rss
Occup Environ Med 2008;65:605-612 doi:10.1136/oem.2007.033712
  • Original article

Development of a fibre size-specific job-exposure matrix for airborne asbestos fibres

  1. J M Dement1,
  2. E D Kuempel2,
  3. R D Zumwalde2,
  4. R J Smith2,
  5. L T Stayner3,
  6. D Loomis4
  1. 1
    Division of Occupational and Environmental Medicine, Department of Community & Family Medicine, Duke University Medical Center, Durham, NC, USA
  2. 2
    The National Institute for Occupational Safety and Health, Education and Information Division, Cincinnati, OH, USA
  3. 3
    Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois, Chicago, IL, USA
  4. 4
    Environmental and Occupational Health, School of Public Health, University of Nevada, Reno, NV, USA
  1. Professor John M Dement, Division of Occupational and Environmental Medicine, Department of Community and Family Medicine, Duke University Medical Center, 2200 W Main Street, Suite 400, Durham, NC 27705, USA; John.Dement{at}Duke.edu
  • Accepted 2 September 2007
  • Published Online First 5 November 2007

Abstract

Objective: To develop a method for estimating fibre size-specific exposures to airborne asbestos dust for use in epidemiological investigations of exposure-response relations.

Methods: Archived membrane filter samples collected at a Charleston, South Carolina asbestos textile plant during 1964–8 were analysed by transmission electron microscopy (TEM) to determine the bivariate diameter/length distribution of airborne fibres by plant operation. The protocol used for these analyses was based on the direct transfer method published by the International Standards Organization (ISO), modified to enhance fibre size determinations, especially for long fibres. Procedures to adjust standard phase contrast microscopy (PCM) fibre concentration measures using the TEM data in a job-exposure matrix (JEM) were developed in order to estimate fibre size-specific exposures.

Results: A total of 84 airborne dust samples were used to measure diameter and length for over 18 000 fibres or fibre bundles. Consistent with previous studies, a small proportion of airborne fibres were longer than >5 μm in length, but the proportion varied considerably by plant operation (range 6.9% to 20.8%). The bivariate diameter/length distribution of airborne fibres was expressed as the proportion of fibres in 20 size-specific cells and this distribution demonstrated a relatively high degree of variability by plant operation. PCM adjustment factors also varied substantially across plant operations.

Conclusions: These data provide new information concerning the airborne fibre characteristics for a previously studied textile facility. The TEM data demonstrate that the vast majority of airborne fibres inhaled by the workers were shorter than 5 μm in length, and thus not included in the PCM-based fibre counts. The TEM data were used to develop a new fibre size-specific JEM for use in an updated cohort mortality study to investigate the role of fibre dimension in the development of asbestos-related lung diseases.

Footnotes

  • Funding: The National Institute for Occupational Safety and Health (NIOSH) supported this research (purchase order number 0000158283 and grant number R01 OH007803).

  • Competing interests: None.

This Article

  1. All Versions of this Article:
    1. oem.2007.033712v1
    2. 65/9/605 most recent

Services

  1. Request permissions

Responses

  1. Submit a response
  2. No responses published

Social bookmarking

Register for free content


Free sample
This recent issue is free to all users to allow everyone the opportunity to see the full scope and typical content of OEM.
View free sample issue >>

Free archive
The full back archive is now available for OEM. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006, back to volume 1 issue 1.
Register to access the free archive >>

Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.