ABSTRACT
This chapter provides a detailed discussion on the occurrence and production, uses, chemical and physical properties, exposure and exposure limits, toxicokinetics, and effects of uranium in humans. Uranium is a moderately common element, found in most rocks, with greatest concentrations (8 ppm) in acidic igneous rocks (granites). Several complex minerals of uranium are of commercial importance, including carnotite, pitchblende, and tobernite. The latest recovery process involves extraction by the bacterium Thiobacillus ferroxidans, followed by electrolytic reduction, and precipitation as "green cake", the tetrafluoride, which is further converted to the metal, oxide, hexafluoride, and so on. Small quantities of uranium are used in ceramics, glass, and for various chemicals. All naturally occurring uranium isotopes are radioactive. The effects of uranium in humans include information on acute toxicity, chronic toxicity, biochemistry, specific organs and systems, teratogenicity, mutagenicity, and carcinogenicity.
