In the gold-rich fields of Kenya's Migori County, where nearly 40% of the population depends on artisanal and small-scale gold mining, a silent crisis is unfolding.
A new study by the Friedrich Naumann Foundation for Freedom - Kenya (FNF-Kenya) has uncovered dangerously high levels of mercury contamination, sounding the alarm over a growing public health and environmental disaster.
According to the study, published in April 2025 and based on data collected during field visits in October 2024, mercury--the toxic metal used to process gold--is polluting water, soil, and surrounding ecosystems at alarming rates. Tests conducted on water, soil, fish, and mining tailings near active sites revealed mercury concentrations far above national and international safety thresholds.
Water samples near mining hotspots showed mercury levels up to 100 times higher than the safe limit for drinking water, as set by the World Health Organization (WHO) and Kenya's National Environment Management Authority (NEMA). Soil and tailings from the mining areas contained mercury concentrations two to three times above levels deemed safe for agriculture, raising fears that the toxic metal may be entering the local food chain.
At Nyangoto River--just six kilometres from a mining zone--water samples revealed mercury levels more than 30 times the recommended limit. Fortunately, fish samples from the same areas showed no detectable mercury traces, for now.
"We found a huge gap in data. The number of people engaged in mining in Migori is still an estimate, and there's little information on the health effects of mercury exposure. This could be just the tip of the iceberg," said Stefan Schott, Project Director at FNF-Kenya.
The study also highlights the wider socio-economic toll of gold mining in the region. School dropout rates are rising as children abandon classrooms to join the mining industry. Meanwhile, entrenched gender inequality persists: men mine underground while women process the ore--breaking stones, washing, and extracting gold--but women are paid less, face sexual harassment, and lack representation in decision-making.
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"Both roles are vital in the gold production chain," the report notes, "yet women continue to face systemic discrimination."
The study urges immediate regulatory intervention to address the health and environmental threats posed by mercury exposure in Migori County. It also advises communities to avoid water sources near mining sites to reduce the risk of contamination.
"Mercury exposure in mining is a serious public health hazard," said Nashon Adero, a mining survey expert and contributor to the report. "It paints a grim picture I call the 'Vicious 9Ds of Mining'--displacement, disputes, dispossession, deprivation, destitution, disease, degradation, deformity, and death. Yet, mining done right can be a powerful tool for inclusive economic growth."
The report recommends stronger regulatory enforcement, equitable wage structures, and targeted community education on safer mining practices. It also calls for gender-responsive policies that empower women economically and protect their rights in the mining sector.
Conducted between October 11 and 30, 2024, the field study involved community outreach, environmental testing, and interviews with miners and stakeholders in Migori's mining sector. The research sought to document the social, economic, and environmental challenges of artisanal mining, and propose sustainable solutions to mitigate its ecological footprint.
