Area and personal airborne exposure during abatement of asbestos-containing roofing material

Our plain-English summary of Area and personal airborne exposure during abatement of asbestos-containing roofing material, by J.H. Lange, K.W. Thomulka (Bulletin of Environmental Contamination and Toxicology, 2000).

The study

• Authors: J.H. Lange, K.W. Thomulka
• Journal: Bulletin of Environmental Contamination and Toxicology
• Published: 2000;64(5):673-8
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This study measured airborne asbestos during removal of 50,000 square feet of asbestos-containing roofing from a four-story Western Pennsylvania building in summer 1999. The roofing was estimated to contain 5 to 10% chrysotile and was cut out with a power saw. Area samples and personal (breathing-zone) samples were collected. Area samples ranged from less than 0.0006 to 0.0162 fibers per cubic centimeter (f/cc), and personal samples from 0.0047 to 0.0752 f/cc. These figures were reported as concentrations that were not time-weighted averages. No single value exceeded the OSHA permissible exposure limit, and all were below it when calculated as time-weighted averages. Personal samples had statistically higher concentrations than area samples, and the two methods were not correlated. For personal samples, the authors estimated about a 35% probability that at least 5% of workers would exceed the limit, or about 30% without one outlying value. The authors concluded that exposure during this roofing abatement was low. They suggested that personal samples best represent worker exposure. They cautioned that the study had few samples, reported variation, and only one abatement project. The text does not state how many samples were taken.

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: Air-sampling (exposure measurement) study of a single asbestos roofing abatement project, comparing area and personal sampling
• Who was studied: Abatement of 50,000 square feet of roofing from one four-story building in Western Pennsylvania, summer 1999. Area samples and personal (worker breathing-zone) samples were taken about every other day over about 25 days. The number of samples and workers is not given in the available text.
• Exposure: Asbestos-containing roofing material estimated at 5 to 10% chrysotile, removed by cutting sections with a power saw
• Main results:
  • Area samples ranged from less than 0.0006 to 0.0162 f/cc. Personal samples ranged from 0.0047 to 0.0752 f/cc. The summary concentrations are labelled as non-time-weighted-average (non-TWA) values.
  • No individual area or personal value exceeded the OSHA permissible exposure limit (PEL) for airborne asbestos. When calculated as time-weighted averages, all values were below the PEL.
  • 95% confidence interval for area samples: plus or minus 0.003 (range 0.003 to 0.009 f/cc). For personal samples: plus or minus 0.011 (range 0.009 to 0.031 f/cc) without the outlier, and plus or minus 0.008 (range 0.007 to 0.028 f/cc) with the outlier.
  • Area and personal measurements were not correlated. Their concentrations were statistically different with and without the outlier.
  • Personal samples had statistically higher concentrations than area samples. The authors suggested personal samples are the best measure of occupational exposure.
  • For personal samples (treated as one homogeneous group), the estimated probability that at least 5% of workers would exceed the PEL was approximately 35%, or about 30% with the outlier removed. This is a statistical estimate, not an observed proportion of workers.
• The authors' conclusion: The authors concluded that asbestos exposure during abatement of roofing materials was low, with no single value exceeding the PEL. They suggested personal samples are the best measure of occupational exposure.
• Limitations the authors state:
  • The authors stated that the small number of samples, the reported variation, and observations from a single abatement project must temper the findings.
  • The authors noted that the counting method (PCM) does not count fibers below 5 micrometers in size.

Topics

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

Related studies

• Personal exposure during abatement of various asbestos-containing materials in the same work area — J.H. Lange, K.W. Thomulka, et al. (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. (2006)
• 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)
• A study of personal and area airborne asbestos concentrations during asbestos abatement: a statistical evaluation of fibre concentration data — J.H. Lange, P.R. Lange, et al. (1996)
• Personal airborne asbestos exposure levels associated with various types of abatement — J.H. Lange, K.W. Thomulka, et al. (2006)
• Area and personal exposure measurements during asbestos abatement of a crawl space and boiler room — J.H. Lange, M. Wang, et al. (2005)

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