In-Cabin Commuter Exposure to Ultrafine Particles on Los Angeles Freeways

Details

• Personal Author:
  Eiguren-Fernandez A ; Hinds WC ; Miguel AH ; Zhu Y
• Description:
  Worldwide people are exposed to toxic ultrafine particles (UFP, with diameters (dp) less than 100 nm) and nanoparticles (NP, dp < 50 nm) under a variety of circumstances. To date, very limited information is available on human exposure to freshly emitted UFP and NP while traveling on major roads and freeways. We report in-cabin and outdoor measurements of particle number concentration and size distributions while driving three vehicles on Los Angeles freeways. Particle number concentrations and size distributions were measured under different vehicle ventilation settings. When the circulation fan was set to on, with substantial external air intake, outside changes in particle counts caused corresponding in-cabin changes approximately 30-60 s later, indicating an maximal air exchange rate of about 120-60 h-1. Maximum in-cabin protection (approx. 85%) was obtained when both fan and recirculation were on. In-cabin and outdoor particle size distributions in the 7.9-217 nm range were observed to be mostly bimodal, with the primary peak occurring at 10-30 nm and the secondary at 50-70 nm. The vehicle's manufacture-installed particle filter offered an in-cabin protection of about 50% for particles in the 7-40 nm size range and 20-30% for particles in the 40 to approx. 200 nm size range. For an hour daily commute exposure, the in-vehicle microenvironment contributes approximately 10-50% of people's daily exposure to UFP from traffic. [Description provided by NIOSH]
• Subjects:
  Air Pollution Occupational Health Particulate Matter Safety Transportation Ventilation
• Keywords:
  Air Pollution Automotive Emissions Filters Particle Aerodynamics Particulates Ultrafine Particles
• ISSN:
  0013-936X
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  California ; OSHA Region 6 ; OSHA Region 9 ; Texas
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  41
• Issue:
  7
• NIOSHTIC Number:
  nn:20058399
• Citation:
  Environ Sci Technol 2007 Apr; 41(7):2138-2145
• Contact Point Address:
  Antonio H. Miguel, Institute of the Environment, and Department of Environmental Health Sciences, University of California Los Angeles, 650 Charles E. Young Drive, Los Angeles, California 90095
• Email:
  ahmiguel@ucla.edu
• Federal Fiscal Year:
  2007
• Performing Organization:
  University of California Los Angeles
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Environmental Science and Technology
• End Date:
  20270630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a13506028ca859028fb9bb5b95f9e6909e25318f2368bdffeba9ad0445b189766b210242814c3b8fd351fd10467e4b9a114549ca0f6bb0623ee53dd73c713937
• Download URL:
  https://stacks.cdc.gov/view/cdc/221505/cdc_221505_DS1.pdf
• File Type:
  [PDF - 761.79 KB ]