Methodology for the assessment of human health risks associated with the consumption of chemical contaminated freshwater fish in South Africa

Studies have shown that the aquatic environment can be polluted by contaminates that are accumulated by freshwater fish and this may pose a health risk to the consumers of the contaminated fish. Developed counties like the United States of America have developed strategies and associated guidance documentation to conduct chemical contaminant surveys using fish and to use these data to reduce the heath risk to the consumers of the fish. In this paper a generic methodology is presented that will give guidance in the undertaking of fish contaminant surveys to provide information regarding the possible health risk if the fish are consumed by recreational and subsistence fishermen in South Africa. The fundamentals of the methodology are based on catchment information, socio-demographic information of consumers of fish in the catchment, bioaccumulation potential and health risks of analytes, sound sampling design, risk assessment procedures and performing monitoring at different scales and depths. These aspects are presented as 10 major steps in the methodology of which the basic requirements are discussed to focus the surveys and optimise the application of resources. Although the methodology focuses on assessing the possible health risk to the consumers of fish many of the aspects would apply to any investigation aimed at assessing the chemical contaminant levels in fish. Furthermore as these surveys identify areas in the aquatic system where fish have unacceptably high chemical contaminant levels, this information can be used in catchment management programmes to put remedial actions in place that would ensure that the fish populations of the system are fit for present and future human consumption. Water SA Vol.29(1) 2003: 69-9