Kenya’s Artisanal Miners Trade Mercury for Machines Amid Major Industrial Discovery

In the red earth of Bushiangala, western Kenya, a quiet transformation is underway. For nearly a century, this land has yielded gold, first to colonial prospectors and later to generations of informal miners known locally as wachimba migodi. Now, as artisanal workers attempt to abandon toxic mercury processing methods, a separate seismic shift is occurring beneath their feet: the confirmation of one of the largest gold deposits found in Kenya in decades.

The dual developments present a complex future for Kakamega County. On one hand, the planetGOLD programme is helping miners organize into cooperatives and adopt mercury-free technology to protect public health. On the other, British firm Shanta Gold Limited has confirmed a US$5.29 billion gold discovery at its Isulu-Bushiangala underground project nearby, raising questions about land use, displacement and the place of small-scale miners in a changing economic landscape.

A Century of Extraction, A Decade of Contamination

Gold mining in Bushiangala dates back to 1931, when traces were found in the nearby Yala River. Although industrial operations dominated production until the 1950s, their collapse left behind an informal mining economy that has persisted for more than 70 years. For decades, miners dug, crushed, and washed ore by hand using techniques passed down through generations.

The introduction of mercury around 2008 changed the calculus. Introduced as a faster alternative for gold extraction, the chemical quickly took hold. However, it left behind contamination that has not disappeared. Water sources across the Lake Victoria region have become increasingly unsafe, with mercury levels in some wells reaching up to ten times the World Health Organization’s guidelines.

A 2026 study published in Environmental Health found that water and slurry used in these mining pits contain concentrations of arsenic, chromium, and mercury up to 100 times higher than local surface waters. The contamination stretches across a gold-rich belt including Kakamega, Vihiga, Siaya, Busia, and Kisumu, reaching toward Migori near the Tanzanian border.

For the miners, these toxins are no longer abstract data. Timothy Mukoshi, a miner who has worked the Kakamega gold fields since the late 1990s, remembers a colleague who slowly began to lose his memory. After the man died, a post-mortem found traces of mercury in his brain. “Mercury is what you call a leisurely poison,” Mukoshi says.

Formalization Through Cooperatives

In response to the health crisis, miners in Bushiangala are forming cooperatives and introducing methods that can recover gold without the toxic metal. The shift is supported by the planetGOLD programme, a global initiative backed by the Global Environment Facility (GEF) and led by the United Nations Environment Programme (UNEP), with implementation in Kenya by the United Nations Development Programme (UNDP).

The project, locally known as IMKA, partners with the Ministry of Mining and the Ministry of Environment to tackle the root cause of the mercury crisis: informality. Kakamega currently has 24 registered mining cooperatives spread across several gold-producing sub-counties. These structures allow miners to access training, equipment, and formal recognition under the Mining Act of 2016.

“When you are one woman with a gram of gold, you have no voice,” says Josephine Liabule Mkhobi, chairlady of the Bushiangala Women’s Mining Cooperative. “When Notice a hundred of you with a kilo, the buyers have to listen.”

Mechanical processing systems are replacing mercury inside the cooperatives. Miners who once relied on a capful of mercury are now learning to master gravity concentrators and shaking tables—mechanical systems that use physical force rather than toxic chemicals to pull gold from the dust. Kenya’s 2022 National Action Plan on artisanal and small-scale gold mining estimates that traditional manual methods recover only about 20 per cent of the gold in the ore. By comparison, data from planetGOLD Kenya shows that mercury-free mechanical systems can recover up to 90 per cent.

The Industrial Shadow

While artisanal miners work to formalize their operations, the region is also attracting large-scale industrial interest. British firm Shanta Gold Limited has confirmed a new US$5.29 billion gold discovery at its Isulu-Bushiangala underground project in Kakamega County. According to reports, the project includes plans for a large-scale underground mine with advanced technology and substantial infrastructure.

The Environmental Impact Assessment (EIA) report submitted to the National Environment Management Authority (NEMA) outlines plans for a mine covering about 337 acres in Kakamega South Sub-county. However, the expansion brings its own set of challenges. The Isulu-Bushiangala underground project will need about 337 acres of mostly private land and could displace nearly 800 households, its environmental impact assessment warns.

This creates a complex dynamic where artisanal miners are seeking legal recognition and land security at the same time a major industrial player is securing rights to the same geological belt. Anthony Munanga, Kakamega’s county director for environment, natural resources and climate change, notes that without organization, the gold economy remains largely invisible to regulators. His department is now mapping mining areas across the county to move miners into designated zones where licensing and environmental oversight become possible.

Financing Gaps and Implementation Delays

Despite the technical progress, financial constraints remain a significant barrier. The planetGOLD programme in Kenya was launched with a USD 4.24 million grant from the Global Environment Facility. Project documents estimate the programme could mobilize up to USD 26 million in additional financing from commercial lenders and private investors, but that funding has been slow to materialize.

A 2023 mid-term review found that much of the USD 16.6 million in co-financing from government and local partners existed on paper as in-kind contributions rather than cash available for day-to-day operations. A government moratorium on new mining licences between 2019 and 2023 froze formalization during a critical phase of the project. Without licences, miners could not meet standard lending requirements, and commercial banks have been reluctant to lend to what remains a largely informal sector.

For those on the front lines, that “deliberate sequencing” feels like a race against their own health. Merab Khamonya, a 28-year-old mother who joined the Bushiangala cooperative in 2024, is one of those caught in the lag between training and implementation. Though she has attended planetGOLD sessions, she still submerges her bare hands in basins of ore and mercury—a necessity for survival.

“I feel things moving inside my eyes,” she says, describing a persistent, painful irritation. “I know it harms me. I even see traces of it on my clothes when I go home to cook for my children.”

A Model for the Continent

Despite the hurdles, the Kenyan model is drawing attention beyond Kakamega. The system relies on cooperative structures at mine sites with county-level oversight through Joint Implementation Committees (JICs). The African Development Bank is using this JIC structure as a reference point for scaling mercury-free artisanal mining across the continent.

According to Ludovic Bernaudat, head of the chemicals and green chemistry unit at UNEP, Kenya’s experience is now being used to guide the next phase of the programme as it expands across Africa. The Kenyan model will be featured at the 2026 planetGOLD Global Forum in Panama, where nations share technical expertise and compare approaches to ending mercury use.

Back in Bushiangala, the test is only beginning. Miners still arrive at the pits each morning chasing thin seams of gold buried in the red earth. What is changing—slowly—is what happens after the ore reaches the surface. If the new system holds, the mercury that once flowed through these streams may eventually disappear, even as the land itself faces new pressures from industrial expansion.

As formalization efforts compete with large-scale industrial interests in western Kenya, how can policymakers ensure that artisanal communities retain their livelihoods while meeting environmental and safety standards?