The impact of pollution from a mercury processing plant in KwaZulu-Natal, South Africa, on the health of fish-eating communities in the area: an environmental health risk assessment

The objective of this study was to determine the human health risk associated with fish consumption in a contaminated area downstream from a mercury processing plant in KwaZulu-Natal, South Africa. The study population consisted of fish consumers living in close proximity to the u'Mgeni River and the Inanda Dam downstream from the plant. A control group was selected from the area upstream from the mercury plant as far as the Nagle Dam. Total daily mercury consumption per kilogram body weight per day was calculated for each person included in the study. These data were compared with the tolerable daily intake standard published by the World Health Organization, as well as to the United States Environmental Protection Agency's reference dose. Human hair samples obtained from the study population and a control group were analysed for mercury content. The results of the risk estimation indicated that the study population is at risk. Human hair samples, however, indicated that dangerous levels of mercury had not yet been consumed. Humans in this study area could be subject to an excessive health risk from mercury as a result of their fish consumption. Fish mercury levels in the contaminated area should be monitored closely.