Ambient Levels and Noncancer Health Effects of Inhaled Crystalline and AmorphousSilica: Health Issue Assessment

摘要

The Health assessment of silica was prepared to serve as an information sourcedocument for use by the U.S. Environmental Protection Agency. In the development of the document, the scientific literature through 1995 has been inventoried, key studies have been evaluated, and a summary and conclusions chapter has been prepared so that the noncancer toxicity and related characteristics of amorphous and crystalline silica are identified qualitatively. Information regarding sources, emissions, ambient air concentrations, and public exposure has been included to give the reader an indication of the levels of silica in the ambient air to which a population may be exposed. Concentration-response relationships observed from laboratory animal and occupational studies are discussed so that the nature of the health effects can be placed in perspective with observed environmental levels and existing particulate matter standards.