Accumulation of heavy metals in freshwater organisms: Assessment of toxic interactions

Heavy metals are continuously released into the terrestrial environment by natural sources and human activities. The uptake and accumulation of heavy metals by plants promotes a mechanistic understanding of the biological sig nificance of particular metal concentrations and distributions in biota, Th e toxicity of chromium, zinc, copper and cobalt ions and their binary mixtu res are studied at varying test levels using duckweed as the test organism. The accumulation of metal ions are determined by atomic absorption spectro scopy. The type of toxic interactions in binary mixtures is assessed as 'sy nergistic', 'antagonistic' and 'additive' by a statistical approach.