Hunger for gold means the Amazon has reached 'tipping point' of mercury contamination from illegal mining
The rising value of gold worldwide has amplified il‐ legal mining in the Ama‐ zon, where liquid mercury is being dumped in the Amazon River and causing scientists to warn that In‐ digenous communities and the environment could pay a far greater price.
Three weeks ago, Colom‐ bia, Brazil and the United States partnered up to de‐ stroy 19 illegal gold mining dredges in the Amazon Rain‐ forest. According to Reuters, the dredges were producing about $1.9 million Cdn in gold.
The dredges scoop mud from riverbeds and miners mix in liquid mercury, which causes gold particles to stick together, making them easier to find. Authorities involved in the operation said it tar‐ geted the Familia del Norte criminal group, which they said was dumping 114,000 grams of mercury into the wa‐ ter every month while mining gold.
The partnership between countries to destroy the dredges is the first of its kind in the area — but it's only made a dent in the overall problem. Considering these mining methods are cheap and extremely profitable, ex‐ perts suggest the cost of one dredge can be made up with‐ in a week.
In the wake of the COVID19 pandemic, illegal mining has intensified, and the re‐ sulting mercury pollution has devastating and long-lasting impacts on the health and culture of communities that depend on the Amazon River.
Mercury poisoning has long been associated with ad‐ verse effects on the nervous system, and new studies show it may pose a risk to car‐ diovascular and immune sys‐ tems, too, according to Niladri Basu, a professor at McGill University who holds a Cana‐ da Research Chair in Environ‐ mental Health Sciences.
He noted in an email to
CBC News that those health effects can mean a "dimin‐ ished quality of life in affected individuals, families and com‐ munities."
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'Explosion in gold min‐ ing'
Many South American coun‐ tries saw a huge increase in il‐ legal gold mining during the pandemic.
The involvement of orga‐ nized crime in the mining pro‐ cess mean the areas became more violent, so guards in protected national parks were unable to report to their posts, resulting in a lack of
government surveillance.
"During the past two years, there's been an explo‐ sion in gold mining and the use of mercury and cyanide in gold mining in the Ecuadorian Amazon," said biologist Jenna Webb, a member of CoPEHCanada, a community of re‐ searchers interested in global ecosystems and health.
She's been living in the Ecuadorian Amazon for the last seven years and says it now looks "a little bit like Madre de Dios in 2008."
That protected area of once pristine rainforest in southern Peru is now referred to as a "wasteland" thanks to what government officials es‐ timated to be around 40,000 illegal miners.
According to Webb, one gram of mercury — about the amount in an old-fashioned thermometer — is enough to contaminate an eight hectare lake. "So that's one relatively small lake, but still … a whole lake — that's just one gram."
She says the amounts of mercury dumped into the wa‐ ter by mining operations are "orders of magnitude larger than that."
Once it's in the water, We‐ bb says bacteria transform the mercury into methylmer‐ cury, a neurotoxin. Fish eat plants where the bacteria live and the neurotoxin builds up in their bodies — a process called bioaccumulation. That buildup is passed along to hu‐ mans if they eat contami‐ nated fish.
Methylmercury can be passed from mother to child and can also slip through the barrier that usually protects the brain from toxins.
This is why Webb and oth‐ er experts suggest people take care when consuming fish. "We say, 'Don't eat fish that eat other fish.' "
Marine biologist Diego Luis Muñoz Sosa notes the conta‐ mination can spread far bey‐ ond the initial area.
"There are fish that are great migrants that travel through all the Amazonian rivers," he said. "We have to take into account, for exam‐ ple, everything that happens in Peru, in Madre de Dios, in Bolivia, in Brazil itself, in Venezuela."
Impact hard to mea‐ sure
The best known example of mercury contamination took place in Japan in the 1950s when mercury was dumped into Minamata Bay by indus‐ try and absorbed by fish and shellfish. Thousands who ate that seafood came down with a severe form of mercury poi‐ soning that came to be called Minamata disease.
In 2013, Canada signed the Minamata Convention on Mercury, a global treaty that came into force international‐ ly in 2017 and included a ban on new mercury mines and the phase-out of existing mines.
The extent of mercury contamination is often hard to measure because the effec‐ ts aren't always instanta‐ neous, but over time it can have a huge impact.
In Canada, the northern Ontario community of Grassy Narrows became contami‐ nated with an estimated 10 tonnes of liquid mercury dumped by a nearby paper mill.
As a result, the Grassy Nar‐ rows First Nation, which relies on fish from local lakes and rivers, has dealt with health impacts for generations.
Mercury is usually mea‐ sured by micrograms. For ref‐ erence, a grain of salt is about 60 micrograms. Hair or blood samples can be tested to de‐ termine how much mercury is in a person's body.
A journal in 1978 reported that people from Grassy Nar‐ rows First Nation had levels of up to 158 micrograms per litre (μg/L) of mercury in their blood, almost eight times more than the 20 μg/L deemed safe for adults by Health Canada.
WATCH | 'I'm afraid for my grandkids': Impact of mercury poisoning on Grassy Narrows:
In South America, testing is more commonly performed on hair samples because they are particularly useful in de‐ tecting methylmercury.
A University of Cartagena, Colombia, document from 2018 notes that hair samples taken in 2005 in Sai Cinza, Brazil, showed levels of up to 90 micrograms per gram (μg/g). That's 15 times more than the six μg/g deemed safe for adults in Canada.
The same document cited a 2008 study from Bolivia showing samples from kids living along the Beni River with mercury levels of up to 34.1 μg/g — 16 times more than the two μg/g that Cana‐ da deems safe for children.
Marc Amyot, Canada's Re‐ search Chair in Ecotoxicology and Global Change, said those numbers are concerning.
"If they are getting it from food then it's methylmercury — that's a potent neurotoxi‐ cant." Amyot has been re‐ searching contaminants and water since the 1990s.
Organized crime in‐ volvement
Muñoz, the marine biologist, says the involvement of orga‐ nized crime adds to the com‐ plicated nature of illegal gold mining.
"Illegal armed guerrillas are involved; trafficking not only gold, but also arms and drugs," said Muñoz, whose work at the Frankfurt Zoologi‐ cal Society Colombia (FZS) aims to protect national parks and Indigenous communities in the area.
According to Muñoz, satel‐ lite imaging shows that there are around 100 dredges in Brazil and about 14 in Colom‐ bia.
Muñoz believes the recent destruction of the 19 dredges won't make much of a dent in profits, as miners can make enough to cover the cost of a lost dredge within a week.
The dredge destruction took place in the Puré and Puréte Rivers, which are about 150 kilometres apart and flow across both coun‐ tries and eventually into the Amazon River on the Brazilian side.
On the Colombian side, the Puré River flows into the Río Puré National Park, where officials know of at least one uncontacted community.
Muñoz explains that the Indigenous communities liv‐ ing in these national parks are in remote and often inaccessi‐ ble areas.
Global impact
Sandra Valenzuela, the direc‐ tor of World Wildlife Fund Colombia, stresses that illegal gold mining and deforesta‐ tion is displacing these uncon‐ tacted communities — as well as exposing them to disease.
She notes this has already happened to Nukak, an In‐ digenous community in Colombia that was displaced more than 30 years ago and who are particularly vulnera‐ ble to the flu and measles.
"Changing their surround‐ ings is affecting their whole way of living and their own way of protecting them‐ selves," said Valenzuela.
"The illegal mining in the Amazon is accelerating and arriving at a tipping point," she said. "This is a public health issue, but also it is a transnational crime. We need to bring others into the table, like Interpol."
She says the increasing value of gold means mining operations rely more on ma‐ chines that allow them to go further into protected Indige‐ nous areas. According to the World Gold Council, the price of gold has gone up 40 per cent since December 2019 — double the growth of the pre‐ vious five years.
Peru is one of the top 10 producers of gold in the wor‐ ld, generating 125 tonnes of gold in 2022. Followed by Brazil at 86 tonnes, Colombia at 60 tonnes and Bolivia at 53 tonnes. Though it's the small‐ est of the three, Bolivia is one of the world's leading mer‐ cury importers, bringing in 165 tonnes in 2020.
All of these countries have also signed the Minamata Convention.
"It seems really far away from Canadians, but it's actu‐ ally not," said Webb, the biol‐ ogist, pointing out that Cana‐ da imports gold.
In 2018, Canada imported $460 million worth of gold from Peru. In just one year, that number jumped to $2.5 billion and has since hovered around that same level. Ac‐ cording to the most recent Canadian data on the gold trade, Peru and Brazil are the top two countries exporting gold to Canada.
"It's just that the system is designed so that we won't ask questions about where it is coming from and what the impact is," said Webb. "The system is designed to blind us at every turn."