Automated Aerosolization, Dispersion, and Concentration Control of Silica Powder for Use in Inhalation Exposure Studies

Details

• Personal Author:
  Afshari A ; Chen B ; Frazer D ; McKinney W
• Description:
  Inhalation exposure systems are necessary tools for determining the dose response relationship of inhaled toxicants under a variety of exposure conditions. The objective of this project was to develop an automated computer controlled system to expose small laboratory animals to precise concentrations of uniformly dispersed airborne silica particles. An acoustical aerosol generator was developed which was capable of suspending a respirable fraction of particles from bulk powder [Mckinney et al. Inhal Toxicol 21(12):1053-1061]. The aerosolized silica output from the generator was introduced into the throat of a venturi tube. The high velocity air stream within the ventui tube further broke up and dispersed the aerosolized powder. This air was then used to expose small laboratory animals to constant aerosol concentrations, up to 20 mg/m3, for durations lasting as long as 8 hours. Particle distribution and morphology of the silica aerosol delivered to the exposure chamber were measured to verify that a fully dispersed and respirable aerosol was being delivered to the animals' breathing space. The inhalation exposure system utilized a combination of air flow controllers, particle monitors, data acquisition devices, and custom software with automatic feedback control to achieve constant and repeatable exposure chamber temperature, relative humidity, pressure, aerosol mass concentration, and particle size distribution. The automatic control algorithm was capable of delivering median aerosol concentrations to within +/- 0.2 mg/m3 of a user selected target value during inhalation exposures lasting from 4 to 8 hours. The system was capable of reaching 95% of the target value in less than 15 minutes during the start up phase of an inhalation exposure. This exposure system provides a highly automated tool for exposing small laboratory animals to precise concentrations of uniformly dispersed airborne silica particles. [Description provided by NIOSH]
• Subjects:
  Aerosols Air Pollutants, Occupational Cytotoxins Environmental Monitoring Hazardous Substances Hypersensitivity Irritants Laboratories Lung Lung Diseases Occupational Health Particulate Matter Respiratory Hypersensitivity Respiratory System Respiratory Tract Diseases Safety Silicon Dioxide

  More +
• Keywords:
  Aerosol-particles Airborne-particles Biological-effects Cell-biology Cellular-reactions Chemical-hypersensitivity Cytotoxic-effects Exposure-assessment Exposure-levels Exposure-methods Inhalation-studies Laboratory-animals Laboratory-testing Lung-disorders Lung-irritants Particle-aerodynamics Particulates Pulmonary-disorders Pulmonary-system Pulmonary-system-disorders Respiratory-hypersensitivity Respiratory-irritants Respiratory-system-disorders Silica-dusts Toxins

  More +
• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  OSHA Region 3 ; OSHA Region 8 ; Utah ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  114
• Issue:
  1
• NIOSHTIC Number:
  nn:20036633
• Citation:
  Toxicologist 2010 Mar; 114(1):317
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7)
• Federal Fiscal Year:
  2010
• NORA Priority Area:
  Construction ; Manufacturing
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 49th Annual Meeting and ToxExpo, March 7-11, 2010, Salt Lake City, Utah
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:03a1422532f67639468ec2159a0fcd733c7995031ee9f141219e7c0997b4c3ec487908a92c40029d47c63f190bb1349a4667765bdac76fadb563ba13c796e07d
• Download URL:
  https://stacks.cdc.gov/view/cdc/187979/cdc_187979_DS1.pdf
• File Type:
  [PDF - 726.12 KB ]