Environmental distribution and risk of exposure of Heavy Metal Pollutants from Lolgorian Artisanal Gold Mining in Kenya

Aquatic Mercury Pollution from Artisanal and Small-Scale Gold Mining in Sub-Saharan Africa: Status, Impacts, and Interventions

“…In the same period in the Migori-Transmara ASGM region, high Hg was detected in sediment (430 µg/kg), soil (140 µg/kg), and tailings (8900 µg/kg) and was associated with wet and dry depositions [65]. In recent investigations, Tampushi et al [66] reported 0.66 mg/L in surface water and 24.63 mg/kg Hg in sediments, positively correlated with ASGM ore and tailings contamination sources in the Lolgorian mining region of southwestern Kenya. In Kakamega and Vihiga counties, soil samples contained Hg levels about 49% above the USEPA standards with 1-72% bioaccessibility.…”

“…Regional Summary and Intercontinental Hg Pollution from ASGM Table 2 reflects the overall trend in countries in sub-regions of sub-Saharan Africa, South America, and Asia where evidence of ASGM contributing to aquatic Hg pollution has been documented. Hg concentration in Eastern Africa's aquatic systems ranged from 5.8 ng/L in the Napoleon Gulf, L. Victoria, to 1.21 mg/L in the Namukombe stream, Uganda, and from 0.36 µg/L in the L. Victoria Basin rivers to 0.66 mg/L in the Lolgorian region in Kenya [54,64,66]. In the Alebedia area in River Nile State, Sudan, Ahmed et al [70] reported 0.001 to 0.005 mg/L Hg in surface water.…”

“…Campbell et al [51] reported 629 ng/g Hg in sediments of L. Victoria, while Ikingura et al [59] documented maximum Hg concentrations of 6 mg/kg in stream sediments around the Mugusu mine of the L. Victoria Basin of Tanzania. In Kenya, Tampushi et al [66] investigated Hg release into stream sediments at the Lolgorian ASGM site, where maximum Hg concentrations reached 24.6 mg/kg. In Sudan's Dar Mali gold mining region, stream sediment Hg concentrations ranged between 0.001 and 0.005 mg/kg [71].…”