Mercury exposure in a low-income community in South Africa

To establish whether a specific community in a gold mining area, with potentially associated small-scale gold mining activities, was exposed to mercury.

The community was situated in Mpumalanga, where some potential sources of mercury emissions may have an impact. Adults >or=18 years were considered eligible. Biological monitoring, supported by questionnaires, was applied. Thirty respondents completed the questionnaire which covered demographics, energy use, food and water consumption, neurological symptoms, and confounders such as alcohol consumption and brain injuries. Mercury levels were determined in 28 urine and 20 blood samples of these respondents.

Three (15%) of the blood samples exceeded the guideline (<10 microg/l) for individuals who are not occupationally exposed, while 14 (50%) of the urine samples exceeded the guideline for mercury in urine (<5.0 microg/g creatinine) for those not exposed occupationally. The cause of these elevated levels is unknown, as only 20% of respondents indicated that they used coal as an energy carrier. Furthermore, nobody from the community was reportedly formally employed in a goldmine. Nineteen (63%) respondents consumed locally caught fish, while 20 (67%) drank water from a river.

Some individuals in this study may be occupationally exposed to mercury through small-scale gold mining activities. As primary health facilities will be the first point of entry for individuals experiencing symptoms of mercury poisoning, South African primary health care workers need to take cognisance of mercury exposure as a possible cause of neurological symptoms in patients.