Chromium Toxicity, High-Valent Chromium
Chromium(VI) (Cr(VI), hexavalent chromium) is an established human carcinogen and a major occupational and environmental hazard. Toxic properties of Cr(VI) are related to its ability to enter cells easily and to form reactive high-valent (Cr(VI), Cr(V), and Cr(IV)) intermediates on the way to stable Cr(III) products. In recent years, significant progress has been made in the understanding of chemical properties and biological roles of such intermediates, using physicochemical techniques such as electron paramagnetic resonance and X-ray absorption spectroscopies. The potential of biological oxidation of Cr(III) to Cr(VI) (via Cr(IV) and Cr(V)) intermediates has also been recognized as a likely link between the toxicity of Cr(VI) and antidiabetic activities of Cr(III), which highlights the potential danger of long-term use of Cr(III) nutritional supplements.
The authors are grateful for support from two Australian Research Council (ARC) grants to PAL for an ARC Professorial Fellowship (DP0984722) and for an ARC Senior Research Associate position for AL (DP1095310).
- Levina A, Codd R, Dillon CT, Lay PA (2003) Chromium in biology: toxicology and nutritional aspects. Prog Inorg Chem 51:145–250Google Scholar