Factors affecting aerosol sampling

Details

• Personal Author:
  Baron, Paul A.
• Description:
  The need for aerosol sampling is driven by research or regulatory needs to understand or quantify the properties of airborne particles in the workplace or ambient environments. The property of most common interest is the airborne concentration of particulate mass defined as the aerosol mass per unit volume of air, usually expressed in units of micrograms or milligrams per cubic meter. Alternatively, concentrations of other related properties such as surface area or number, or particle size distributions are also of interest in certain cases, especially where exposure to nanoparticles or ultrafine aerosols are involved. In many applications, airborne concentration of a certain chemical or analyte, usually expressed in terms of micrograms per cubic meter, is more important. Aerosol sampling is the process of collecting a representative sample of airborne particles of interest from the air environment by physically separating them from the sampled air of known volume. The degree to which the physically separated sample represents the in situ aerosol depends on the design of the physical separation device, often known as the aerosol sampler. Other factors that affect the representativeness of the particulate sample include environmental conditions (e.g., wind, temperature, humidity), particle characteristics (particularly if they are highly irregular or nonspherical), and subsequent analytical methods used for particle analysis. This chapter focuses mainly on the key characteristics of aerosol samplers that may influence the representativeness of the sampled aerosol. Direct-reading aerosol samplers are not discussed in this chapter. Most samplers use size-selective inlets that conform to certain health-based conventions. The American Conference of Governmental Industrial Hygienists (ACGIH) [Vincent 1999a; ACGIH 2015], the International Organization for Standardization (ISO) [ISO 1995], and the European Standardization Organization (Comité Europeén de Normalisation, CEN) [CEN 1993] have adopted identical particle size-selective sampling conventions for inhalable, thoracic, and respirable aerosols (Figure 1). The purpose of these conventions is to provide a scientific basis for a new generation of particle size- selective occupational exposure limits (OELs) for aerosols. Such OELs can therefore be matched to the relevant sites of aerosol deposition after inhalation into the respiratory tract, and in turn to the health effects of interest in a given exposure assessment. These sampling conventions are used throughout this manual unless otherwise specified. [Description provided by NIOSH]
• Subjects:
  Aerosols Air Pollutants, Occupational Chemistry Environmental Exposure Occupational Health Particulate Matter Risk Assessment Risk Factors Safety Workplace
• Keywords:
  Aerosol Sampling Airborne Particles Airborne Particulates Chemical Properties Environmental Exposure Equipment Design Exposure Levels Nanoparticles Particle Size Risk Factors Sampling Sampling Equipment Work Environment Workers

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• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Genre:
  Book
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DART - Division of Applied Research and Technology
• Topic:
  Workplace Safety & Health
• Location:
  North America
• NIOSHTIC Number:
  nn:20048056
• Citation:
  NIOSH manual of analytical methods, fifth edition. Ashley K, O'Connor PF, eds. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2014-151, 2016 Apr; :AE1-AE33
• Editor(s):
  Ashley K; O'Connor PF
• Federal Fiscal Year:
  2016
• Peer Reviewed:
  False
• Source Full Name:
  NIOSH manual of analytical methods, fifth edition
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:05b5a001f66c2c7fe85cb5af2a8b60b74c987e4c644caf61ed95f0bac158a6eb03b41cc65ef07d458cfc1bf6ce90252c287c7f8663491d518c33d9ba4e1b87b7
• Download URL:
  https://stacks.cdc.gov/view/cdc/202931/cdc_202931_DS1.pdf
• File Type:
  [PDF - 1.63 MB ]