Reflections on hexavalent chromium: health hazards of an industrial heavyweight.

Chromium has been used commercially in the United States for more than 100 years in metal alloys and other compounds, as a pigment, and in the tanning and metal plating industries, and many studies have looked at its effects in terms of occupational health. But, although scientists know that Cr(VI) is a human carcinogen and that it can cause other deleterious health effects including kidney and liver damage, certain questions remain about the metal's effects, such as which routes of exposures are dangerous for humans.