- Enforcement against illegal gold mines in the Brazilian Amazon ramped up in 2023, but the contamination from the mercury used in mining will likely be felt for generations to come.
- According to a report from Brazilian think tank the Escolhas Institute, up to 73% of all mercury used in Brazil’s gold mines is of unknown origin; the country’s environmental agency states practically all mines in Brazil use illegal mercury.
- Mercury affects primarily children, who may be born with severe disabilities and face learning difficulties for the rest of their lives.
The return in 2023 of Luiz Inácio Lula da Silva to Brazil’s presidency marked a significant setback for illegal gold mining in the Amazon. During Lula’s first year in office, the federal environmental agency, IBAMA, destroyed 600 dredgers used to churn up riverbeds in search of gold, and 150 backhoe loaders doing the same on riverbanks.
However, the impact of illegal gold mines reverberates for dozens of years after they close. It’s not just the forests and rivers that may never be the same again; the mercury used by the miners continues to impact future generations.
“If we simply stop mining today and let nature regenerate itself naturally, there are estimates that this mercury will remain circulating in the environment for 100 years,” Paulo Basta, who coordinates studies on mercury contamination at Fiocruz, Brazil’s leading federal health research center, told Mongabay.
Mercury is widely used in the so-called garimpos, wildcat mines that undergo simpler environmental requirements than large-scale commercial mining projects. It helps separate the gold from the ore by sticking to it and forming a little ball, and is later burned off to leave behind just the gold.
The mercury evaporates in the process, but rapidly condenses and returns to nature in liquid form. Mercury contamination also happens earlier in the previous process, when the metal is mixed with the ore, during which some of it washes into the river.
“They do this work by hand,” Larissa Rodrigues, a researcher and portfolio manager at the Escolhas Institute, which advocates for sustainable development of natural resources, told Mongabay. “There’s no care, it’s very rudimentary.” The institute looked at Brazil’s mercury data after identifying a jarring discrepancy in public numbers: While gold exports and mining areas expanded rapidly in recent decades, legal imports of mercury plummeted.
“This is great evidence that there is a large illegal mercury market,” Rodrigues said, noting that Brazil isn’t a mercury producer and has to import all of it from abroad.
To estimate the size of the illegal mercury market in Brazil, the institute measured how much mercury would be necessary to produce all the gold officially declared from garimpos within four years. The researchers then compared this to the volume of legal imports.
The gap between these two figures indicates that at least 96 metric tons of mercury of unknown origin were used in Brazil from 2018 to 2022, representing 58% of all mercury used in the gold mines. A less conservative analysis puts it at 185 metric tons of illegal mercury, or 73% of the total. The Escolhas Institute published these findings in a report in early June.
But the problem may be much bigger. According to Jair Schmitt, IBAMA’s director of environmental protection, there has been practically no legal mercury available for mining in the country in the last few years. “Today, practically all the mercury used in Brazil for gold mining probably comes from illegal sources,” he told Mongabay. “It’s smuggled in somehow.”
Some clues about the origin of this mercury emerged from a raid in December 2022 by IBAMA and the Federal Police against a criminal organization allegedly smuggling mercury from Bolivia into Brazil. “Bolivia imports 10 times more mercury than Brazil to produce the same amount of gold from mining. The amount of mercury the country imports has no justification. It’s too high,” Rodrigues said.
In April this year, authorities also seized 100 kilograms (220 pounds) of mercury hidden in a car in Roraima state, on the border with Guyana.
“There are indications that people are using small planes to go to Central America to get mercury. They also enter via the land border. Brazil has a huge border, it’s highly complex to control this,” Schmitt said. Another ruse is to conceal the substance in shipments of other imported products. “For example, we once checked an import of shampoo, and what was inside the bottles was mercury.”
Children are the main victims
Once in contact with the water, mercury transforms into methylmercury, a toxic compound that can move up the food chain. It accumulates in high concentrations in carnivorous fish, which are an important source of food for local communities.
Mercury has a particularly profound impact on the health of Indigenous people, whose food and water often come directly from nature. In Brazil, mining in Indigenous lands is stricly forbidden, but that hasn’t stopped the spread of the garimpos: the total area affected by illegal mining in the Brazilian Amazon tripled in the past 20 years, according to a new report, much of it inside Indigenous territories.
One of the worst-affected Indigenous communities in the Brazilian Amazon are the Yanomami, who live in the border region of Amazonas and Roraima states and Venezuela. Fiocruz’s most recent research found mercury traces in all 300 Yanomami individuals tested by researchers. High contamination levels were also found among the Munduruku and Kayapo Indigenous communities in Pará state.
According to Fiocruz’s Basta, mercury acts mainly on the brain. In adults, it may cause a series of effects like tingling, ringing in the ears, trembling, weakness, memory loss and cognitive difficulties.
The most perverse effects, however, are borne by children. Mercury can pass from a pregnant woman to her child inside the uterus, and the baby may be born with rare neurological syndromes such as cerebral palsy. In less severe cases, they may experience delays in their neurological development, resulting in learning difficulties.
“Perhaps the main impact is the impairment of the cognitive capacity of these generations of children who are being born under the shadow of mercury contamination,” Basta said. “Contrary to what businessmen and politicians say, that mining is a vector of socioeconomic development, in fact it is a marker of social inequality.”
Experts say equipment already exists to reduce the risk of mercury contamination. The retorta, for example, is a kind of furnace where the mercury-gold mixture can be burned in an enclosed space, allowing the mercury to condense into liquid form inside safe storage. An added benefit is that it can then be reused.
According to Schmitt, however, it’s rare to find anyone using such equipment: “Although there may be techniques to minimize release into the environment, the absolute majority of these miners do not use this equipment.”
There’s also a cultural component at work. “People have been using mercury forever. It’s very deep-rooted,” Rodrigues said. It’s feasible to cut off mercury by implementing more sophisticated machinery to separate the gold from the ore. But there are no incentives from the gold market to do so. “Today you have gold mines that produce gold without using mercury, but what incentive does anyone have to do this? No market incentive.”
In mid-June, Nilto Tatto, a lawmaker who heads the environmental caucus in Brazil’s lower house of Congress, presented a bill proposing a mercury ban in mining, following Colombia’s example in 2018. The bill is under discussion.
The mercury trade in Brazil is overseen by IBAMA, which has a database of all the companies authorized to import the metal. In March, the federal government opened a public hearing on a new regulation on mercury. According to Schmitt, the plan is to track the substance all the way inside the country.
“And then you close in. You have to improve border control, customs control, and fight illegal mining,” he said. “You have to take various actions to stifle these criminal organizations so that they don’t have mercury for illegal mining.”
Banner image: Mercury being used to agglomerate gold. Image by Fabio Nascimento.
Organized crime brings renewed threats to Yanomami in Brazil
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