Development of a Real-Time Inhalable Particle Spectrometer

Details

• Personal Author:
  Anderson, Kern E.
• Description:
  Particle sizes 20 microm and larger exist in the workplace and can constitute as much as 50% or more of the inhaled dose to workers. However, instruments capable of measuring particle sizes between 20 and 100 microm are limited. For the purpose of exposure assessment, NIOSH currently specifies the 37-mm cassette, a time-integrated, mass-based method, for the measurement of inhalable particles in the workplace; this device has been shown to under-sample particles between 20 and 100 microm in size. Other inhalable samplers exist (IOM and Button sampler), but those too are mass-based instruments. Such filter-based instruments, while useful for assessing personal exposure, provide no information on the particle size distribution. All of these methods collect samples over an 8-hour period, thus temporal and spatial information on the aerosol hazard is lost. Large particles settle out quickly in air (terminal settling velocity of 100 microm particle = 0.3 m/s). Because these aerosol hazards are short-lived, a time-integrated measurement may not accurately capture these exposures. In such cases, a time-resolved instrument is required to capture the timing and magnitude of exposure. Time-resolved instruments currently exist to characterize the size distribution of aerosols in the range of 0.05 to 20 microm. There are limited time-resolved (or even time-integrated) devices that are capable of measuring the size distribution (and concentration) of particles from 20 to 100 microm. Exposure and particle deposition in the respiratory system is largely governed by particle size. There is size-dependent deposition in the head airways for particles from 10 to 50 microm. Particles 30 microm and larger are more likely to deposit in the oral cavity while 10 microm particles have the highest deposition in the tracheobronchial region. Exposure to large inhalable particles can deliver massive doses to workers and contribute substantially to the inhaled dose. For example, the mass of one 100 microm particle would be equivalent to the mass of one million 1 microm particles of equal shape/composition. Data on the burden of disease from occupational aerosol exposures shows evidence of symptomatic health effects resulting from exposure to large particles in numerous workplaces. Studies show occupational rhinitis (acute or chronic), chronic pharyngitis, chronic sinusitis, nasal cancer, chronic laryngitis and gastro-intestinal diseases occurring in many industries, which would indicate the presence of particles 30 microm and larger (because such particles are more likely to deposit in the head airways). However, we lack the tools to characterize such hazards quantitatively. This project developed a new instrument to characterize the size distribution of inhalable particles in the workplace and developed an optical detection for real-time measurement of particle size and concentration. [Description provided by NIOSH]
• Subjects:
  Aerosols Occupational Exposure Occupational Health Respiratory System Safety
• Keywords:
  Aerosol Sampling Equipment Design Exposure Assessment Inhalation Occupational Exposure Particle Aerodynamics Particle Counters Particle Size Analysis Samplers Sampling Equipment
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  Colorado ; Minnesota ; New York ; OSHA Region 2 ; OSHA Region 5 ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-13
• NIOSHTIC Number:
  nn:20062785
• NTIS Accession Number:
  PB2022-100476
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, K01-OH-010763, 2019 Nov; :1-13
• Email:
  And06109@umn.edu
• Federal Fiscal Year:
  2020
• Performing Organization:
  Colorado State University, Fort Collins
• Peer Reviewed:
  False
• Start Date:
  20150901
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20180831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:06604c85e2b5f5921d4e01eaba2fee050b90c6c59c434b76f2621d73944f8e8648659cee350cb112e21c4d0207d4d5db1e6d4c75fc8e9dfa159a6b8becb111b7
• Download URL:
  https://stacks.cdc.gov/view/cdc/219054/cdc_219054_DS1.pdf
• File Type:
  [PDF - 641.36 KB ]