Estimation of the Human Extrathoracic Deposition Fraction of Inhaled Particles Using a Polyurethane Foam Collection Substrate in an IOM Sampler.

Int J Environ Res Public Health

Rocky Mountain Center for Occupational & Environmental Health, Department of Family & Preventive Medicine, University of Utah, Salt Lake City, UT 84108, USA.

Published: March 2016

AI Article Synopsis

  • Extrathoracic deposition of inhaled particles is a significant exposure pathway for hazardous materials, particularly in the head and throat areas.
  • New ISO standards (ISO 13138) focus on sampling conventions for measuring how particles deposit in the upper respiratory tract, specifically the anterior and posterior nasal passages.
  • This study tested polyurethane foam in an aerosol sampler, finding that it effectively estimates extrathoracic particle deposition for various sizes of aluminum oxide aerosols using a rotating mannequin setup in a wind tunnel.

Article Abstract

Extrathoracic deposition of inhaled particles (i.e., in the head and throat) is an important exposure route for many hazardous materials. Current best practices for exposure assessment of aerosols in the workplace involve particle size selective sampling methods based on particle penetration into the human respiratory tract (i.e., inhalable or respirable sampling). However, the International Organization for Standardization (ISO) has recently adopted particle deposition sampling conventions (ISO 13138), including conventions for extrathoracic (ET) deposition into the anterior nasal passage (ET₁) and the posterior nasal and oral passages (ET₂). For this study, polyurethane foam was used as a collection substrate inside an inhalable aerosol sampler to provide an estimate of extrathoracic particle deposition. Aerosols of fused aluminum oxide (five sizes, 4.9 µm-44.3 µm) were used as a test dust in a low speed (0.2 m/s) wind tunnel. Samplers were placed on a rotating mannequin inside the wind tunnel to simulate orientation-averaged personal sampling. Collection efficiency data for the foam insert matched well to the extrathoracic deposition convention for the particle sizes tested. The concept of using a foam insert to match a particle deposition sampling convention was explored in this study and shows promise for future use as a sampling device.

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Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808955PMC
http://dx.doi.org/10.3390/ijerph13030292DOI Listing

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