Airborne exposure concentrations during asbestos abatement of ceiling and wall plaster

Our plain-English summary of Airborne exposure concentrations during asbestos abatement of ceiling and wall plaster, by J.H. Lange, K.W. Thomulka (Bulletin of Environmental Contamination and Toxicology, 2002).

The study

• Authors: J.H. Lange, K.W. Thomulka
• Journal: Bulletin of Environmental Contamination and Toxicology
• Published: 2002;69(5):712-8
• Cited by: 12 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This study measured airborne asbestos fiber levels while workers removed painted ceiling and wall plaster containing 10-15% chrysotile asbestos. The project was in Pennsylvania in summer 2001, with three to eight workers on site per day for about 15 days. The plaster was soaked with water, and negative air machines with HEPA filters ventilated the area. Air samples were taken from workers (personal samples), 10 to 20 feet from the work (area samples), and at the air machines. Fibers were counted by phase contrast microscopy. No sample exceeded the OSHA permissible exposure limit or the 30-minute excursion limit. Average 8-hour values were 0.006 fibers per cubic centimeter (f/cc) for personal samples, 0.008 for area samples and 0.005 for machine samples. Area samples were higher than personal samples. That difference was statistically significant (p=0.02) only when results below the detection limit were counted at half that limit. The authors concluded that the likelihood of worker exposure above the limits during this work was low.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Field air-monitoring study of one asbestos abatement project, using personal (worker), area and negative air machine samples analyzed by phase contrast microscopy (NIOSH 7400 method)
• Who was studied: Abatement workers on a project in Pennsylvania in summer 2001: three to eight workers on site per day, over about 15 days, in a work area of about 5,000 square feet. Samples were 12 personal, 10 area and 10 negative air machine samples, plus 3 excursion-limit samples.
• Exposure: Removal of painted plaster, about one inch thick, reported to be 10-15% chrysotile asbestos. The plaster was troweled onto walls and attached to wire mesh on ceilings. Removal used wet methods and negative air machines with HEPA filters giving at least 4 air exchanges per hour.
• Main results:
  • No air sample exceeded the OSHA permissible exposure limit (0.1 f/cc as an 8-hour time-weighted average) or the excursion limit (1.0 f/cc over 30 minutes).
  • The arithmetic means of the 8-hour time-weighted averages were 0.006 f/cc for personal samples, 0.008 f/cc for area samples and 0.005 f/cc for negative air machine samples.
  • All three excursion-limit samples were below the detection limit, reported as less than 0.045 f/cc.
  • Using time-weighted average data, the likelihood of exceeding the permissible exposure limit was less than 5%.
  • The authors reported higher exposure levels in area samples than in personal samples. When results below the detection limit were counted at half the detection limit, personal and area samples differed significantly (p=0.02), as did personal and machine samples (p=0.047). When those results were counted at the detection limit itself, personal versus area gave p=0.07. Area versus machine samples gave p greater than 0.1 in both comparisons.
  • Four time-weighted measurements on one worker (worker A) suggested similar exposure from day to day. The authors attributed the low variability to effective control methods.
• The authors' conclusion: The authors concluded that the likelihood of worker exposure above the OSHA permissible exposure limit and excursion limit during this work was low. They also suggested that, when effective methods keep levels below standards, area samples could be included in monitoring alongside personal sampling. They called for more research on how area and personal measurements relate.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Chrysotile.

Medical terms in this study, explained in our Lexicon: Abatement.

Related studies

• Airborne exposure during asbestos abatement of floor tile, wall plaster, and pipe insulation — J.H. Lange (2005)
• Exposure to airborne asbestos during abatement of ceiling material, window caulking, floor tile and roofing material — J.H. Lange, S.L. Sites, et al. (2008)
• Exposure to airborne asbestos during abatement of ceiling material, window caulking, floor tile, and roofing material — J.H. Lange, S.L. Sites, et al. (2006)
• Personal airborne asbestos exposure levels associated with various types of abatement — J.H. Lange, K.W. Thomulka, et al. (2006)
• Airborne concentrations of asbestos in non-occupational environments — M. Corn (1994)
• Exposure to Amosite-Containing Ceiling Boards in a Public School in Switzerland: A Case Study — D. Vernez, O. Duperrex, et al. (2019)

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