Mercury pollution from Artisanal and Small-scale Gold Mining (ASGM) is not only exposing communities to mercury poisoning, but also disrupting Kenya’s biodiversity. Ecological resilience, an ecosystem’s ability to resist, absorb, and recover from disturbances, is disrupted at its core.
Studies have shown that areas near gold mining spots face a high risk of mercury pollution, with high levels of the toxic metal found in water, sediment, and fish. ASGM activities are dominant in at least 7 counties, namely Migori, Siaya, Kakamega, Narok, Vihiga, Nandi, and Turkana counties.
How, then, does the mercury from gold extraction infiltrate the ecosystem? Majority of ASGM miners rely on mercury to recover gold through the amalgamation process, where mercury is mixed with crushed gold-bearing ore to form a soft mercury-gold amalgam. This amalgam is then heated, causing the mercury to vaporise and leaving behind the extracted gold. The tailings, waste materials containing residual mercury, are frequently dumped on the ground or near mining sites. Poor tailings management and rainfall can lead to mercury leaching into soils and seeping into underground water or being washed into nearby rivers and streams. Once in aquatic ecosystems, mercury can convert into methylmercury, a highly toxic form that bioaccumulates in fish and biomagnifies up the food chain, posing severe risks to biodiversity, public health, and food security.
The impact of mercury pollution in Kenya’s aquatic ecosystems is far-reaching. A recent study under the Minamata Convention framework reveals that mercury contamination disrupts entire food chains, not only threatening fish populations but also the predators, including birds and mammals that rely on them. This creates a cascading effect across biodiversity, as the mercury poisoning runs through all the connected chains, including humans.
The contamination in soil and water kills plants and suppresses crop growth, affecting pollinating insects exposed to contaminated nectar and soil microorganisms vital for soil health and plant reproduction. This threatens soil fertility, forest regeneration and agricultural productivity. Biodiversity is taking a silent beating.
This crisis speaks directly to Target 7 of the Kunming-Montreal Global Biodiversity Framework, which calls for reducing pollution to a level that is not harmful to biodiversity and ecosystems. Current loopholes in the importation and trade of mercury allow mercury to be diverted from its legal industrial uses into informal gold mining operations. This further threatens biodiversity as a huge population of miners still uses mercury in gold extraction.
Despite being a party to the Minamata Convention, Kenya lacks a comprehensive law regulating mercury use in artisanal and small-scale gold mining (ASGM). There is an urgent need to promote and support the transition to mercury-free gold recovery methods. While funding is a critical component, broader structural and policy support is equally essential. This includes providing technical training, access to appropriate equipment, and creating enabling environments for miners to adopt these safer, more sustainable alternatives like gravity concentration methods.
Protecting Kenya’s biodiversity and food security requires urgent action to phase out mercury use in ASGM, coupled with policies that support sustainable mining methods and ecosystem restoration. A structured phase-down leading to a complete phase-out is essential to give miners time to adapt without risking their livelihoods.
With over 800,000 Kenyans relying on ASGM, we must protect our ecosystems, food security, and natural resources. Mercury use in gold mining is doing more than just poisoning our soils, rivers and aquatic lives; it is crippling our ecological resilience.