Air sampling for particulates.
Authors
Glenn-RE; Craft-BF
Source
Occupational respiratory diseases. Merchant JA, Bochlecke BA, Taylor G, eds. Morgantown, WV: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 86-102, 1986 Sep; :69-82
Abstract
The current procedures employed by industrial hygienists to assess, measure, and characterize occupational exposure to potentially hazardous airborne particulates were described. The majority of particulate sampling was performed by drawing a measured volume of air through a collection device, which removed particles of interest, except for some direct reading instruments which sensed the particles without removing them. The aerodynamic properties of particles determined the fraction of particles retained in the respiratory tract, as well as the relative ease with which they could be sampled. Particles with aerodynamic size of 5 to 30 micrometers were primarily deposited in the the respiratory tract by inertia impaction. Deposition by inertia impaction occurred primarily in the nasal chamber and upper respiratory tract, and increased with increasing air velocity. Particles with aerodynamic size ranging from 0.5 to 5.0 micrometers were deposited on airway walls and alveolar surfaces through sedimentation. Particles smaller than 0.5 micrometers were primarily deposited by diffusion or Brownian motion in the alveolar region and tracheobronchial region. The standards and criteria for dust measurements in work environments were discussed. It was recommended that only the respirable fraction of dust be measured, which generally includes particles smaller than 10 micrometers. This was accomplished through the use of size selective sampling devices. Particulate samplers consisted of: air inlet, particulate separator or collection device, air flowmeter, flowrate control valve, and air mover or pump. The particulate separator was the most important component, determining the sampling efficiency and reliability of the sampler. The different techniques employed in the collection of airborne particulates and particle size analysis were reviewed. The authors conclude that the selection of the appropriate sampling and analytical instruments depends upon the character of the aerosol being sampled and the accuracy and precision required.
Keywords
Air-sampling-equipment; Particulate-sampling-methods; Workplace-studies; Sampling-methods; Occupational-diseases; Industrial-hygienists; Pulmonary-system; Humans
Editors
Merchant-JA; Bochlecke-BA; Taylor-G
Source Name
Occupational respiratory diseases
