and 2022. A questionnaire was administered, and hair samples were collected to measure total Hg levels. Results showed that Hg levels exceeded the World Health Organization (WHO) recommended exposure limit of 2 µg/g in all the communities, and in 95% of the participants. The highest levels of Hg were observed in two individuals from the São Luís do Tapajós community (18.60 µg/g). In relation to the symptoms reported, “muscle and joint pain” was mentioned by participants from all the communities and “decreased motor coordination” in four of the communities visited. These results indicate that participants from communities in the study region are exposed to Hg and the levels observed are sufficient to trigger the reported symptoms. Results from this study can influence public policies aimed at curbing illegal activities that increase Hg contamination of aquatic ecosystems and aquatic biota, including key species for the food security of riverine populations in the Amazon region.
Citation
Rego, R. V., de Holanda, A. S. S., de Medeiros Soares, J., de Sousa Farias, M. P., Garcia, E., & do Nascimento de Moura Meneses, H. (2025). Mercury Exposure in Riverside Tapajós Communities in the Brazilian Amazon. In Amazon 2030-Sustainability Issues in the World's Largest Rainforest Region (pp. 77-92). Cham: Springer Nature Switzerland. https://doi.org/10.1007/978-3-031-81465-5_6
TNC Authors
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Edenise Garcia
The Nature Conservancy