Evaluation of take-home exposure to asbestos from handling asbestos-contaminated worker clothing following the abrasive sawing of cement pipe

Our plain-English summary of Evaluation of take-home exposure to asbestos from handling asbestos-contaminated worker clothing following the abrasive sawing of cement pipe, by A. Abelmann, J.R. Maskrey, J.T. Lotter, et al (Inhalation Toxicology, 2017).

The study

• Authors: A. Abelmann, J.R. Maskrey, J.T. Lotter, A.M. Chapman, M.D. Nembhard, J.S. Pierce, J.M. Wilmoth, R.J. Lee, D.J. Paustenbach
• Journal: Inhalation Toxicology
• Published: 2017;29(12-14):555-566
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Although industrial uses of asbestos have declined since the 1970s, in recent years there has been a renewed interest in para-occupational ("take-home") exposure to these fibers. The aim of this study was to quantify the release of asbestos fibers, if any, during the shaking out of crocidolite- and chrysotile-contaminated clothing in a simulated at-home setting. An exposure study was conducted in which personal and area air samples were collected during the handling (i.e. shake-out) of work clothing (shirt and pants) previously worn by an operator who had cut asbestos-containing cement pipe. During eight "loading" events, the operator cut a historically representative asbestos-containing cement pipe (10% crocidolite and 25% chrysotile) using a powered abrasive saw. Subsequently, 30-minute air samples were collected during four "shake-out" events, each of which consisted of the handling of two complete sets of contaminated work clothes. Samples were analyzed in accordance with NIOSH methods 7400 and 7402. The mean phase contrast microscopy equivalent (PCME) airborne concentrations were 0.52 f/cc (SD = 0.34 f/cc) for total asbestos fibers, 0.36 f/cc (SD = 0.26 f/cc) for chrysotile and 0.17 f/cc (SD = 0.096 f/cc) for crocidolite. Based on likely estimates of the frequency of laundering activities, and assuming that the dusty clothing (1) is not blown off in the occupational setting using compressed air and (2) is not shaken out before entering the home, a family member handling the clothing could potentially have a lifetime cumulative exposure to chrysotile and crocidolite of approximately 0.20 f/cc-year and 0.096 f/cc-year, respectively.

In plain English

This was a simulation study of take-home asbestos exposure, carried out at a laboratory facility in Monroeville, Pennsylvania, in January 2017. An operator used a gasoline-powered abrasive saw to cut cement pipe containing about 25% chrysotile and 10% crocidolite. The cutting was done four times in a trench and four times above ground, while the operator wore a cotton shirt and jeans. The contaminated clothes were then shaken out indoors in a sealed chamber, two sets per event, in four 30-minute events. For the person handling the clothes, the mean asbestos concentration (PCME) was 0.52 f/cc total, 0.36 f/cc chrysotile and 0.17 f/cc crocidolite. For bystander area samples it was 0.34 f/cc total. Clothes from above-ground cutting gave significantly higher levels than clothes from trench cutting. Assuming weekly laundering for 50 days a year over 45 years, the authors estimated lifetime cumulative exposures for the clothes handler of 0.20 f/cc-years chrysotile and 0.096 f/cc-years crocidolite. The authors concluded that, under these scenarios, no increased lung cancer or mesothelioma risk would be observed in clothes handlers. They noted that only one tool, one pipe type and one clothing type were tested.

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: Simulated exposure study: work clothes were contaminated by cutting asbestos-cement pipe, then shaken out indoors while air samples were taken
• Who was studied: No disease population. Study authors acted as the saw operator and the clothes handler. The study took place at RJ Lee Group's facilities in Monroeville, Pennsylvania, over several days in January 2017. There were eight cutting events and four clothing shake-out events.
• Exposure: Asbestos-cement pipe containing about 25% chrysotile and 10% crocidolite, cut with a powered abrasive saw. The resulting fibers were released when the contaminated shirts and jeans were shaken out.
• Main results:
  • Clothes handler (personal samples, n=16): mean 30-minute PCME concentration was 0.52 f/cc total asbestos (SD 0.34), 0.36 f/cc chrysotile (SD 0.26) and 0.17 f/cc crocidolite (SD 0.096).
  • Bystander area samples (n=8): mean PCME concentration was 0.34 f/cc total asbestos (SD 0.14), 0.23 f/cc chrysotile (SD 0.10) and 0.11 f/cc crocidolite (SD 0.037).
  • Saw operator during cutting: mean 30-minute PCM concentrations were 5.2 f/cc above ground and 12.4 f/cc in the trench.
  • Clothes handler concentrations were statistically significantly higher when the clothing had been worn during above-ground cutting than when it had been worn during in-trench cutting.
  • Expressed as 8-hour time-weighted averages, the clothes handler's concentrations were 6.3% (above ground) and 6.5% (in-trench) of the operator's.
  • Estimated lifetime cumulative exposure, assuming laundry preparation 50 days a year for 45 years: 0.20 f/cc-years chrysotile and 0.096 f/cc-years crocidolite for the person preparing laundry; 0.13 f/cc-years chrysotile and 0.062 f/cc-years crocidolite for a bystander.
  • The authors compared these estimates with no-observed-adverse-effect levels proposed in an earlier publication (Pierce et al. 2016) and found them to be below those levels.
• The authors' conclusion: The authors concluded that, under the exposure scenarios they evaluated, the results support that no increased risk of asbestos-related lung cancer or mesothelioma would be observed in clothes handlers.
• Limitations the authors state:
  • Only two occupational scenarios, using one tool (an abrasive power saw), were evaluated.
  • No variations in work practices or laundry habits were tested, and only one type of pipe and one type of work clothing were used.
  • The saw had no local exhaust ventilation. The authors said the measured concentrations were therefore more likely to reflect conditions before 1972 OSHA rules.
  • The effects of historical practices for removing dust from clothing (such as compressed air or shaking clothes outdoors) were not determined.
  • Each shake-out event used two sets of clothing, which does not represent a full work week for someone who did this work daily.
  • Differences between events might reflect differing aggressiveness of shaking, which was not controlled.

Topics

Medical terms in this study, explained in our Lexicon: Take-home Exposure, Crocidolite, Chrysotile, NIOSH, phase contrast microscopy (PCM), Cumulative Exposure.

Related studies

• Evaluation of take-home exposure and risk associated with the handling of clothing contaminated with chrysotile asbestos — J. Sahmel, C.A. Barlow, et al. (2014)
• Evaluation of take home (para-occupational) exposure to asbestos and disease: a review of the literature — E.P. Donovan, B.L. Donovan, et al. (2012)
• Commentary on 'evaluation of take home (para-occupational) exposure to asbestos and disease: a review of the literature', Donovan et al.1 — D.S. Egilman, N.M. Druar (2013)
• Evaluation of the Webler-Brown model for estimating tetrachloroethylene exposure from vinyl-lined asbestos-cement pipes — L.A. Spence, A. Aschengrau, et al. (2008)
• Colorectal cancer in asbestos cement workers in Denmark — E. Raffn, E. Villadsen, et al. (1996)
• Characterizing and Communicating Risk with Exposure Reconstruction and Bayesian Analysis: Historical Locomotive Maintenance/Repair Associated with Asbestos Woven Tape Pipe Lagging — F.W. Boelter, J.D. Persky, et al. (2016)

Browse more research in Inhalation Toxicology, or return to medical research.