Floor tile installation as a source of asbestos exposure

Our plain-English summary of Floor tile installation as a source of asbestos exposure, by R.L. Murphy, B.W. Levine, F.J. al-Bazzaz, et al (The American Review of Respiratory Disease, 1971).

The study

• Authors: R.L. Murphy, B.W. Levine, F.J. al-Bazzaz, J.J. Lynch, W.A. Burgess
• Journal: The American Review of Respiratory Disease
• Published: 1971;104(4):576-80
• Cited by: 17 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 002449).

Abstract

Asphalt or vinyl-asbestos floor tile contains fifteen to twenty-five per cent asbestos, but the mineral fibers are firmly embedded in the binding material. Installation of these tiles would, therefore, seem to be an unlikely source of a hazardous dust exposure. Case reports of two installers of floor tile, one with biopsy-proved mesothelioma and another with extensive pleural calcifications are presented. Both workers had frequently sanded asphalt and vinyl tile floors prior to installation of new floor covering. An investigation of the work process revealed that under simulated conditions of work, asbestos dust concentrations as large as 1.3 fibers per ml were found in air samples passed through membrane filters worn by a person engaged in sanding vinyl asbestos. Characteristic asbestos fibers were seen in electron photomicrographs of these samples. These findings suggest that before the tile sanding procedure is performed adequate respiratory protection should be provided or alternate, available installation methods should be used.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

In plain English

This 1971 article reported on two floor tile installers who had often sanded old asphalt and vinyl tile floors before laying new floor covering. It also reported a test of the dust that sanding produces. The authors noted that such tile contains 15 to 25 per cent asbestos. The first man, aged 44, had installed tile from 1948 to 1967. A needle biopsy of his pleura showed malignant papillary mesothelioma. The second man, aged 61, had installed tile for 30 years. His chest X-ray showed extensive pleural calcification on both sides, and the authors judged he likely also had at least minimal asbestosis. In a small test room, an operator sanded vinyl tile with a belt sander for about 20 minutes. Two air samplers worn by the operator measured 1.2 and 1.3 fibers per ml. That was below the then limit of 5 fibers per ml, but the authors called these significant exposures. Electron microscopy showed fibers meeting criteria for asbestos. The authors concluded that respiratory protection or other installation methods should be used before sanding. They stated that, for the first man, exposure outside work, or mesothelioma unrelated to asbestos, could not be excluded.

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: Two case reports combined with a simulated work test measuring airborne asbestos fibers during tile sanding
• Who was studied: Two floor tile installers. One was a 44-year-old man who worked as an installer from 1948 to 1967. The other was a 61-year-old man who had installed asphalt and vinyl tile for 30 years. The patients' location is not stated beyond the authors' Boston hospital and university affiliations.
• Exposure: Sanding of asphalt and vinyl-asbestos floor tile, which the authors say contains 15 to 25 per cent asbestos (fiber type not named). In the simulation, vinyl tile was laid on plywood and sanded for about 20 minutes with a conventional belt sander using coarse grit, in a room about 10 by 12 by 7 feet with four air changes per hour.
• Main results:
  • Case 1 (44-year-old installer): a needle biopsy of the pleura showed malignant papillary mesothelioma.
  • Case 1: no asbestos bodies were seen in the pleural fluid.
  • Case 2 (61-year-old installer): the chest X-ray showed a dense plaque of calcification in the left pleural space and sheetlike pleural calcifications on the right.
  • Case 2: vital capacity was 64 per cent of predicted, with a one-second forced expiratory volume of 65 per cent of the total.
  • Case 2: the authors judged it likely that he had at least minimal pulmonary asbestosis as well as pleural disease.
  • Simulated sanding: the two personal air samples worn by the operator measured 1.2 and 1.3 fibers per ml of air.
  • These concentrations were below the threshold limit value of 5 fibers per ml. The authors said they still represented significant exposures and that the limit could be exceeded under other work conditions.
  • Airborne fibers collected during sanding and examined by electron microscopy met published criteria for asbestos.
• The authors' conclusion: The authors concluded that their findings suggest adequate respiratory protection should be provided, or alternative installation methods used, before tile is sanded.
• Limitations the authors state:
  • For the first patient, the authors could not exclude nonoccupational asbestos exposure, or mesothelioma unrelated to asbestos.
  • The authors found it difficult to assess how much underlying pulmonary asbestosis the second patient had.

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Mineral Fiber, Biopsy, Mesothelioma, Pleural Calcification, Respirator.

Related studies

• Airborne exposure during asbestos abatement of floor tile, wall plaster, and pipe insulation — J.H. Lange (2005)
• Air sampling during asbestos abatement of floor tile and mastic — J.H. Lange, K.W. Thomulka (2000)
• Impact of asbestos concentrations in floor tiles on exposure during removal — J.H. Lange (2002)
• 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 meta-analysis of airborne asbestos fiber concentrations from work with or around asbestos-containing floor tile — A.L. Perez, M.L. Nelson, et al. (2018)
• Asbestos abatement of pipe and floor tile/mastic and comparison of critical plastic barrier controls — J.H. Lange (2004)

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