非法采金导致亚马逊地区疟疾激增，这种关联比我们预想的更严重

Gold prices are at an all-time high, and we are very worried. As disease ecologists, it’s not the economic instability that concerns us, but the fact that a surge in gold mining could have a devastating impact on human health.

Our team of researchers from Stanford University, Universidade Federal de Mato Grosso, and Universidade Federal de Minas Gerais, Brazil, established and quantified the effects of illegal gold mining on a recent surge in malaria in the Yanomami territory in the Brazilian Amazon that plunged this isolated Indigenous population into a devastating health crisis in the early 2020s.

An executive push towards extraction

When Jair Bolsonaro became Brazil’s president in 2019, he made environmental deregulation a central tenet of his platform, claiming that environmental and Indigenous land protections hindered the country’s economic development. He also transferred the authority of Indigenous land demarcation from the National Indigenous Foundation (FUNAI) to the Agriculture Ministry.

Furthermore, he issued decrees aimed at deregulating small-scale mining activities in the Amazon region. The decrees made no distinction between regulated (therefore, legal) mining outside of Indigenous territory and mining within Indigenous land, which is universally illegal. Illegal miners flooded the Yanomami territory.

By January 2023, when Lula da Silva secured the Presidency as Bolsonaro successor, the number of illegal gold miners in Yanomami territory — the largest Indigenous territory in the Amazon — had surged to 20,000, roughly two-thirds the number of the local Yanomami population.

Malaria and the Yanomami health crisis

Weeks after Lula da Silva took office, independent news outlet Sumaúma released a dispatch citing shocking disease and malnutrition figures among the Yanomami. Threaded with images of suffering Yanomami people, the report motivated the president to declare a humanitarian crisis.

Dr. Andre Siqueira, a researcher from the Oswaldo Cruz research institute (Fiocruz) and a member of the team of doctors sent into the territory upon declaration of the crisis recounted: “The conditions of the population were devastating.” Nearly every person they tested was positive for malaria.

Even small increases in mining can cause a surge in malaria cases

The Sumaúma dispatch, and the Instituto Sociaombiental report upon which it was based, linked the influx of illegal gold miners during the Bolsonaro administration to the Yanomami health crisis and the proliferation of malaria.

As researchers who focus on how trends in land use contribute to the spread of parasites, we suspected that gold mining and malaria were not separate contributors to the same crisis, but part of one system of cause and effect devastating the territory and its people.

Illegal gold mining can drive malaria in multiple ways. First, when miners tear down forests and open gashes along the edges of rivers to access gold deposits, they create the ideal breeding grounds for the mosquito species that transmits malaria in the Amazon.

Second, when miners travel to the territory, potentially from malaria hotspots across South America, they can carry the parasite into the territory and increase its transmission.

Finally, small-scale gold miners often use mercury to cheaply and easily extract gold particles. This mercury is dumped into waterways across the region, poisoning the people who rely on the rivers for water and for fish, weakening their immune systems and making them more susceptible to malaria infection.

Thorough data on health and environmental conditions in the Amazon collected by the Brazilian Ministry of Health enabled us not only to confidently establish the link Indigenous people had long suspected, but to assign numbers to the relationship, making it concrete and actionable.

We were shocked by the results. The relationship was far stronger than we suspected. We found that every 0.03% increase in mining led to a 20-46% increase in malaria one to two years later, resulting in a 300% increase in malaria in the Yanomami territory between 2016-2023.

Understanding the association between gold mining and malaria underpinning the Yanomami health crisis is only one part of the puzzle. We hope that this research can serve as a tool to empower Indigenous communities with information about their health and inform policies that protect both human health and the environment. Our data indicates that by preventing illegal mining within Indigenous lands can protect their health and other important natural and cultural heritage.

Improving healthcare access

The Lula government is engaging in important efforts to expel illegal gold miners and establish health centers in the Yanomami territory. Though hospitalizations for malaria have decreased slightly since 2023, malaria rates among Yanomami remain high due to the lagged effect we identified in our research and the difficulty of access to timely diagnoses and treatment in remote regions.

Researchers are making strides to close this accessibility gap. An international team has developed “malakits”, which empower community members without formal medical training to diagnose and treat malaria on site. Such efforts are of critical importance given that the lagged effects of illegal gold mining will continue to cause elevated malaria incidence unless communities have broad access to treatment.

It is also important to ensure full land rights of Indigenous populations and empower them to defend their land. This is proven to be one of the most effective ways to fight deforestation and protect ecosystems.

Addressing the malaria crisis requires diversifying the rural Amazonian economy with an eye toward sustainability, such that people have options beyond mining and logging. Brazil is making strides toward this goal with the recent launch of a national bioeconomy development plan.

Informed consumers can prioritize purchasing recycled gold or refrain from purchasing gold at all to send a signal that further illegal gold extraction is not worth the human toll. As with the Blood Diamonds campaign in the early 2000s, real change can come from spreading the word about the human and environmental cost of illegal mining and demanding ethical supply chains.

Appeals to protect the Amazon region are often made on environmental terms. We want to make the case that saving the people in Amazon is also a global health imperative. Protecting the forest, investing in Indigenous land rights, fostering healthy economic opportunities for rural communities, and interrogating the role of gold in our global economy are all part of preventing the continued spread of one of the world’s deadliest infectious diseases.

Daniela de Angeli Dutra was funded by a grant from the National Institutes of Health (USA) awarded to Professor Erin Mordecai.

Riley Casagrande não presta consultoria, trabalha, possui ações ou recebe financiamento de qualquer empresa ou organização que poderia se beneficiar com a publicação deste artigo e não revelou nenhum vínculo relevante além de seu cargo acadêmico.