Impact of Gold mining on the Environment and Human. The study of gold sites in the Migori Gold Belt, Kenya, revealed that the concentrations of heavy metals, mainly Hg, Pb and As are above acceptable levels Tailings at the panning sites recorded values of 65–510 mg kg−1 Pb, 006–760 mg kg−1 As and 046–1920 mg kg−1 Hg Stream sediments had values …