Chromium toxicokinetics

These experts collectively have knowledge of chromium s physical and chemical properties, toxicokinetics, key health end points, mechanisms of action, human and animal exposure, and quantification of risk to humans. All reviewers were selected in conformity with the conditions for peer review specified in Section 104(I)( 13) of the Comprehensive Environmental Response, Compensation, and Liability Act, as amended. 

The primary purpose of this chapter is to provide public health officials, physicians, toxicologists, and other interested individuals and groups with an overall perspective on the toxicology of chromium. It contains descriptions and evaluations of toxicological studies and epidemiological investigations and provides conclusions, where possible, on the relevance of toxicity and toxicokinetic data to public health. 

An age-related difference in the extent of gastrointestinal absorption of chromium(III) was reported in one study (Sullivan et al. 1984) it is not known if a similar relationship would exist for chromium(VI). No other information is available which evaluated potential differences between adults and children. Toxicokinetic studies examining how aging can influence the absorption, distribution, and excretion of chromium, particularly chromium(VI) would be useful in assessing children s susceptibility to chromium toxicity. There are no data to determine whether there are age-specific biomarkers of exposure or effects or any interactions with other chemicals that would be specific for children. There is very little available information on methods for reducing chromium toxic effects or body burdens it is likely that research in adults would also be applicable to children. 

Bragt PC, van Dura EA. 1983. Toxicokinetics of hexavalent chromium in the rat after intratracheal administration of chromates of different solubilities. Ann Occup Hyg 27(3) 315-322. 

The toxicokinetics of a given chromium compound depend on the valence state of the chromium atom and the nature of its ligands. In contrast to chromi-um(III), which is bound to plasma proteins such as transferrins, chromium(VI) entering the blood stream is taken up selectively by erythrocytes, reduced, and bound predominantly to hemoglobin. 

Chromium (Cr) toxicokinetic is the toxicokinetics of two different oxidation states, Cr(III) and Cr(VI), linked by reduction processes that are ubiquitous in body fluids and tissues. The kinetic behaviors of these two major oxidation states of chromium are very different. Reduction of Cr(VI) to Cr(III) in the body, the lung, and the gastrointestinal tract is sufficiently rapid that bulk chromium kinetics may be considered to be the kinetics of Cr(III). However, certain detectable differences in chromium disposition depend upon whether exposure is to a Cr(III) or a Cr(VI) salt. In addition, the reduction process itself is of interest relative to the carcinogenicity of Cr(VI) in the lung. Therefore, a comprehensive understanding of the toxicokinetics of chromium must include the disposition of both Cr(III) and Cr(VI). 

The important features of Cr(III) and Cr(VI) toxicokinetics are discussed in this chapter. The picture they form is consistent with present understanding of chromium disposition and toxicity. However, great uncertainties remain. Data gaps and uncertainties are identified and discussed in Sect. D. 

Goulle JP, Saussereau E, Grosjean J, Doche C, Mahieu L, Thouret JM, et al. Accidental potassium dichromate poisoning. Toxicokinetics of chromium by ICP-MS-CRC in biological fluids and in hair. Forensic Sci Int 2012 217(l-3) e8-12. 

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