Reproducibility of dust disturbance techniques during clearance sampling after asbestos removal

Our plain-English summary of Reproducibility of dust disturbance techniques during clearance sampling after asbestos removal, by J. Prentice, B. Gonsalves (The Annals of Occupational Hygiene, 1985).

The study

• Authors: J. Prentice, B. Gonsalves
• Journal: The Annals of Occupational Hygiene
• Published: 1985;29(3):435-7
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 004119).

In plain English

This short communication, from McCrone Research Associates Ltd. in London, tested whether one way of disturbing dust during clearance sampling after asbestos removal gives consistent results. Clearance sampling measures airborne fibres before a work area is released. The company's operators strike surfaces with a plastic-coated clipboard to imitate future work. The test site was a small tented lobby contaminated with amosite asbestos, most probably by airborne fibre released as bagged waste from a neighbouring amosite removal area was carried through it. The lobby was not cleaned during the study. Between 3 December 1984 and 21 December 1984, five different company representatives disturbed surfaces, with the filter always in the same place. The calculated fibre concentrations were 0.09, 0.10, 0.11, 0.10 and 0.10 fibres per ml, each plus or minus 0.02 or 0.03. All samples failed the clearance criterion of 0.01 fibres per ml or less. The authors concluded that conscientious operators can achieve a measure of reproducibility. They did not claim this is typical of all situations, because the lobby's dust was unusually even.

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: Short communication reporting repeated air sampling at a single site to check the reproducibility of a dust disturbance technique used in clearance sampling
• Who was studied: One small tented lobby in a building undergoing asbestos removal, sampled five times between 3 December 1984 and 21 December 1984 by five different McCrone Research Associates (MRA Ltd) representatives
• Exposure: Amosite asbestos contamination of the lobby, most probably from airborne fibre released when double-bagged waste from an adjacent area where amosite spray had been stripped was removed through the lobby. Surfaces were disturbed by striking them with a clipboard, and air was sampled at 3 litres per minute at about head height.
• Main results:
  • The five lobby samples gave calculated airborne fibre concentrations of 0.09 plus or minus 0.02, 0.10 plus or minus 0.03, 0.11 plus or minus 0.03, 0.10 plus or minus 0.02 and 0.10 plus or minus 0.02 fibres per ml
  • Both the lobby and the asbestos removal area failed the EH10 clearance criterion, which requires 0.01 fibres per ml or less before tenting can be removed
  • The authors interpreted the results as showing that impact disturbance of surfaces can give consistent results during clearance sampling
• The authors' conclusion: The authors concluded that conscientious operators can achieve a measure of reproducibility when disturbing potential dust sources during clearance sampling after asbestos work, while not claiming such high reproducibility is typical of all situations
• Limitations the authors state:
  • The authors did not claim that such high reproducibility is typical of all situations
  • The site was unusual: the main variable was each operator's time and energy, and dust from an airborne cloud was more uniform than the uneven deposits often found in removal areas
  • Sampling times in the lobby varied, and different operators counted different numbers of eyepiece graticule areas on the filters

Topics

Medical terms in this study, explained in our Lexicon: Clearance Air Testing.

Related studies

• Developments in dust sampling and counting techniques in the asbestos industry — S. Holmes (1965)
• Personal exposure to asbestos dust during clearance certification — S. Bailey, A. Conchie, et al. (1988)
• Kinetics of deposition and clearance of inhaled mineral dusts during chronic exposure — J.H. Vincent, A.M. Johnston, et al. (1985)
• The assessment of a modification to the acetone/triacetin clearing technique as used in the measurement of airborne asbestos dust — I.W. Furness, P.J. Reed (1985)
• Plasma lipid peroxides among workers exposed to silica or asbestos dusts — A.A. Kamal, A. Gomaa, et al. (1989)
• Vapor, dust, and smoke exposure in relation to adult-onset asthma and chronic respiratory symptoms: the Singapore Chinese Health Study — T.D. LeVan, W.P. Koh, et al. (2006)

Browse more research in The Annals of Occupational Hygiene, or return to medical research.