The poisoning of Munduruku land
New evidence of widespread illegal gold mining in Indigenous territory in the Brazilian Amazon
September 21, 2026
The traditional lands of the Munduruku Indigenous people sit along Brazil’s deforestation frontier, placing them on the frontlines of the fight to save the Amazon.
Photo: Wakoborũn and Da’uk AudioVisual Collectives
Photo: Wakoborũn and Da’uk AudioVisual Collectives
Photo: EIA
Photo: EIA
Photo: EIA
Photo: EIA
Photo: Wakoborũn and Da’uk AudioVisual Collectives
Photo: Wakoborũn and Da’uk AudioVisual Collectives
Photo: Wakoborũn AudioVisual Collective
Photo: Wakoborũn AudioVisual Collective
The Munduruku have lived in the Tapajos River basin and surrounding areas for centuries.
But only in the last few decades has the Brazilian government slowly begun to formally recognize their rights to the land they have historically occupied.
Government-recognized Munduruku territories cover more than 37,500 square kilometers.
The largest contiguous block of legally-recognized Munduruku land is contained in three Indigenous Territories (ITs).
The 1,260 km² Sai Cinza IT, established in 1991
The 23,820 km² Munduruku IT, established in 2004
And the 10,500 km² Kayabi IT, established in 2013.
These territories are being invaded for illegal gold mining despite legal protections that prohibit commercial mining. Illegal mining is destroying forests and waterways across Munduruku territory, poisoning the environment with toxic mercury used during the mining process.
Mining runoff is exposing the Munduruku to dangerous levels of mercury, contaminating the water they drink and the fish that are a staple of their diet.
Annual deforestation data from Global Nature Watch shows the progression of illegal mining along rivers concentrated in the east and north of the Munduruku IT between 2014 and 2024.
After sustained advocacy by the Munduruku and their allies, the Brazilian Supreme Court and Inter-American Court of Human Rights (IACHR) have called on the government to enforce laws protecting Indigenous peoples and stop the mining invasions.
Between November 2024 and January 2025, the government carried out a major law enforcement operation against illegal gold mining in the Munduruku and Sai Cinza ITs. While the operation temporarily halted most mining, the impacts were short-lived. It soon began to ramp up again.
EIA is supporting the Munduruku’s use of technologies such as GPS, satellite imagery, and drones to monitor and document territorial invasions and provide evidence to Brazilian authorities and the IACHR.
A series of monitoring reports prepared by three Munduruku organizations - the Wakoborũn Munduruku Women's Association, the Da'uk Association and the Munduruku Ipereğ Ayũ Movement - with support from EIA prompted Brazil's Public Prosecutor’s Office (MPF) to demand explanations from government agencies tasked with protecting Indigenous territories earlier this year. To date, we are not aware of any further actions by the government to stop the illegal mining in Munduruku territory.
In light of the evidence, an IACHR delegation traveled to Brazil in early September to assess the government’s compliance with its obligations under international law to protect the rights and livelihoods of the Munduruku.
In advance of the IACHR's visit, Munduruku organizations and EIA jointly submitted new evidence to Brazilian authorities and the IACHR. The report uses high-resolution satellite imagery to document ten illegal mining sites active in 2026 in the Munduruku and Sai Cinza ITs.
Here we present four examples of new illegal mining identified in the report.
One major site was identified near the source of the Crepori River in the south of the Munduruku IT.
This is what the site looked like in October 2025 using satellite imagery.
Two months later, a nine mile road had been carved across Rio Novo National Park to an illegal mining site inside the Munduruku IT, as evident from deforestation visible in the satellite imagery.
The site had grown by March 2026, when the Munduruku and EIA first detected it and notified Brazilian authorities.
By May, the site had expanded further.
By July, more than 13 hectares of forest (an area equivalent to 18 soccer fields) had been cleared.
EIA verified mining activity at the site by acquiring a very high-resolution satellite image.
The series of pools, laden with toxic mercury, where a waterway once flowed is a telltale sign of illegal gold mining.
At a second major mining site, activity paused during the government crackdown on illegal mining beginning in November 2024, only to restart soon after the law enforcement operation concluded.
Satellite imagery shows rapid expansion of mining at the site between July and November 2024.
This image is from July.
And this image is from November, when the government began its law enforcement operation.
Satellite imagery shows little or no mining during the operation, which concluded in January 2025.
But between March and October 2025, shown here, mining expanded significantly.
And it continued to expand through July 2026.
EIA estimates that roughly 30 hectares of forest (about 42 soccer fields) have been cleared at this site since the enforcement operation.
EIA used very high-resolution satellite imagery to verify the mining activity at the site.
Further north are two adjacent mining sites that began in early 2026.
The first signs of mining can be seen in satellite imagery from January 2026.
By May, the first site had grown significantly and deforestation was visible at a second site to the west.
By July, patches of deforestation spanned nearly 5 kilometers in the eastern site and 3 kilometers in the western one.
Very high-resolution satellite imagery confirms mining at the eastern site, where EIA estimates at least 17 hectares of forest (about 24 soccer fields) have been cleared.
The Munduruku are calling on the Brazilian government to:
1. Completely and permanently stop illegal mining and remove intruders from their territory
2. Establish a permanent state presence and continuous monitoring to prevent future intrusions
3. Provide assistance in developing sustainable economic alternatives that ensure Munduruku families can live with dignity and generate income without relying on illegal gold mining
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