In Peru’s Amazon women gold miners ditch toxic mercury

As gold prices surge, so has illegal mining in South America, destroying forests and polluting rivers, but women in eastern Peru are pioneering technology that does not rely on toxic mercury and even produces more of the precious metal. In parts of Madre de Dios, one of Peru’s most biodiverse regions, illegal mining has left a desert-like landscape strewn with lifeless craters and poisoned rivers.

“We cannot continue polluting and releasing more mercury into the environment,” said 65-year-old Victoria Condori, an artisanal miner with an 800-hectare (1,977-acre) concession employing 16 workers on the Madre de Dios River. Using heavy diggers, high-pressure hoses and a series of sluices, half a dozen miners can process around 20 metric tons of soil into 15 kg of black dirt that can contain anything from 20 g to 60 g of gold in about 12 hours.

Artisanal miners would then usually stir mercury into the mix to bind with the gold and extract it, but the process releases the toxic metal into the ecosystem, poisoning animals, people and rivers. Mercury is one of the top 10 chemicals of major public health concern, according to the World Health Organization, and is linked to developmental delays in children, cognitive impairment and damage to the kidney, lungs and immune system. Now, a group of women miners are replacing mercury with gravimetric, or shaking, tables, to filter the denser gold particles. The technique can also produce bigger yields and potentially raise prices from buyers demanding clean gold. “It’s possible to recover gold without using mercury or other chemicals,” said Vilma Contreras, head of the Tauro Fátima Artisanal Miners’ Association (AMATAF), at a roadside workshop with the constant thrum of the shaking tables behind her.

She said many miners opt for mercury because it is readily available and the process is less time-consuming. Gold prices have reached highs of more than $3,000 an ounce, due to fears of a global trade war triggered by US President Donald Trump’s tariffs. Gold prices rose nearly 30% in 2024. The price surge has spurred illegal mining across South America and brought a rise in deforestation, human trafficking, sexual exploitation and violent crime. But Contreras said AMATAF was expanding as more female miners sought a safer environment for their children and the prospect higher profits from selling to sustainable gold buyers and jewelry firms like Brilliant Earth, or local the Casa Collab. Some 30% of owners of formal mining operations in Madre de Dios are women, the highest proportion in Peru.

While the majority of miners operate illegally or informally, Contreras has invested to make AMATAF a formal mining association with 11 operations in Madre de Dios. Four of its concessions have Fairmined certification from the Alliance for Responsible Mining, attesting to the group’s efforts to mine in “an environmentally responsible manner”.

“It is costly to work in the formal sector because you have to put personnel on the formal payroll, you have to pay all the taxes,” Contreras said.

“But if you want to work with peace of mind and without anyone bothering you, you have to reach this stage.”

Other women miners in Madre de Dios want to follow and learn how to extract gold without mercury. Condori, filming every detail on her pink-cased phone, observed a gravimetric table in the Paolita II concession on the Madre de Dios River. “I’m always eager to learn more, every day, to improve our method,” she said.

Isabel Chua, 25, skillfully operated the shaking table, adding black silt containing the gold as water filtered over the sloped vibrating surface separating the heavier gold particles.

The gold dust is then heated with borax, a mineral salt, until molten, then a coin-sized nugget is dropped into a bucket of water to cool.

Pedro Ynfantes, 67, the owner of the 450-hectare concession, estimates he gains an extra gram of gold for every working day with the shaking table method, compared to using mercury. Madre de Dios is Peru’s most heavily mined Amazon region. It centers on La Pampa, between kilometer 98 and 110 of the Inter-Oceanic Highway, in the buffer zone of the mega biodiverse Tambopata National Reserve. The town and the surrounding wasteland are starkly visible in the green rainforest to tourists flying into the regional capital Puerto Maldonado to visit jungle ecolodges.

The presence of mining machinery and illegal miners in La Pampa increased by 900% between 2021 and 2024 to more than 1,331 dredgers and around 10,924 miners, according to a 2024 report by NGO Conservación Amazónica.

The report also found the area deforested in Madre de Dios had increased by 67,000 hectares in 10 years, representing 52% of the total deforestation in 38 years. While certain jewelry companies are willing to pay a premium for mercury-free gold, the women do not get any extra when they sell it locally, said France Cabanillas, local coordinator for U.S.-based non-profit Pure Earth.

“Adapting to mercury-free technologies, like any new relatively new technique or practice, is a little bit complicated,” Cabanillas said.