Toxikologische Bewertung von Ochratoxin A: Offene Fragen und Forschungsbedarf

Ochratoxin A (OTA) is an important food and feed contaminant with potential adverse effects in humans and animals. In view of present discussions on limit values for OTA in foods, essential elements of a toxicological risk assessment are outlined. The exposure situation in Europe is now well documented. The data base, with respect to a characterization of hazard and dose-response relationships, allowed to calculate a provisional tolerable daily intake for OTA suited to protect the consumer against undesirable toxic effects. Nonetheless, further research on OTA is indicated in view of unresolved issues regarding the following points: 1. mechanisms of action (mode of genotoxicity, role of bioactivation/metabolism, identification of DNA-adducts and dose-dependency); 2. combinations of OTA and other mycotoxins (studies of relevant mixtures/conditions); 3. individual susceptibility and/or situation-based vulnerability. Better information on mechanistic aspects of mycotoxin-induced toxicities will further improve our knowledge on the "margin of safety" between a given exposure and a potential impairment of human health.