Evaluation of Asbestos Exposures During Firewood-Harvesting Simulations in Libby, MT, USA-Preliminary Data

Details

• Personal Author:
  Crispen K ; Hart JF ; Spear TM ; Ward TJ ; Zolnikov TR
• Description:
  Research was conducted in order to assess potential exposure to asbestos while harvesting firewood from amphibole-contaminated trees near Libby, MT, USA. Three firewood-harvesting simulations took place in the summer and fall of 2006 in the Kootenai Forest inside the US Environmental Protection Agency (EPA) restricted zone surrounding the former W.R. Grace vermiculite mine. Another simulation was conducted near Missoula, MT, USA, which served as the control. The work practices following each simulation were consistent throughout each trial. Personal breathing zone (PBZ) asbestos concentrations were measured by phase contrast microscopy (PCM) and transmission electron microscopy (TEM). Surface wipe samples of personal protective clothing were measured by TEM. The mean (n = 12) PBZ PCM sample time-weighted average (TWA) concentration was 0.29 fibers per milliliter, standard deviation (SD = 0.54). A substantial portion (more than five fibers per sample) of non-asbestos fibers (cellulose) was reported on all PBZ samples (excluding field blanks) when analyzed by TEM. The mean (n = 12) PBZ TEM sample TWA concentration for amphibole fibers <5-um long was 0.15 fibers per milliliter (SD = 0.21) and the mean (n = 12) PBZ TEM concentration for amphibole fibers >5-um long was 0.07 fibers per milliliter (SD 5 0.08). Substantial amphibole fiber concentrations were revealed on Tyvek clothing wipe samples. The mean concentration (n = 12) was 29 826 fibers per square centimeter (SD = 37 555), with 91% (27 192 fibers per square centimeter) comprised fibers <5-mm long. There were no significant differences in PBZ and wipe sample concentrations among the tasks performed by four investigators. Each of these three simulations were consistent in demonstrating that amphibole fibers are released from tree reservoirs during firewood-harvesting activities in asbestos-contaminated areas and that the potential for exposure exists during such activities. [Description provided by NIOSH]
• Subjects:
  Asbestos Environmental Exposure Environmental Pollution Inorganic Chemicals Occupational Health Safety
• Keywords:
  Asbestos Asbestos Fibers Author Keywords: Amphibole Breathing Zone Electron Microscopy Environmental Contamination Environmental Exposure Fibers Libby Montana Tree Bark Vermiculite

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• ISSN:
  0003-4878
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Montana ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  51
• Issue:
  8
• NIOSHTIC Number:
  nn:20056165
• Citation:
  Ann Occup Hyg 2007 Nov; 51(8):717-723
• Contact Point Address:
  Julie F. Hart, Department of Safety, Health and Industrial Hygiene, Montana Tech of The University of Montana, Butte, MT, USA
• Email:
  jhart@mtech.edu
• CAS Registry Number:
  Amphibole-group minerals (CAS RN 1318-09-8)
• Federal Fiscal Year:
  2008
• Performing Organization:
  Montana Technological University
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Annals of Occupational Hygiene
• End Date:
  20290630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:87540da548829e4e95f847ccad4e17a80e8821eede9b8bccdb447546e193ed73fa927909fe285e42e1ea44cc3f395a162bcb361e7df7bb01bd5e693a1e54dfed
• Download URL:
  https://stacks.cdc.gov/view/cdc/213822/cdc_213822_DS1.pdf
• File Type:
  [PDF - 235.87 KB ]