Pregnant women in the Munduruku indigenous territory, in Pará state, North Brazil, have mercury levels in their bodies 4.5 times higher than the safe limit established by the World Health Organization (WHO). The maximum safe level is two micrograms of the metal per gram of hair (µg/g), but the levels found in these women average 9.1 µg/g.

The data are part of preliminary findings in a study conducted by the Oswaldo Cruz Foundation and were presented Wednesday (Jun. 3) by the research coordinator, Paulo Basta, during Rio Nature & Climate Week, the climate week in Rio de Janeiro.

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Of the 195 women surveyed, 97 percent have mercury levels in their bodies above the safe threshold. In the most extreme case, one woman had 39.9 µg/g of the metal – 20 times the tolerable limit.

Of this total, 134 women have given birth, and their babies are also being monitored. About 90 percent of them are already born with mercury contamination, as the metal passes from mother to child through the placenta. The babies have average concentrations of 5.8 µg/g, three times the limit. In one extreme case, one of them had 30.8 µg/g, 15 times the safe level.

“This baby is monitored at various intervals throughout the first two years of life. We track growth curves, weight-for-age ratios, height, and other metrics. Our hypothesis is that prenatal exposure to mercury causes delays in these neurodevelopmental milestones,” Paulo Basta said.

“Mercury converts into a neurotoxin that primarily affects the tissue of the central nervous system. Damage to the central nervous system is irreversible. People will have to deal with this problem for the rest of their lives,” he added.

The researcher cites an increase in the number of children born with rare neurological disorders, syndromes, congenital anomalies, and conditions for which a definitive diagnosis has not yet been established. All of these are suspected of being linked to mercury contamination. He also noted that the district where the Munduruku indigenous territory is located was the one that requested the most wheelchairs from the Ministry of Health.

“These data must be turned into official statistics, which did not exist in Brazil until very recently. Our system does not yet have a reporting form for specific cases of mercury contamination,” he stated.

“Despite these limitations, we have 751 identified cases of indigenous people contaminated by mercury with laboratory confirmation. Of this total, 318 are from Pará and 378 are from Roraima, home to the Yanomami people,” he added.

Illegal mining

The region where the Munduruku people live has been affected by illegal gold mining for decades, and mercury is used to separate the gold from the soil. This contaminates the rivers and the life forms in them, and the metal enters the human body primarily through the consumption of contaminated fish.

“Our main source of food is fish, and there’s no escaping that. For those who live in the city, it’s easy. They go to the grocery store, buy chicken and meat – they have other options. It breaks my heart to see the plight of these people, because they have no way to leave their territory and go somewhere else,” indigenous leader Alessandra Korap Munduruku said.

“This is our land. Why do we have to give up our land to companies, gold mining, mining, hydroelectric dams, and railroads? Why is indigenous people’s meat cheaper? It’s as if we didn’t exist. What kind of progress is this that kills rivers, forests, and drives people out?” she asked.

Representatives of ancestral territories launched the Alliance of Traditional Peoples and Communities: Guardians of the Atlantic Forest. The launch took place at the University of São Paulo Law School on National Atlantic Forest Day. The Atlantic forest is one of Brazil’s most threatened biomes.

Formed by representatives from indigenous and traditional peoples from across the country, the alliance was organized to represent and defend the Atlantic forest, as well as to fight for the territorial rights of these peoples and communities.

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“We are traditional peoples and communities, guardians of ancestral knowledge, which enables us to care for mother nature, her forests, rivers, lakes, and seas,” the alliance’s founding manifesto reads.

Ivanildes Kerexu, coordinator of the Guarani Yvyrupa Commission and a resident of the Rio Bonito Village in Ubatuba, São Paulo, said that the alliance is an initiative to unite peoples and to further protect this territory.

“We need to form this Atlantic forest alliance so that we can have the right to public policies and, of course, also for environmental preservation,” she said.

“What has preserved the Atlantic forest to this day has always been the traditional communities that live there and are resisting,” she added.

Federal Representative Sonia Guajajara, former Minister of Indigenous Peoples, who attended the launch ceremony, emphasized the role of the movement as a space for dialogue, reporting abuses, and building community.

“For us, it’s obvious – our daily struggle is not always understood by legal institutions. That is why these voices are needed every day, so that this message reaches everywhere, and is understood,” she declared.

In addition to the consequences of exploitation, mining, and deforestation, Guajajara argued, Brazil now faces an international threat linked to the exploitation of rare earths and critical minerals.

“If rare earths are exploited in the same way – without regard for rights, without safeguards, and without free, prior, and informed consultation – the consequences will be no different from what oil exploitation has meant for our peoples,” she went on to say.

For this reason, she noted, the creation of this coalition comes at a very opportune moment. “We are up against powerful structures – both economic and political – that have no desire whatsoever to understand what we do as a contribution to life on the planet. So, this forum of traditional communities in defense of the Atlantic forest is gaining strength at a key moment, a moment when more than half of the Atlantic forest has already been lost.”

Atlantic forest

Considered the common cradle of Brazilian history and biodiversity, the Atlantic forest is threatened by large-scale development projects and real estate speculation. Other factors that have also contributed to its destruction, according to members of the alliance, include exploitative tourism – particularly the construction of new resorts – the use of pesticides and the extraction of oil and fossil fuels.

Data on the biome reveal that only about 12.4 percent of its original vegetation remains today – vegetation that once covered 15 percent of Brazilian territory. Despite this, the forest still shelters over 20 thousand plant species and over 2 thousand vertebrate species, many of which exist nowhere else in the world.

The Atlantic forest is also vital to the economy and human life, as it provides water for more than 145 million Brazilians – that is, about 70 percent of Brazilians.