矽肺供应ppt课件.pptx

A guide to working with Silica
Environmental Health, Safety and Risk Management
University of Alaska Fairbanks
December 2010
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Overview
Silica: crystalline vs. amorphous
Part I: Crystalline Silica
Health Hazards
Exposure Limits
Exposure Monitoring
Ways to Reduce Exposure
Online Resources
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Overview (cont.)
Part II: Amorphous Silica
Examples
Exposure Limits
Synthetic Vitreous Fibers
Health Hazards
Exposure Limits
Engineering Controls
Resources
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Silica
Silica (SiO2, silicon dioxide) is one of the mon minerals in the earth’s crust and is a ponent of sand, rock and mineral ores
Silica is used in the manufacturing of a variety of products from kitty litter to fiber optic cables to cosmetics and food additives
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Silica (cont.)
Silica occurs as both crystalline (structured) and non-crystalline (amorphous) forms.
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Diagram source: C/etools/silica/silicosis/
Part I: Crystalline Silica
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Silica: Crystalline
Has a diagnostic X-ray diffraction* pattern
*analytical technique which reveals information about the crystallographic structure, position, and physical properties of materials
mon types
(formed under different pressures and temperatures)
Quartz (alpha & beta)
Cristobalite
Tridymite
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Silica, Crystalline,Health Hazards,Silicosis
Silicosis is a disabling, nonreversible and sometimes fatal lung disease caused by overexposure to respirable* dust containing crystalline silica
*respirable means deposited in the gas-exchange region or deepest part of the lungs
Overexposure to dust that contains respirable crystalline silica can cause scar tissue to form in the lungs, which reduces the lungs’ ability to extract oxygen from the air
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Silicosis (cont.)
Inhalation of crystalline silica particles has been associated with other diseases, such as bronchitis, emphysema, and tuberculosis
Some studies also indicate an association with lung cancer, immunologic disorders, autoimmune diseases, renal disease and stomach and other cancers
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