Mineral and trace elements (Al, B, Ca, Cu, Fe, K, Li, Mg, Na, P and Zn) in 24 hour human urine samples from approximately 100 healthy persons (age between 20 and 50 years) were analysed by ICP (Inductively Coupled Plasma) and DCP (Direct Current Plasma) emission spectroscopy. The obtained values can be taken as "reference values" owing to the large number of individual samples. Mean values and the range of substance concentrations and substance excretion per 24 hours are given. Physiological reference values are reported for Ba, Sr and Ti, which are of particular interest in the field of occupational medicine; examples of increases in these three elements as a result of exposure at the work place are also given. Additionally some average values for Cd, Co, Ni and Pb have been measured by a voltammetric technique.