Illicit mercury is poisoning the Amazon

One of the deadliest chemicals on Earth is being smuggled across Latin America – and is poisoning the environment along the way.

Mercury is a powerful neurotoxin and its use is banned or heavily restricted throughout the world. But it's "essential" to illegal gold mining, one of the Amazon's "most destructive criminal economies", said The Associated Press,

Once extracted from the Earth's crust, mercury "persists in the environment indefinitely", said The Guardian. Those who drink water and consume food contaminated by it are gradually poisoned. But, with the current record-high gold prices, the mercury trade has become "so lucrative that one of Mexico's deadliest cartels has entered the business".

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The 'gold-mercury-drug trifecta'

Last month, Peruvian authorities seized about four tonnes of mercury hidden inside gravel sacks in a Mexican container on a cargo ship bound for Bolivia. It was the largest mercury seizure made in South America. Mercury mining in Mexico is "spinning out of control", according to a recent report by the non-profit Environmental Investigation Agency (EIA). More than 180 tonnes were trafficked from Mexico to Colombia, Bolivia and Peru between April 2019 and June 2025, as part of what the Washington-based organisation calls a "gold-mercury-drug trifecta".

Miners mix mercury with sediment and heat it until it vaporises, leaving the pure gold ore – and releasing toxic vapour into the air, water and soil. Leftover mercury washes into rivers, where it transforms into methylmercury: its most dangerous form. Artisanal and small-scale gold mining releases 800 tonnes of mercury into the rainforest every year.

In 2013, 128 countries signed up to the Minamata Convention and committed to restrict the production and export of mercury, before phasing it out by 2032. But "legal loopholes" in the UN-based treaty "benefit traffickers and illegal gold miners", said the EIA, warning that the trade is "fuelling violence, forest destruction", human rights abuses and "environmental devastation".

In Latin America, governments and law enforcement agencies have struggled to stem the flow. Peru and Brazil banned mercury imports in 2016 but, "in Bolivia, it is easier to import mercury than to import books or medicines", said Oscar Campanini, director of the non-profit Centro de Documentación e Información Bolivia.

'Profound impact'

The surge in mercury trafficking has been driven by soaring gold prices. According to World Gold Council estimates, 30% of gold mined around the world comes from "untraceable" sources – a $12 billion (£9 million) black market that has "created a toxic web of environmental degradation and public health risks", said AI Invest.

It's having a "particularly profound impact" on the health of Indigenous people, said Mongabay, a non-profit environmental media organisation. Communities that live near mining sites in the Amazon have been exposed to high concentrations of mercury. In Peru's Madre de Dios region, an "epicentre of illegal mining", mercury contamination has been detected in drinking water and even breast milk, said AP. Long-term exposure can cause "irreversible damage to the brain and nervous system, particularly in children and pregnant women".

There are equipment and methods that can replace mercury in the gold mining process, and reduce the risk of contamination – but there is currently little market incentive to adopt them.

The issue is "expected to take centre stage" at the Conference of the Parties to the Minamata Convention in November, where advocates "hope to eliminate legal loopholes" and enforce phase-out timelines. Authorities say last month's bust "marks a turning point in efforts to dismantle the supply chains".