Contamination of water and food crops by trace elements in the African Copperbelt: A collaborative cross-border study in Zambia and the Democratic Republic of Congo

Background. Environmental pollution by trace metals is of concern in the African Copperbelt, a region of intense mining situated on either side of the border between the Democratic Republic of Congo (DRC) and Zambia. Scientists from both countries undertook a collaborative study using the same sampling and analytical methodologies to assess metal contamination of water and food in both countries.Methods. In six mining areas (Lubumbashi, Likasi, Kipushi in DRC; Chingola, Kitwe, Luanshya in Zambia) samples of water (surface, boreholes, taps) and various crops were collected in two residential sites near mining operations, and in rural villages farther away (controls). Nine elements (Mn, Co, Ni, Cu, Zn, As, Cd, Pb, U) were measured by ICP-MS or ICP-OES.Results. In drinking water obtained close to mining, the median concentrations (µg/L) of all trace elements, except Zn, were substantially higher in DRC (n=20) than Zambia (n=18), this being most pronounced for Pb (27 vs 0.08), Cd (0.7 vs