Environmental monitoring of the Kafue River, located in the Copperbelt, Zambia

Zambia is a country with an extensive mining industry with the majority of mines located in the Copperbelt province. Through this region of the countr y, the Kafue River drains and receives effluent water from mining activitie s as well as from other industrial point sources. In addition, production o f agricultural products and pest control requires use of different pesticid es in the area. Information on industrial and agricultural pollution has no t been clearly identified in Zambia, and little attention has been paid to pollution control and possible impact of metals, pesticides, and other pers istent compounds in the environment. The objective of this study was to int roduce and to evaluate a few methodologies based on in situ bioassays for e nvironmental assessment to promote sustainable and environmentally sound wa ter resource management of the Kafue River. The results show that caged thr eespot tilapia exposed downstream of industrial points sources rapidly bioa ccumulate several trace elements, ic., Cd, Co, Cu, Cr, Ni. These elements a lso occurred in much higher concentrations in water samples downstream of t he industrial area compared with a locality upstream. Furthermore, the use of a semipermeable membrane device (SPMD) for passive absorption of lipophi lic pollutants in the water showed relatively high concentration of several pesticides, i.e., DDT with major metabolites, PCB, and dieldrin. The prese nt study shows that only 2 weeks of in situ studies in waters contaminated by pollutants affects in situ exposed fish and that the correlation between water and tissue concentrations was relatively good. Both trace elements a nd persistent organic pollutants occurred in such high concentrations that they must be considered from ecotoxicological aspects and may affect aquati c animal health.