Analysis Maps Mercury Risk to 951 Amazon Communities

A new Mongabay Latam analysis reveals 951 communities across Peru, Bolivia, and Brazil are exposed or at risk from mercury contamination linked to illegal gold mining.

A new analysis indicates widespread mercury contamination affecting 951 communities across the Amazon basin in Peru, Bolivia, and Brazil. The investigation by Mongabay Latam, based on 39 scientific studies published between 1997 and 2024, maps the scale of this environmental and public health issue along 2,763 kilometers of the Madre de Dios, Beni, and Madeira rivers.

The analysis confirms that 249 Indigenous and riverside communities in these three countries have been exposed to mercury. Of these, 88%, or 220 communities, show mercury levels exceeding the limits considered safe by the World Health Organization. Additionally, another 702 communities located less than two kilometers from the analyzed rivers are considered at risk. These communities are situated between active illegal mining sites and areas already confirmed as contaminated, though no direct health assessments have been carried out for them.

Illegal gold mining is identified as the primary source of this contamination. This activity, described as violent and highly profitable, is experiencing a boom, driven by the rising price of gold, which surpassed $5,000 per ounce in January 2026. Mercury is used in the mining process to separate gold from sediment. It is then dumped into rivers, leading to irreversible contamination of water, fish, and bathing areas used by local populations.

The environmental impact of this mining is significant. In the Madre de Dios River basin alone, over 95,000 hectares of forest were destroyed between 1997 and 2024, according to the MapBiomas satellite analysis platform. Similar destruction exceeding 9,000 hectares in the Beni basin and 28,000 hectares in the Madeira basin has also occurred. Beyond forest loss, the health impact on thousands of people is a serious consequence.

Health effects on those exposed include memory loss, headaches, and damage to the central nervous system. Field reports by Mongabay Latam describe impacts on schools and breastfeeding mothers. Gladys Ordoñez, a resident of the Indigenous community of Shintuya in the Peruvian Amazon, reported that her daughter, Bayolet, had high levels of mercury in her blood at age five after fainting twice at school. Adriano Karipuna, a leader in Brazil's Karipuna territory, noted children born with heart conditions and teenagers experiencing breathing difficulties. Limberth Miquere, a community leader from Buena Vista in Bolivia, stated that residents are “tired of asking for medical assistance.”

The data reviewed by Mongabay Latam includes 7,725 mercury samples from people and 5,939 fish tissue samples. The Amazonian Scientific Innovation Center (CINCIA) supported this analysis. In Puerto Yumani, a Tacana Indigenous community in Bolivia, mercury levels were found to be nearly four times higher than the WHO threshold of 2 micrograms per gram of hair. Dora Quispe, a resident of Puerto Motor in Bolivia, highlighted the dilemma faced by many: “We are all affected by mercury. And we are this way because we eat fish. But if we stop fishing, we could starve to death; we wouldn’t have money for anything.”

For travelers and hosts considering stays in the Amazon, awareness of regional environmental challenges and supporting operations that actively work for the health of local ecosystems and communities is important.