A report released by Brazil’s top public health institute revealed that many Yanomami, the Amazon’s largest Indigenous tribe, have been contaminated with mercury from widespread illegal gold mining. The study was conducted in nine villages along the Mucajai River, a region heavily affected by illegal mining activities. Researchers collected hair samples from nearly 300 Yanomami individuals and found that 84% had levels of mercury contamination above 2 micrograms per gram. Some individuals even exceeded the 6 micrograms per gram threshold, which is associated with more severe health issues.
Exposure to mercury can lead to various health problems, including decreased sensitivity, weakness, dizziness, and compromised central nervous system function. Pregnant women who are exposed to mercury can also pass it along to their unborn children, resulting in developmental abnormalities. The study focused on methylmercury, a potent neurotoxin that is formed when bacteria metabolize inorganic mercury in rivers. Consumption of fish with high mercury levels is a common route of exposure for the Yanomami people.
The research findings align with prior studies on mercury contamination in the Amazon region, indicating that the problem is widespread and longstanding. The Yanomami territory, which is the size of Portugal and home to 27,000 individuals, has faced decades of illegal mining activities. The problem escalated during the presidency of Jair Bolsonaro, who weakened environmental protection agencies and encouraged mining on Indigenous lands. The current president, Luiz Inácio Lula da Silva, has made efforts to address the issue, but the removal of gold prospectors from Yanomami territory remains a significant challenge.
Global efforts to address mercury pollution led to the Minamata Convention in 2013, a UN-backed agreement aimed at curbing mercury emissions. Brazil was among the signatories of the treaty, which was named after a Japanese city where residents were contaminated by decades of mercury exposure. The study conducted by Brazil’s public health institute synthesizes three papers published in the journal Toxics, all based on the same fieldwork. The results underscore the need for urgent action to address mercury contamination in the Amazon and protect the health of Indigenous communities.
The Yanomami leader, Dário Kopenawa, emphasized the urgent need to expel illegal gold prospectors from Yanomami territory to prevent further contamination, devastation, and health issues. The study’s findings provide concrete evidence of the impact of mining on Indigenous communities and underscore the importance of addressing the mercury contamination crisis. Concerted efforts at the local, national, and global levels are necessary to protect the Yanomami and other Indigenous tribes from the harmful effects of mercury exposure resulting from illegal mining activities in the Amazon region.
