Indium and its inorganic compounds – Evaluation of assessment values in biological material
Assessment values in biological material – Translation of the German version from 2024
Bernhard Michalke1Hans Drexler2 (Head of the working group “Assessment Values in Biological Material” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
Andrea Hartwig3 (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
MAK Commission4
1 Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Research Unit Analytical BioGeoChemistry, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
2 Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute and Outpatient Clinic of Occupational, Social, and Environmental Medicine, Henkestraße 9–11, 91054 Erlangen, Germany
3 Institute of Applied Biosciences, Department of Food Chemistry and Toxicology, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
4 Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Germany
Abstract
The German Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) summarized and evaluated the data for indium [7440-74-6] and its inorganic compounds to derive a biological guidance value (BLW) or a biological reference value (BAR) considering all toxicological end points. Relevant studies were identified from a literature search. Herein, background concentrations in serum of control sample donors were compared with those of exposed workers. Only one publication reported values in urine aside from serum values, both showing no correlation to indium concentrations in air. None of the studies detected any relationship between external and internal exposure. It was also not possible to derive a concentration at which toxicity occurs. Background concentrations reported in several studies overlapped with the serum indium concentrations from other studies of exposed subjects having already significant adverse effects. An explanation cannot be deduced from the available data. The relevant concentrations furthermore are very low, meaning that laboratories have to work close to their limits of quantitation, which consequently leads to a high error scattering. Accordingly, no BLW and no BAR could be derived.
