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Mercury poisoning from Artisanal and Small-scale Gold Mining (ASGM) is crippling Kenya’s Biodiversity

Mercury pollution from Artisanal and Small-scale Gold Mining (ASGM) in Kenya is causing widespread ecological harm, threatening biodiversity, food security, and public health. The use of mercury in gold extraction contaminates soil and water, leading to toxic methylmercury buildup in aquatic ecosystems, which bioaccumulates through the food chain and disrupts entire ecosystems. Counties like Migori, Siaya, and Kakamega are among those most affected. Despite being a signatory to the Minamata Convention, Kenya lacks robust regulations to control mercury use in ASGM. To protect ecological resilience and meet global biodiversity targets, there is an urgent need for policies that phase out mercury use, promote safer mining alternatives, and support miners through technical and financial assistance.

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.

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Under this program, CEJAD aims to eliminate the risk posed by exposure to lead in paints to women and children, and improve the regulatory frameworks to phase out lead in paint at national, regional and international level.

Our work under this program aims to promote the phase out of Highly Hazardous Pesticides (HHPs) from use, especially in agriculture to protect human health and the environment. The use of HHPs is threatening the lives of vulnerable populations, food systems, biodiversity and the environment at large.

Our work under the Mercury Program aims to protect human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds in line with the Minamata Convention on Mercury, a legally binding global treaty adopted in 2013. Kenya is a party to the Minamata Convention.

The Montreal Protocol, adopted in 1987, protects the ozone layer by regulating ozone-depleting substances (ODS), such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). It mandates the phase-out of CFC and HCFC production and consumption with specific timeframes for different Parties, based on their status as a developed or developing country.

Our work under this program aims to reduce the health and environmental impacts associated with waste and plastics throughout their life cycle. Over the years, plastic and plastic products have emerged as problematic and hazardous to human health and the environment.