We’d be as mad as hatters not to tackle the mercury poisoning the Amazon.

6 min readNov 22, 2018


By Dean Muruven, WWF Global Freshwater Policy Manager

Small scale gold mining in the Amazon © Diego Perez / WWF-Peru

Almost every civilization has myths about mercury. From talismans to the promise of longevity and good health, humans have always had some connection to this silvery wonder that is the only metal to be liquid at room temperature — a unique quality that saw it being used to measure sick children’s temperatures across the globe.

But mercury is no longer used in thermometers. Indeed, it is hard to believe it ever was given what we now know about this extremely toxic element. Illnesses were often associated with mining and using mercury. The term “as mad as a hatter” — a lighthearted phrase today — appears to have originated from the serious mercury poisoning suffered by northern English hatmakers, who used mercury in their manufacturing process in the 1800s and often ended up losing their minds. And eventually their lives.

Today, we know all we need to know about the dangers of mercury — the incurable damage it does to people and animals. The threat it poses to communities and entire ecosystems. Yet it is still being used in industrial quantities by artisanal and small-scale miners across the world because of one of its many extraordinary qualities — its ability to react with an even more alluring metal, gold. It’s really (and sadly given the consequences) simple — add mercury to gold bearing ore, boil off the mercury and you’ll be left with pure gold. But the price is extremely high because the toxic vapours and waste poison not only the miners but also the air and rivers. And the people and wildlife downwind and downstream…

Children in canoe on Amazon tributary © Camilo Diaz WWF

This is what is happening to the Amazon river basin — the world’s most biodiverse ecosystem and home to around 34 million people.

And why WWF has just released Healthy Rivers, Healthy People at the 2nd Conference of the Parties (COP) to the Minamata Convention on Mercury (you’ll hear more about this in a few paragraphs time!). This new report highlights the dangers that mercury pollution poses across the Amazon and calling for urgent action to reduce the use of mercury in small-scale gold mining to protect the world’s largest river system and the people and species that depend on it.

Tens of thousands of artisanal and small-scale gold miners (ASGM) are currently digging a precarious living out of the Amazon, providing some income for themselves and their families but also producing an estimated 71 per cent of all mercury emissions in the basin. Already, 5,840km of rivers and creeks have been destroyed, while over 28,000km of downstream waterways have potentially being contaminated with mercury.

This invisible pollution has already harmed the health of an estimated 1.5 million people as well as countless fish, birds and iconic mammals such as river dolphins and jaguars. A study cited in the WWF report found that 81 per cent of carnivorous fish had detectable levels of mercury, while another showed that 26 per cent of river dolphins had mercury levels above the recommended World Health Organization level for people.

River dolphins in Tarapoto Lakes © Jaime Rojo / WWF

Unlike the all-too-visible deforestation, mercury pollution is both invisible and largely ignored despite growing evidence of the dangers it poses. Urgent action is needed tackle this toxic threat before it severely undermines the health, productivity and quality of life of people, including indigenous groups, across the Amazon — along with hopes of sustainable development.

But this phenomenon is not restricted to South America. Mercury is used by artisanal and small scale gold miners in many countries. According to the latest Global Mercury Assessment, ASGM is the largest single activity causing mercury releases worldwide. Alarmingly, the Assessment also found that mercury emissions from human activities had increased by 20 per cent in just 5 years.

Which brings us back to the Minamata Convention. Named after a city in south-western Japan where thousands of people suffered and died in the 1950s from mercury poisoning after eating fish and shellfish contaminated with mercury that was released in the wastewater from a chemical plant, the Minamata Convention was the first global environmental agreement negotiated in the 21st century — with the primary objective of protecting human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds.

Ensuring that countries ratify and then implement the Minamata Convention is the best opportunity we have to “make mercury history” and protect people and nature — from the Amazon to the Congo to India — from this pollutant.

Currently underway in Geneva, second COP has brought together an extremely diverse group of professionals to help tackle this toxic threat. You have dentists who are concerned with mercury in dental amalgam, doctors and toxicologists worried about the health impacts of mercury, engineers and technology providers displaying their solutions, and biologists and conservationists studying the impact on species and the environment.

That’s a lot of brain power that we can dedicate to solving the mercury challenge and that is arguably the greatest strength of the Minamata Convention: it creates the opportunity to break the silos that we are so used to operating in.

WWF as a conservation organization cannot solve the mercury challenge in the Amazon on our own. We are going to have to step out and engage the health sector and technology providers as well as traders, sellers and consumers along the gold supply chain. We are going to explore bankable projects that provide a better return on investments to the ASGM sector and move them away from using mercury so that their livelihoods no longer poison them and the river system.

The threats are real. Now we need real partnerships to find and implement new solutions in the Amazon. For example, in a very welcome development, the Global Environment Facility (GEF) has increased its funding for mercury programmes to US$206 million in its new funding cycle: countries in the Amazon and beyond need to seize this opportunity and work the right partners to address the mercury challenge.

The tragedy in Minamata that came to light in 1956 was the result of a poisoned food chain, illustrating once again how inextricably linked we are to the natural world. And yet, we continue to pollute, poison, poach and pave our way through the world’s biodiversity. As the recent Living Planet Report made clear, we are continuing to destroy species populations — with freshwater species populations suffering an 83 per cent drop since 1970. If we do not reverse this trend swiftly, the consequences for us all will be dire.

This is why WWF is calling for a new Global Deal for People and Nature for now at another COP that is underway right now on the Convention Biological Diversity in Egypt. We don’t have time decades of negotiations. Countries need to agree an ambitious agenda in 2020 and then fulfill their global commitments. And that includes ‘making mercury history’ in the Amazon and other river basins around the world.

Golden sunset in Leguizamo in the Amazon river basin © Luis Barreto / WWF-Colombia




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