Jeovane de Jesus Aguiar was knee-deep in mud in the 100-yard gash he had cut into the Amazon rainforest, filtering brown water out of a pan, when he found the small, shiny flake he was looking for: a mixture of gold and mercury.
Mr. Aguiar had drizzled liquid mercury into the ground in his makeshift gold mine on the eastern edge of the small South American nation of Suriname, just as he had every few days.
The toxic element mixes with gold dust and forms an amalgam he can pluck out of the sludge. Then he sets the mixture aflame, burning off the mercury into the air, where winds spread it across the forest and across borders, poisoning the plants, animals and people it finds.
Left behind is the gold. That part usually ends up in Europe, the United States and the Persian Gulf, most often as expensive jewelry.
Twenty minutes along the river, the Wayana Indigenous community is getting sick. The Wayana eat fish from the river every day and, in recent years, many have been suffering from joint pain, muscle weakness and swelling. They also say birth defects are rising.
Tests show that the Wayana have double to triple the medically acceptable levels of mercury in their blood. “We’re not allowed to eat certain fish anymore,” said Linia Opoya in June, showing her hands, which ache after meals. “But there’s nothing else. That’s what we’ve always eaten.”
Driven by global scientific consensus that mercury causes brain damage, severe illnesses and birth defects, most of the world’s countries signed a groundbreaking international treaty in 2013 committing themselves to eradicating its use globally.
Yet 10 years later, mercury remains a scourge.
It has seriously harmed thousands of children in Indonesia. It has contaminated rivers throughout the Amazon, creating a humanitarian crisis for Brazil’s largest isolated tribe. And worldwide, doctors still warn against eating too much of certain fish because the toxic metal floats into the ocean and is absorbed into the food chain.
Suriname, a forested nation of 620,000 people on the northern edge of South America, is a case study in how mercury has become so intractable in large part because of society’s insatiable appetite for gold.
For decades, mercury has poisoned much of Suriname’s population. Nearly one in five births result in complications such as death, low birth weight or disabilities, according to one study, twice the rate of the United States. Yet mercury has also fueled the nation’s economy; gold accounts for 85 percent of Suriname’s exports, most of it mined with mercury.
“I could work without mercury,” said Mr. Aguiar, 51, overlooking his open pit. “But it wouldn’t be profitable.”
Suriname has banned mercury, yet the substance is easily smuggled in and widely used.
The Surinamese government did not respond to multiple requests for comment.
While Western countries, including the United States, have largely phased out mercury, more than 10 million people in 70 countries — mostly poorer nations across Asia, Africa and Latin America — still use the toxic element to extract gold from the ground, according to the United Nations.
These small-scale miners produce a fifth of the world’s gold — and nearly two-fifths of the world’s mercury pollution, according to the United Nations and the U.S. Environmental Protection Agency. Mining is the leading source of mercury emissions, ahead of coal-fired power plants.
“This is the brutal face of poverty,” said Achim Steiner, chief of the U.N. Development Program. For many miners, “the fact that mercury might harm me in 10 years’ time is too far from the reality of survival,” he added.
Large-scale gold miners use centrifuge machines or arsenic, which does not seep into the environment. Small miners choose mercury because it is cheap, easy to use and still available.
“Mercury, for better or worse, is a very simple technology, used for the better part of 2,000 years,” said Luis Fernandez, a Wake Forest University professor who has studied small-scale gold mining. “You can learn how to be a miner in 15 minutes, and you get pretty good results.”
While many countries have banned mercury in mining, enforcement is lax, Mr. Fernandez said. Gold mining “is an economic pressure valve for poorer countries,” he said. And that has only been compounded by the 12-percent rise in gold prices over the past year, to nearly $2,000 an ounce.
In 2013, the international community signed a broad treaty to take mercury off the market. It was called the Minamata Convention, named for a Japanese city where decades of industrial mercury pollution caused neurological diseases in more than 2,200 residents and even poisoned the city’s cats, causing them to jump into the sea.
Under the convention — which 145 nations, including Suriname, have now ratified — countries pledged to ban new mercury mines, close existing ones and, with some exceptions, halt the import and export of mercury.
The United States and European Union have since banned virtually all mercury exports, leaving the United Arab Emirates, Tajikistan, Russia, Mexico and Nigeria as some of the largest exporters. Researchers believe that China, which adopted the treaty, remains the world’s largest user of mercury.
The Minamata Convention, however, did not target small-scale gold mining. “Evidence has shown time and again that if you ban something that people need and there is no alternative, you simply drive them into illegality,” Mr. Steiner said.
Where Mr. Aguiar lives along the Maroni River, which forms the boundary between Suriname and French Guiana, everyone is either a miner or works for one. About 15 percent of Suriname’s work force, or 18,000 people, is connected to the gold mining industry, one of the highest percentages in the world, according to studies by the University of Amsterdam.
At the mines, workers shoot pressurized water to wash away generations of sediment, cutting into the landscape and exposing the layer they hope contains gold. Then they throw mercury into the water so it will bind naturally with any gold below.
The mercury is not hard to come by — and experts believe that much of it arrives from China.
A few hours before Mr. Aguiar was tossing mercury into his mine, where he employs seven people, he docked his canoe at one of the dozens of Chinese merchants on the banks of the Maroni. The shops sell the same goods: Coca-Cola, instant noodles, condoms and mercury. Mr. Aguiar bought a kilogram in an unmarked prescription drug bottle for $250. If he is lucky, it will be enough to mine a half-kilogram of gold, which he can sell for roughly $25,000.
Elsewhere in Suriname, vendors posted listings on Facebook and cabdrivers offered mercury connections. People across the country said mercury sellers were overwhelmingly Chinese, and interactions with several Chinese sellers revealed that they had little concern that they were doing anything illegal; mercury was a product like any other.
The Organization of American States said this year that mercury in Suriname was probably “imported from China on container ships bringing in other goods, such as mining equipment.”
In South America, researchers believe, only Bolivia imports mercury legally.
“So the question is: Where does it come from?” President Chandrikapersad Santokhi of Suriname told reporters in May. “We know it’s smuggled.”
Dr. Wilco Zijlmans, a pediatrician in Suriname who has studied the health effects of mercury, said its impact was clear. In a 2020 study of 1,200 Surinamese women that he helped conduct, 97 percent had unsafe levels of mercury in their bodies.
In addition to the elevated rate of birth complications, Dr. Zijlmans also found that children in Suriname were far more likely today than a generation ago to have delayed brain development, decreased motor skills and worse language and social abilities.
The effects are also showing up across the border. The Wayana Indigenous community has about 1,000 members spread across Suriname and French Guiana, which is French territory. Those in French Guiana have French citizenship, and French doctors have tracked the spread of mercury in some of their villages, which are surrounded by more than two dozen gold mines.
“Eventually, this will become like Minamata, too,” said Ms. Opoya, the Wayana member, who lives in one of the villages on French territory.
Upriver, when Mr. Aguiar wants to cash in, he takes his haul to the Chinese merchants who sell him the mercury. Those merchants then head to the hundreds of small gold-buying shops dotted across Paramaribo, Suriname’s capital.
At one shop, the owner, Arnaldo Ribeiro, said he buys just about all the gold that comes through his doors but has little idea where it comes from or whether it has been mined with mercury.
He then resells it to Kaloti Minthouse, a joint venture between the Surinamese government and a gold importer based in the United Arab Emirates.
“We don’t have to prove provenance,” Mr. Ribeiro said of the gold he sells.
Kaloti Minthouse then legally exports the gold around the world.
That means gold like Mr. Aguiar’s, cleaned of its mercury residue, is shipped off to become bank bullion, a necklace or perhaps a wedding ring, all its documents in order.
