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 osmium in humans. Osmiridium, an alloy of platinum-group metals, is the major natural source of osmium. The chief world source of osmiridium is South Africa. Most osmium is recovered as a by-product of copper refining in the United States. Platinum-group metals or gold placer deposit mines in Alaska, California, Oregon, and the Rocky Mountain States contribute part of US osmium production. Osmium imparts hardness to alloys used for mechanical pivots, phonograph needles, bearings, and engraving tools. Osmic acid synovial injections are used to treat rheumatoid arthritis. The effects of osmium in humans include information on acute toxicity, chronic toxicity, biochemistry, specific organs and systems, teratogenicity, mutagenicity, and carcinogenicity.
