Abstract

In artisanal and small-scale gold mining (ASGM) liquid mercury (Hg0) is applied to extract gold from ore. Miners and community members in ASGM areas are constantly exposed to elemental mercury vapour, and depending on the local situation to ingestion of methyl-mercury from local fish and/or rice. Mercury is a toxic substance that causes negative health effects, depending on the susceptibility of the individual; and on the dosage and duration of the exposure. Our own studies showed that mercury levels in any analysed biomarker were higher compared to control groups or reference values. Highly exposed workers showed in up-to 80% typical signs of chronic mercury intoxication, mainly neurological symptoms like ataxia, tremor and coordination problems.

ASGM affects approximately 15 Million miners globally causing a serious public health problem. Our burden of disease study for Zimbabwe showed that chronic mercury intoxication ranks within the top 20 health hazards of the country. Other possible health hazards due to mining are accidents in tunnels, shafts and open pits. Other hazards are noise and dust and lead. Baseline data for these hazards are too insufficient to estimate the real risk for the health of miners in ASGM. To obtain more data integrated assessments are necessary. To analyse mercury laboratories with appropriate equipment and trained staff are needed. Health care providers need training to be able to diagnose and treat chronic mercury intoxication. Intoxicated people need proper treatment. Appropriate health care centres in ASGM have to be set up and funded. Regular human-biomonitoring should be established to be able to identify hot spots, and to evaluate intervention programs. The awareness, that mercury is a serious health hazard, is the key to required urgent actions, and needs to be increased on all levels, from national policymakers, regional stakeholders, to health experts and the population in mining areas.