The indigenous Munduruku people of the Brazilian Amazon are confronting a devastating health crisis, with women reporting widespread miscarriages and a growing fear of pregnancy due to mercury contamination in their lifeblood, the Tapajós River.
Alessandra Korap, a Munduruku community leader, shared the community's anguish with Sky News. "Many women end up losing their children," she revealed. "Either they can't get pregnant, or they lose their [foetus] over time. So, women are afraid of getting pregnant."
The Hidden Poison in the Water
For generations, the Munduruku have inhabited lands across the northern Brazilian states of Amazonas and Pará. In recent decades, however, villages have been plagued by a mysterious array of debilitating symptoms. These include children unable to lift their heads, adults losing the ability to walk, muscle tremors, memory loss, and fading hearing and vision.
Researchers have now identified the cause: the Tapajós river is heavily contaminated with highly toxic mercury. Gabriela Arrifano, a professor of mercury toxicology at the Federal University of Pará, explains that diagnosis is difficult as symptoms mimic degenerative illnesses like Parkinson's. However, she states there is now "enough evidence to relate the signs and symptoms found in people exposed to mercury."
The source of the poison is not in doubt. "We have robust evidence that mercury emissions to the environment comes from illegal gold mining activity," Professor Arrifano confirms from her laboratory, where she analyses hair and blood samples.
How Gold Mining Fuels a Health Catastrophe
Despite gold mining being outlawed on indigenous territory in Brazil, vast areas are scarred by illicit mining pits. This illegal trade is fuelled by record-high global gold prices and operates hand-in-hand with organised crime, using the same routes through the rainforest and laundering drug money.
The extraction process is the root of the problem. To isolate gold, miners churn up riverbeds and use mercury, which binds to the precious metal. This releases mercury into the air, water, and soil. Over time, it accumulates in the river fish that are a staple of the Munduruku diet.
One study found one in five fish in northern Brazilian markets contained dangerous mercury levels. Once ingested, the toxin enters the bloodstream and travels to the brain, causing lesions. It can disrupt nearly every bodily system, including reproductive, nervous, and skin health.
Professor Arrifano details how people's visual field shrinks, robbing them of peripheral vision. "This is very hard for people who live in the forest that need their complete senses," she notes.
The consequences are deeply personal for Alessandra Korap. While she experiences tingling hands and brain fog, her niece cannot walk or talk. She suspects this is linked to the girl's grandfather being a fisherman, leading to high mercury ingestion during the mother's pregnancy.
The toxic metal accumulates in placentas and breast milk, with children often showing levels two or three times the safe threshold for pregnant women. A nationwide study identified 668 cases of mercury poisoning, but this is considered a vast underestimate.
A Rising Tide Against a Crackdown
The administration of President Luiz Inácio Lula da Silva has launched a widespread crackdown. The environmental agency IBAMA conducts raids, destroying mining equipment and torching makeshift camps.
These efforts have yielded some success; in the Yanomami Indigenous Territory, illegal mining areas were reduced by 94% between 2023 and 2025. However, Adalberto Maluf, a national secretary in the environment ministry, admits the soaring price of gold makes the fight "harder."
"We thought that the amount would be reduced, and initially it did," Maluf told Sky News. "But I think it's not going as fast as we wanted... mainly because the price of gold continues rising."
This global demand creates a relentless pressure. Julia Yansara of the Financial Accountability and Corporate Transparency Coalition explains that high prices drive illegal miners into new areas and attract new criminal groups.
Capitalising on the global attention during the COP30 climate talks in Belém, the Munduruku peacefully protested, forcing a meeting with officials. This action successfully secured legal rights to two further portions of their territory.
For Alessandra, this fight is existential. "If we don't fight, we are crushed, we are taken over," she says. She appeals to the international gold buyers, who she believes are unaware "what is happening to our bodies, to our lives" as a result of their purchases.
