Examination of Simulated Workplace Aerosols for Nanoparticle Contamination Using Transmission Electron Microscopy

Details

• Personal Author:
  Eiguren-Fernandez A ; Fung DC ; Hinds WC ; Jennerjohn N ; Kennedy NJ
• Description:
  It is uncertain which characteristics of airborne engineered nanoparticles encountered in workplace air are the best predictors of potential adverse health effects. The objective of this study is to develop a robust collection of transmission electron microscopy (TEM) techniques to measure aerosol properties of engineered nanoparticles. Many aerosol properties can be evaluated using TEM including morphology, crystal structure, surface area, particle size distribution and chemical composition. The ability of air monitoring instruments to correctly report aerosol properties can be evaluated by comparing measured properties to those found using TEM techniques. A simple versatile electrospray aerosol generator is used to aerosolize single-walled carbon nanotubes and quantum dots. Since those who work with nanoparticles also encounter other airborne pollutants, we aerosolize these nanoparticles with varying amounts of two NIST SRMs, urban dust and diesel particulate matter. Altering the proportion of pollutant to nanomaterial allows the simulation of atmospheres containing nanoparticles and the evaluation of limits of detection of aerosol monitoring instruments and techniques. Numerous TEM images have been obtained. The TEM methods used permit quantitation of engineered nanoparticle concentration among the airborne particulates deposited onto TEM grids. Samples were also taken from two campus research labs, one where carbon nanotubes are in heavy use, and one where quantum dots are synthesized. These two labs serve as test sites for the evaluation of instruments and techniques that may prove efficacious in quantifying worker exposure to airborne nanomaterials in the industrial setting. There is a long history of using microscopy in occupational health studies. Phase-contrast microscopy (PCM) is used to quantify asbestos exposure, and TEM complements PCM using selected area electron diffraction (SAED) for identification of crystal structure and energy-dispersive x-ray (EDX) for chemical analysis. UCLA is home to several TEMs in its Electron Imaging Center for NanoMachines (EICN) capable of performing SAED and EDX, as well as three-dimensional electron tomography. Progress to date in establishing this TEM performance baseline at the EICN for the evaluation of instrument performance will be reported. [Description provided by NIOSH]
• Subjects:
  Aerosols Air Pollutants, Occupational Environmental Monitoring Occupational Exposure Occupational Health Safety
• Keywords:
  Aerosol Particles Air Monitoring Air Pollutants Electron Microscopy Nanoparticles Occupational Exposure Single-walled Carbon Nanotubes SWCNT
• Publisher:
  American Association for Aerosol Research
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  California ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• NIOSHTIC Number:
  nn:20058529
• Citation:
  Proceedings of the AAAR 27th Annual Conference, October 20-24, 2008, Orlando, Florida. Mount Laurel, NJ: American Association for Aerosol Research, 2008 Oct; :7C.06
• CAS Registry Number:
  Carbon nanotubes (CAS RN 308068-56-6)
• Federal Fiscal Year:
  2009
• Performing Organization:
  University of California Los Angeles
• Peer Reviewed:
  False
• Start Date:
  20050701
• Source Full Name:
  Proceedings of the AAAR 27th Annual Conference, October 20-24, 2008, Orlando, Florida
• End Date:
  20270630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:3b4309f32ce017399bcc8608047f3448cc98dbc1c7f7e555fabf8d1e4437bf67efaf25a7600bd98a19b03bc2d6445619fe25cdd6af09409d2518d7e0f0726304
• Download URL:
  https://stacks.cdc.gov/view/cdc/221604/cdc_221604_DS1.pdf
• File Type:
  [PDF - 363.35 KB ]