A comparison of mass and fibre concentrations of asbestos dust in shipyard insulation processes

Our plain-English summary of A comparison of mass and fibre concentrations of asbestos dust in shipyard insulation processes, by P.G. Harries (The Annals of Occupational Hygiene, 1971).

The study

• Author: P.G. Harries
• Journal: The Annals of Occupational Hygiene
• Published: 1971;14(3):235-40
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 004297).

Abstract

Measurements have been made of the mass and fibre concentrations of dust produced during shipyard processes involving asbestos insulating materials. Comparison of the results of measuring total dust, 'respirable' dust and fibre concentration show that gravimetric measurements are not suitable for environmental monitoring in Naval Dockyards. The membrane filter technique for estimating fibre concentration is recommended for that purpose.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

In plain English

This 1971 article, part of a survey of asbestos hazards at Devonport Dockyard, a British Naval Dockyard, compared two ways of measuring asbestos dust in the air. Weighing dust on filters (total dust and the smaller 'respirable' fraction) is quicker and simpler than counting fibres collected on membrane filters. Samplers of both kinds were placed side by side during removal of sprayed crocidolite asbestos, removal of pipe lagging, and application of pipe lagging. Average fibre counts were 226.27 fibres per cubic centimetre during crocidolite removal, 152.25 during lagging removal across all compartments, and 8.88 during lagging application. Dust weight and fibre counts showed some correlation during the high-dust stripping work but very little relationship during lagging application. All measures varied widely within each process. The author reported that the measures were not related well enough for one to be accurately worked out from another. The author concluded that weighing dust was not suitable for monitoring in Naval Dockyards, where monitoring focused on areas next to asbestos work or with little dust, and recommended the fibre-counting method.

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: Comparison of air-sampling methods: gravimetric (total and 'respirable' dust mass) samplers and membrane filter fibre-count samplers run side by side for the same periods during asbestos insulation work
• Who was studied: Air samples taken during asbestos insulation processes at Devonport Dockyard (a British Naval Dockyard), in boiler rooms, engine rooms, a brick stowage space and an accumulator compartment, as part of a survey of asbestos hazards; sampling dates not stated
• Exposure: Asbestos dust from removal of sprayed crocidolite asbestos, removal of pipe lagging, and application of pipe lagging. Measured as total dust and 'respirable' dust in mg per cubic metre (six Casella type 113A MRE samplers, three with an elutriator by-pass for total dust) and as fibres per cubic centimetre (Hunt personal samplers with membrane filters; fibres 5 to 100 micrometres long with length to breadth ratio of at least 3 to 1 counted)
• Main results:
  • Removal of sprayed crocidolite asbestos: mean fibre concentration 226.27 fibres per cubic centimetre (mean total dust 17.3 and respirable dust 7.96 mg per cubic metre)
  • Removal of pipe lagging, all compartments: mean fibre concentration 152.25 fibres per cubic centimetre
  • Application of pipe lagging, all compartments: mean fibre concentration 8.88 fibres per cubic centimetre; dust concentrations were much lower than in the stripping procedures
  • Removal of sprayed crocidolite: correlation between total and respirable dust r = 0.875
  • Removal of pipe lagging: correlation of fibres per cubic centimetre with total dust r = 0.789 and with respirable dust r = 0.797
  • There was some correlation between total and respirable dust in the stripping procedures, but no such tendency during application of lagging
  • In the application processes the dust-weight measures showed very little relationship to fibre concentration; the author described an apparent negative correlation between mass and fibre number as artificial, caused by very low mass measurements in engine room samples
  • For a given respirable mass, fibres were most numerous during removal of sprayed crocidolite asbestos, fewer in the brick stowage space, and fewest in the engine and boiler rooms
  • All three measures varied very widely within each type of process, and none could be accurately derived from another
• The authors' conclusion: The author concluded that gravimetric (dust-weight) sampling is not suitable for monitoring in Naval Dockyards, where monitoring now concentrates on places next to asbestos work areas or where little dust is thought to be produced, and that the membrane filter fibre-count method remains the method of choice
• Limitations the authors state:
  • The study did not consider the problems caused by the fibrous nature of asbestos dust when using size-selective samplers for gravimetric measurement

Topics

The National Library of Medicine indexes this study under subjects our site covers: The Navy.

Medical terms in this study, explained in our Lexicon: Membrane Filter Method.

Related studies

• Asbestos dust concentrations in ship repairing: a practical approach to improving asbestos hygiene in naval dockyards — P.G. Harries (1971)
• A comparison of the results from intra-pleural and intra-peritoneal studies with those from inhalation and intratracheal tests for the assessment of pulmonary responses to inhalable dusts and fibres — G. Drummond, R. Bevan, et al. (2016)
• A comparison of parallel dust and fibre measurements of airborne chrysotile asbestos in a large mine and processing factories in the Russian Federation — E. Feletto, S.J. Schonfeld, et al. (2017)
• Asbestos dust--a community hazard? — (1969)
• Environmental measurements of total dust and fiber concentration in manufacturer and user of man-made mineral fibers — J.H. Kim, H.S. Chang, et al. (1999)
• Rate of decline of asbestos fibre concentrations in room air — J. Prentice (1985)

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