Impact of mercury use in artisanal gold mining on community health: Kahama case study, Tanzania

Abstract

This study is part of the main research carried out in 2010 which investigated social economic impact of uncontrolled artisanal mining on local communities and the environment using a case study of sampled gold mining sites in selected villages in Lunguya and Segese wards in Kahama District, Tanzania. The methodology involved a study sample size of 210 households forming 70% of the targeted mining villages. They were interviewed on various social economic variables related to artisanal mining and environmental issues in the study area. Interviews to respondents were counterchecked by medical laboratory examination records to validate the results on the impact of mercury use by uncontrolled artisanal mining activities on human health and the local environment at large. In short, uncontrolled artisanal miners' practices of site clearing of trees to give way .to open cast mining in extraction of ore; and washing processes involving use of mercury in shallow ponds which frequently acted as sources of domestic water compounded the polluting effects to human population in the study area. Laboratory investigation results indicated that there were mercury concentrations in soil and water ranged between 0.012 mg/kg in water to 0.85mg/kg in soil with pH ranged from 2.8 (acidic) in the water that miners re-used in the processing of gold ore, to 4.1 in the water pool, for example, at Kakola in Lunguya ward where residents used the same water for domestic purposes; while soil acidification recorded (2.7) pH. In the overall, 89% of interviewed respondents in the study area stated they partially benefited economically through self-employment gained from artisanal gold mining at the expense human health and environmental pollution and degradation in general. This study concluded that although the community in the study area apparently gained economic benefits from artisanal gold mining; the consequent public ill-health and environmental hazards outweighed the benefit gained. The study recommended to the government, law enforcers and other stakeholders at different levels to take immediate safety measures to ensure safe artisanal gold mining for sustainable development. This to be paralleled by community awareness building on the negative effects of poor mining methods in order to take collective remedial action for the welfare of the local community and the nation at large.