Exposure to metals that have recently come into use.

The possibility of deriving normal biological values for some rare metals is investigated. The metals under study are gallium, germanium, indium, niobium and tellurium, i.e. a group of metals with increasing utilization in the electronics industry. So far some data are unavailable for some of the elements, e.g. daily intake, oral absorption and half-life time for gallium, and body burden for gallium and germanium. Reliable values of blood concentration are available only for gallium, niobium and tellurium. The problem related to a proposed urinary biological limit value for tellurium is also discussed.