Vinyl-Asbestos Floor Risk Exposure in Three Different Simulations

Our plain-English summary of Vinyl-Asbestos Floor Risk Exposure in Three Different Simulations, by L. Zichella, F. Baudana, G. Zanetti, et al (International Journal of Environmental Research and Public Health, 2021).

The study

• Authors: L. Zichella, F. Baudana, G. Zanetti, P. Marini
• Journal: International Journal of Environmental Research and Public Health
• Published: 2021;18(4)
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Vinyl floors are widely used in public areas for their low cost and easy cleaning. From 1960 to 1980, asbestos was often added to improve vinyl floor performances. The Italian Ministerial Decree (M.D.) 06/09/94 indicates asbestos vinyl tiles as non-friable materials and, therefore, few dangerous to human health. This work aims to check through three different experimental tests if asbestos floor tiles, after decades of use, maintain their characteristics of compactness and non-friability. The effect of a small stone fragment stuck in the sole of rubber shoes was reproduced by striking the vinyl floor with a crampon. A vinyl tile was broken into smaller pieces with the aid of pliers to simulate what normally happens when workers replace the floors or sample it to verify the presence of asbestos. The third test reproduced the abrasion of the tile surface due to the dragging of furniture or heavy materials or sand grains that remain attached to the soles of shoes. The tests were carried out in safe conditions, working under an extractor hood with a glove box. Airborne sampling in the hood obtained the concentration of asbestos fibers produced in each test. The simulation tests performed confirms the possible release of fibers if the vinyl tiles are cut, abraded or perforated, as indicated by the Italian M.D.

In plain English

This laboratory study tested whether vinyl floor tiles containing chrysotile asbestos, after years of use, release airborne fibers when handled. The authors used two tile types from public buildings: a flexible green tile (F) laid in the 1990s and a more rigid black tile (R) laid in the 1980s. Inside a closed glove-box hood, in dry conditions, they broke tiles with multigrip pliers, struck and dragged a steel crampon on them 100 times to mimic walking, and sanded them with fine and coarse sandpaper. Fibers in air samples were counted by scanning electron microscopy. Plier breakage gave 3.05 fibers/liter for R and 1.53 for F. Only R exceeded the 2 fibers/liter limit the authors applied. The crampon test produced no powder and 0 fibers/liter for both tiles. Sanding gave 12.97 (F) and 24.42 (R) fibers/liter with fine paper, and 9.16 (F) and 7.63 (R) with coarse paper. All of these sanding results were above the limits. The authors concluded that fibers are released only when the tiles are abraded, perforated or cut, not in normal use. They noted that 100 crampon strikes may underestimate long-term wear from foot traffic.

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: Laboratory simulation experiment on two vinyl-asbestos floor tile samples, with airborne fiber sampling analyzed by SEM/EDS
• Who was studied: Two types of vinyl floor tile taken from public buildings (location of the buildings not stated): sample F, green and flexible, laid in the 1990s; sample R, black and more rigid, laid in the 1980s
• Exposure: Chrysotile-containing vinyl tiles (asbestos content taken as 10 to 25% per the Italian M.D. 6/9/94). Three tests, all done dry inside a confined hood: multigrip plier breakage for 15 minutes; 100 impact-and-drag strikes with a steel crampon in ten minutes; and abrasion for 5 minutes with fine (P120) and coarse (P40) sandpaper. Air was sampled at 8 L/min for 180 minutes (1440 L) and analyzed by SEM/EDS.
• Main results:
  • Multigrip plier breakage: airborne asbestos fiber concentration was 3.05 fibers/liter for sample R and 1.53 fibers/liter for sample F
  • In the plier breakage test, only sample R exceeded the limit of 2 fibers/liter
  • Crampon impact-and-drag test: 0 fibers/liter for both samples, and no powder was produced
  • Fine-grained sandpaper abrasion: 12.97 fibers/liter for sample F and 24.42 fibers/liter for sample R
  • Coarse-grained sandpaper abrasion: 9.16 fibers/liter for sample F and 7.63 fibers/liter for sample R
  • Abrasion with both sandpapers produced fiber release above the limits for both samples
  • Abrasion powder: with coarse sandpaper, 4.4 g powder containing 0.4 g asbestos for F and 6.2 g containing 0.7 g for R; with fine sandpaper, 4 g containing 0.4 g for F and 5.3 g containing 0.6 g for R. The authors stated that this puts the chrysotile content between 10% and 12%.
  • Overall, the authors reported worse results for sample R than for sample F, which they attributed to R's rigidity and ageing
• The authors' conclusion: The authors concluded that, as the Italian Ministerial Decree states, vinyl-asbestos flooring releases fibers only if abraded, perforated or cut, and not during normal use, even after more than 30 years in place. They also concluded that breaking tiles gives a limited release that can exceed the limits, especially for rigid, old and worn floors.
• Limitations the authors state:
  • The 100 crampon strikes could underestimate the wear caused by foot traffic over time
  • The quantity of chrysotile was hard to evaluate because it is unevenly distributed in the tiles, so the authors used the 10 to 25% range from the Decree
  • Short asbestos fibers (under 5 microns long) were not counted, because the regulation does not consider them dangerous to health

Topics

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

Related studies

• Indoor airborne asbestos pollution: from the ceiling and the floor — P. Sebastien, J. Bignon, et al. (1982)
• 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)
• 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)
• 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. (2006)
• Chrysotile asbestos exposure associated with removal of automobile exhaust systems (ca. 1945-1975) by mechanics: results of a simulation study — D.J. Paustenbach, A.K. Madl, et al. (2006)

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