Environmental Consequences Related To Poor Adherence To Standard Mining Practices By Artisanal And Small Scale Miners: The Case Of Ashiraq Mines, Tanzania

Abstract

This study assesses the contribution of small scale mining towards environmental degradation. Field observation, insitu

measurements and laboratory analysis were conducted to determine environmental consequences caused by poor adherence to

standard mining practices by artisanal and small scale miners in Ashiraq Mines in Tanzania. Field observation revealed

significant land and soil disturbance in the study area such as the existence of abandoned old workings. Direct measurements

of pH values for water samples from the nearby river revealed higher acidity on the downstream than the upstream side of the

river. Estimates of Mercury concentrations in the atmosphere showed a significant addition of Mercury due to amalgam

burning. Also laboratory analysis of water samples from the nearby river was done using the Atomic Absorption Spectroscopy

(AAS) to determine Mercury contents in surface water. The analysis revealed high levels of Mercury concentrations in

downstream water above recommended values. Mercury contents for the upstream samples were relatively lower than the

upstream values but also lower than the recommended values. The study also recommends different measures to be undertaken

by regulatory authorities to improve awareness and adherence to standard mining practices for artisanal and small scale miners,

to reduce environmental consequences related to small scale mining.