A review, with 68 refs., discusses the impact of naturally occurring forms and compds. of Cu on its living environment, e.g. microorganisms, plants, animals, and man. The various sources of emissions, from Cu mining to the different processing stages as well as intermediate and final products and Cu scrap are dealt with. The toxicity of Cu is discussed in detail. Final subjects are the occurrence of Cu in wastewaters and sewage sludges as well as Cu recovery processes.