Asbestos exposure assessment for ceiling tile removal using glove bags in small indoor facilities

Our plain-English summary of Asbestos exposure assessment for ceiling tile removal using glove bags in small indoor facilities, by S.H. Hwang, M. Yun, D.Y. Kim, et al (Scientific Reports, 2025).

The study

• Authors: S.H. Hwang, M. Yun, D.Y. Kim, B.K. Lee, D.S. Lim
• Journal: Scientific Reports
• Published: 2025;15(1):23295
• Read it: PubMed · Publisher · Free full text

Abstract

This study aimed to evaluate the safety of small-scale asbestos dismantling and removal work, especially ceiling tile removal using glove bags (GBs), and to investigate the potential for asbestos dispersion in GBs during ceiling material removal to propose safe work practices and related regulations. Asbestos exposure assessment was conducted at five asbestos-containing ceiling tile dismantling sites nationwide. Air sampling was performed during ceiling tile removal at four points per site: near workers' respiratory tract, at the GB fixed boundary, inside the GB, and within the general work area. Phase contrast microscopy was applied to determine asbestos. The results indicated that airborne asbestos concentrations varied by region, with the highest levels detected inside the GB. Elevated concentrations were also observed near workers' respiratory tract. During ceiling tile removal, asbestos concentrations increased as the number of ceiling tiles removed rose from one to three. Proper sealing of asbestos dust to prevent leakage from the GB is essential, and removing ceiling tiles individually rather than in batches effectively reduces asbestos concentrations.

© 2025. The Author(s).

In plain English

The authors measured airborne asbestos during removal of chrysotile-containing ceiling tiles with glove bags (plastic enclosures with built-in gloves) at five small indoor sites in South Korea. Thirty air samples, counted by phase contrast microscopy, came from the worker's breathing zone, the glove bag boundary, inside the bag and the general work area. Asbestos was found at all five sites; concentrations differed significantly between sites, with averages from 0.008 fibers per cubic centimeter (f/cc) at site C to 0.117 f/cc at site A. The authors said site A exceeded the OSHA limit of 0.1 f/cc, but noted the work lasted about 30 minutes and no 8-hour time-weighted average was calculated. Averages were highest inside the glove bag (0.036 f/cc), then at the worker's breathing zone (0.029 f/cc). Removing three tiles in a row gave the highest average (0.065 f/cc), but tile-number differences were not statistically significant. Attributing leakage to poorly sealed tape, the authors concluded that good sealing and removing tiles one at a time reduce concentrations. They noted their small sample size and that their microscopy method misses very fine fibers.

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 exposure assessment (air sampling during actual asbestos ceiling tile removal work)
• Who was studied: Five small indoor sites in South Korea where asbestos-containing ceiling tiles were being dismantled: Gangnam-gu and Nowon-gu in Seoul, Yongin-si in Gyeonggi-do, Chungcheongnam-do, and Jeollabuk-do. There were 30 air samples in total. The dates of sampling are not given.
• Exposure: Airborne chrysotile asbestos released during removal of ceiling tiles with more than 1% asbestos, using glove bags. Tiles were removed one, two or three at a time. Fibers were counted by phase contrast microscopy (NIOSH Method 7400).
• Main results:
  • Airborne asbestos was detected at all five sites. Site average concentrations ranged from 0.008 f/cc at site C to 0.117 f/cc at site A.
  • Concentrations differed significantly between sites (p less than 0.05). The comparison used a rank-based test of medians (Kruskal–Wallis), not a comparison of averages.
  • The authors described the site A average as exceeding the OSHA exposure limit of 0.1 f/cc. They noted that the work there lasted only about 30 minutes, and that no 8-hour time-weighted average, which is typically used for exposure assessment, was calculated.
  • Average concentrations by sampling point were: inside the glove bag 0.036 f/cc, worker's respiratory tract (personal samples) 0.029 f/cc, indoor work area 0.015 f/cc, and glove bag boundary 0.014 f/cc. The differences between sampling points were significant (p less than 0.05).
  • By number of tiles removed, the highest average was 0.065 f/cc, when three tiles were removed consecutively. The differences by number of tiles were not statistically significant (p greater than 0.05).
  • Other averages by number of tiles were: two tiles in a row 0.014 f/cc, one tile 0.010 f/cc, and one tile followed by two tiles 0.009 f/cc.
  • When three tiles were removed consecutively, averages were 0.102 f/cc inside the glove bag and 0.076 f/cc in the worker's respiratory tract.
  • The authors found that the tape sealing the glove bag to the ceiling was not properly sealed. They attributed asbestos leaking out of the bag to this.
• The authors' conclusion: The authors concluded that safe glove bag removal of ceiling tiles requires effective sealing to prevent leakage from the bag. They also concluded that removing tiles one by one, rather than several at once, is more effective in reducing asbestos concentrations.
• Limitations the authors state:
  • The findings may not be representative because of the small sample size.
  • Comparison with other studies was difficult because there is little relevant information on glove bag ceiling tile removal.
  • Air samples were analyzed only by phase contrast microscopy, which is not sensitive to ultrafine fibers. No comparison with other methods such as transmission electron microscopy was made.

Topics

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Glovebag, Air Sampling, phase contrast microscopy (PCM).

Related studies

• Evaluation of vacuum and wet-wipe methods for removal of World Trade Center dust from indoor environments — K.M. Tang, C.G. Nace, et al. (2004)
• 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)
• Indoor airborne asbestos pollution: from the ceiling and the floor — P. Sebastien, J. Bignon, et al. (1982)
• Impact of asbestos concentrations in floor tiles on exposure during removal — J.H. Lange (2002)
• Emerging indoor pollutants — T. Salthammer (2020)

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