Fracturing quartz produces silica-based radicals on the fracture planes and generates hydroxyl radicals (.OH) in aqueous media. .OH production has been shown to be directly associated with quartz-induced cell damage and phagocyte activation in vitro. This .OH production in vitro is inhibited by desferrioxamine mesylate, an Fe chelator, indicating involvement of a Fenton-like reaction. Our objec...

Interleukin-10 (IL-10) can downregulate expression of several proinflammatory cytokines including chemokines. This study investigated the role of IL-10 in the acute response of the rat lung to quartz particles. Intratracheal instillation of rats with 1 mg of quartz produced an inflammatory and cytotoxic response demonstrated by increased bronchoalveolar lavage (BAL) fluid neutrophils, lactate d...

Following the classification of quartz as a human carcinogen by the IARC, many standard-setting committees are currently trying to convert this hazard into their national or EU standards. Since human data to set a safe exposure limit for quartz are limited, we hypothesized that lung burden data on quartz in coal miners' lungs after lifetime exposure could be used to set a non-carcinogenic lung ...

three intrusive granitoid bodies from northwest saveh, central iran, are embedded in volcanic sedimentary rocks of the eocene,forming isolated small outcrops: khalkhab quartz monzodioritic units (sio2: ~52-57 wt %) to the northwest, neshveh granodioriticunits (sio2: ~62-71 wt %) to the northeast, and selijerd granodioritic units (sio2: ~63-69 wt %) to the southeast. the khalkhab unit iscomposed...

this research was conducted from july 1993 to june 1994 on the total population (711 workers) of a glass factory. the purpose of this study was to determine the quantitative free silica (quartz) in respiratory zone of workers in glass industry. field samples including 50 samples total dust and 37 samples respirable dust and standard simplex were collected on membrane filters using skc dust samp...

La Unión pluton (LUP) belongs to the metamorphic and igneous Sula Terrane (ST) of Central Guatemala, limited north by Motagua fault (MF) south Jocotán-Chamelecón system (J-CH-FS). The basement ST is characterized high-grade rocks belonging Las Ovejas Complex extensive low-grade San Diego phyllite, latter in tectonic contact with LUP. A combination field data, petrographic geochemical analyses a...