Evaluating the efficiency of an asbestos stabilizer on ceiling tiles and the characteristics of the released asbestos fibers

Our plain-English summary of Evaluating the efficiency of an asbestos stabilizer on ceiling tiles and the characteristics of the released asbestos fibers, by H.S. Jung, J.S. Cha, S. Kim, et al (Journal of Hazardous Materials, 2015).

The study

• Authors: H.S. Jung, J.S. Cha, S. Kim, W. Lee, H.J. Lim, H. Kim
• Journal: Journal of Hazardous Materials
• Published: 2015;300:378-386
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The efficiency of asbestos stabilizers and their adaptability were evaluated by investigating the characteristics of asbestos fibers released from ceiling tiles. The impact of such variables as the wind speed or vibration conditions was also studied along with the asbestos stabilizers. The concentrations of the asbestos fibers released from damaged ceiling tiles treated with stabilizers decreased by 69.5-84.4% compared with those of untreated tiles for all variables, with a statistically significant difference (p<0.001). The effects of the environmental factors on the asbestos concentrations were analyzed through a multiple regression analysis. It was determined that the surface status of the ceiling tiles and stabilizers were the main factors affecting the concentration, and the reliability of these factors was estimated as 58.3%. The lengths of the chrysotile fibers released from the damaged ceiling tiles were in the range of 0.991-79.1 μm for the untreated tiles and 3.74-35.6 μm for the tiles treated with inorganic stabilizers. It was confirmed that inorganic stabilizers are more efficient for damaged ceiling tiles. The results of this study also show that the asbestos concentrations are greatly reduced after treating damaged ceiling tiles with a stabilizer.

Copyright © 2015 Elsevier B.V. All rights reserved.

In plain English

This laboratory experiment tested whether coating asbestos-containing ceiling tiles with a stabilizer reduced airborne fiber release. The tiles, over ten years old, came from asbestos dismantling sites in Seoul, Korea. Pieces were left undamaged or were damaged by sanding. They were left untreated or coated with one of eight commercial stabilizers, four inorganic and four organic/synthetic resin. Each piece was exposed to wind (0 or 5 m/s) and vibration (0 or 30 Hz), and released fibers were measured by microscopy. For damaged tiles, fiber concentrations from treated tiles were 69.5 to 84.4% lower than from untreated tiles under every condition (p less than 0.001). For undamaged tiles, treatment made a statistically significant difference only at 5 m/s wind with no vibration. Tile damage and stabilizer use were the main factors linked to fiber concentration. Electron microscopy identified the asbestos as chrysotile. For damaged tiles at 5 m/s wind and 30 Hz vibration, treated tiles released significantly longer fibers than untreated tiles, but length differences were not significant for undamaged tiles. The authors concluded that stabilizers were very efficient at reducing fiber release, and that inorganic stabilizers were more efficient for damaged tiles.

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 air erosion experiment comparing fiber release from ceiling tiles treated and untreated with asbestos stabilizers
• Who was studied: Asbestos-containing ceiling tiles more than ten years old, collected at asbestos dismantling sites in Seoul, Korea, and cut into 200 mm by 200 mm specimens. Specimens were either undamaged or damaged by sanding.
• Exposure: Eight commercial asbestos stabilizers: two inorganic and four organic/synthetic resin from Japan, one inorganic from Australia, and one inorganic from Korea. Specimens were sampled for 1 hour at wind speeds of 0 and 5 m/s and vibration of 0 and 30 Hz. Fibers were measured by phase contrast microscopy (PCM) and transmission electron microscopy (TEM).
• Main results:
  • For damaged tiles treated with stabilizers, PCM fiber concentrations were 69.5 to 84.4% lower than for untreated damaged tiles under all test conditions (p less than 0.001).
  • Mean fiber concentrations for damaged tiles (fiber/cc), untreated (N = 6) versus treated (N = 24): 0.0441 versus 0.0069 at 0 m/s and 30 Hz; 0.0394 versus 0.0120 at 5 m/s and 0 Hz; 0.0470 versus 0.0109 at 5 m/s and 30 Hz.
  • For undamaged tiles, the difference between treated and untreated tiles was statistically significant only at a wind speed of 5 m/s with 0 Hz vibration.
  • In a multiple regression analysis, tile surface status (undamaged or damaged) and stabilizer use (treated or untreated) were the main factors affecting fiber release. The authors called the 58.3% figure 'reliability'; Table 5 gives it as an adjusted R2 of 0.5832.
  • Wind speed and vibration were not statistically significant in the multiple regression analysis.
  • For damaged tiles at 5 m/s wind and 30 Hz vibration, chrysotile fiber lengths measured by TEM ranged from 0.991 to 79.1 micrometres for untreated tiles and from 3.74 to 35.6 micrometres for tiles treated with inorganic stabilizers.
  • For damaged tiles at 5 m/s and 30 Hz, Table 6 gives geometric mean chrysotile lengths of 4.67 micrometres for untreated tiles (205 fibers), 7.43 for inorganic-treated tiles (25 fibers) and 8.03 for organic/synthetic resin-treated tiles (249 fibers). Both treated groups differed significantly from the untreated group.
  • For damaged tiles at 5 m/s and 0 Hz, the organic/synthetic resin group's geometric mean chrysotile length (5.36 micrometres) was shorter than the untreated group's (6.31). All three groups carried the same Scheffe letter.
  • No statistically significant differences in chrysotile fiber length were found for undamaged tiles under any condition, whether treated or untreated.
  • For damaged tiles, inorganic-treated and organic-treated tiles differed significantly from each other only at 5 m/s and 30 Hz: 0.0079 fiber/cc for inorganic versus 0.0139 for organic, compared with 0.0470 for untreated tiles.
  • No asbestos fibers were detected by TEM from undamaged tiles treated with organic/synthetic resins.
  • The authors stated that inorganic stabilizers were more efficient for damaged ceiling tiles.
• The authors' conclusion: The authors concluded that stabilizers applied to asbestos-containing ceiling tiles were very efficient at reducing asbestos fiber release, and that the method is adequate and applicable for maintaining asbestos-containing public buildings.
• Limitations the authors state:
  • Because of company policy, the chemical compositions of the stabilizers were not known, except partly for the Korean inorganic product.
  • PCM counts all fibrous particles. The PCM concentration for undamaged tiles at 0 m/s and 30 Hz reflects fibrous particles, not asbestos, because TEM detected no asbestos in that condition.
  • Results could not be directly compared with earlier studies because total air flow rates differed between them.

Topics

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

Related studies

• Changes in concentrations and characteristics of asbestos fibers dispersed from corrugated asbestos cement sheets due to stabilizer treatment — H.S. Jung, J. Jang, et al. (2021)
• Surface characteristics of asbestos fibers released from asbestos- cement products — J.A. Helsen, P. van de Velde, et al. (1989)
• 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)
• Characteristics of asbestos fibers in lung tissue from occupational and environmental asbestos exposure of lung cancer patients in Busan, Korea — H.S. Jung, E.K. Park, et al. (2020)
• Efficiency of sampling and analysis of asbestos fibers on filter media: implications for exposure assessment — D.A. Vallero, J.R. Kominsky, et al. (2009)

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