Trace element research-historical and future aspects.

During the last 30 years the International Society for Trace Element Research and the Nordic Trace Element Society has been active . During this period the importance of these elements for human diseases has been increasingly recognized, including their contribution to the global burden of disease. New analytical methods allow biomonitoring data to be related to health outcome. Future research using modern chemical methods will focus more on elemental speciation and on measuring lower concentrations leading to further identifying adverse effects and critical organs. Extensive knowledge about essentiality and toxicity of trace elements in humans has emerged during the last two decades and at present the difficulties in defining a range of acceptable oral intakes for essential elements has largely been overcome. Biological monitoring of trace element concentrations in various media such as blood or urine is of great importance and an overview is given. As an example, a more detailed description of biological monitoring of cadmium is given, explaining biokinetics including the role of metallothionein in modifying kinetics and toxicity. Finally future challenges related to risk assessment of newly developed metallic nanomaterials and metal containing medical devices are discussed.