- The chief component of sand and a substance responsible for lung disease and cancer. Crystalline silica of respirable size is primarily quartz dust occurring in industrial and occupational settings in the form of fine, breathable particles. Respirable crystalline silica results from mining and grinding coal. In the year 2000, crystalline silica of respirable size was upgraded by the U.S. government to a "known human carcinogen." There are increased lung cancer rates in workers exposed to respirable-size (breathable) crystalline silica, primarily quartz and crystabolite, that are generated during sandblasting and similar activities in an occupational setting.
* * *The chief constituent of sand, hence of glass. SYN: silicic anhydride, silicon dioxide. [Mod. L. fr. L. silex (silic-), flint]
* * *sil·i·ca 'sil-i-kə n the dioxide of silicon SiO2 that is used as an ingredient of simethicone and that occurs naturally in crystalline, amorphous, and impure forms (as in quartz, opal, and sand respectively) called also silicon dioxide
* * *sil·i·ca (silґĭ-kə) [L. silex flint] SiO2, silicon dioxide or silicic anhydride, occurring in nature as agate, sand, amethyst, chalcedony, cristobalite, flint, quartz, and tridymite. It is one of the major constituents of dental porcelain and a common filler in resin composites; in granular form it serves as a dental abrasive and polishing agent. See also silicosis.
Medical dictionary. 2011.