Mass concentrations of airborne asbestos in the non-occupational environment--a preliminary report of U.K. measurements

Our plain-English summary of Mass concentrations of airborne asbestos in the non-occupational environment--a preliminary report of U.K. measurements, by G.J. Burdett, J.M. le Guen, A.P. Rood (The Annals of Occupational Hygiene, 1984).

The study

• Authors: G.J. Burdett, J.M. le Guen, A.P. Rood
• Journal: The Annals of Occupational Hygiene
• Published: 1984;28(1):31-8
• Cited by: 8 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. 004643).

Abstract

Airborne asbestos mass concentrations were measured at a number of sites by taking high-volume electrostatic precipitator samples and analysing by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD was shown to overestimate chrysotile levels owing to interference by non-fibrous analogues. The sites sampled included two asbestos waste tips, the immediate environments of two asbestos products factories, a decontamination site and a busy urban road junction, as well as rural and urban background. Levels appreciably above the background were recorded at industrial sites.

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

In plain English

This preliminary UK Health and Safety Executive report measured airborne asbestos in the non-occupational environment between 1977 and 1981. Sites included two asbestos waste tips, two asbestos products factories, a decontamination site, a busy road junction, and background areas. Air samples of about 1000 cubic metres were analysed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). By TEM, background averages were below 1 nanogram per cubic metre (ng/m³) for all asbestos types. The road junction averaged 2 ng/m³ of chrysotile, which the authors presumed came from braking. Inside a chrysotile factory's perimeter, TEM chrysotile averaged 35 ng/m³ in normal operation and 170 ng/m³ when 30-minute filter-cleaning periods were included. By XRD, amosite averaged 1000 ng/m³ near an amosite board plant and 1500 ng/m³ at a nearby waste tip. Another waste tip averaged 200 ng/m³ of chrysotile by TEM. XRD can overestimate chrysotile, possibly because of clay minerals or non-fibrous host rock. The authors concluded that levels above background can occur close to asbestos waste tips and manufacturing plants. They referred public health significance to an advisory committee report.

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: Environmental air-sampling survey (preliminary report) comparing three analytical methods (XRD, SEM, TEM)
• Who was studied: Non-occupational sites in the UK sampled 1977 to 1981: two asbestos waste tips, the immediate environments of two asbestos products factories (a chrysotile textile plant and an amosite board plant), a decontamination site (a disused factory), a busy urban road junction, and rural and urban background locations
• Exposure: Airborne asbestos mass concentrations (chrysotile, amosite and crocidolite), in nanograms per cubic metre, based on air samples of about 1000 cubic metres
• Main results:
  • Rural and urban background sites: average levels by TEM below 1 nanogram per cubic metre for all types of asbestos analysed
  • Busy urban road junction (Site H): average chrysotile by TEM of 2 nanograms per cubic metre, presumed by the authors to come from vehicle braking
  • Chrysotile products factory (Site A): average chrysotile by TEM inside the factory perimeter of 35 nanograms per cubic metre during normal operation, and 170 nanograms per cubic metre when 30-minute filter-cleaning periods were included in the 2-hour sampling period
  • XRD can overestimate chrysotile mass concentration compared with electron microscopy on the same samples, possibly because of interference from clay minerals or non-fibrous host rock (antigorite); at Site A, XRD overestimated chrysotile because of non-fibrous material
  • Amosite board plant (Site C) and nearby waste tip (Site D), sampled downwind: average amosite by XRD of 1000 and 1500 nanograms per cubic metre respectively, confirmed by TEM on selected samples
  • Asbestos waste tip (Site J): average chrysotile by TEM of 200 nanograms per cubic metre
  • Disused factory during amphibole asbestos removal (Site E): XRD levels were below the limit of quantification, except for two samples taken in an enclosed yard next to the working area
  • Where both methods could be compared, SEM results agreed well with TEM
• The authors' conclusion: The authors concluded that TEM results confirm asbestos fibre mass concentrations above background can occur close to asbestos waste tips and asbestos manufacturing plants. They referred the public health significance of these levels to the Advisory Committee on Asbestos's final report.
• Limitations the authors state:
  • Ultrasonic sample preparation broke up fibre bundles and split chrysotile into fibrils, which limits the usefulness of fibre count or sizing data
  • XRD does not distinguish fibres by shape, so it overestimates fibre mass when non-fibrous forms of the same mineral are present
  • SEM is limited in identifying thin fibres, and in SEM photographs all fibres not previously ruled out were assumed to be asbestos
  • In TEM, it is hard to judge the statistical significance of large fibres or fibre bundles, which can carry 5 to 100 times the mean fibre mass

Topics

Medical terms in this study, explained in our Lexicon: X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Chrysotile.

Related studies

• Airborne concentrations of asbestos in non-occupational environments — M. Corn (1994)
• The influence of external aerodymanic factors on the measurement of the airborne concentration of asbestos fibres by the membrane filter method — A.M. Johnston, A.D. Jones, et al. (1982)
• Airborne fiber concentration and size distribution of mineral fibers in area with serpentinite outcrops in Aichi prefecture, Japan — K. Sakai, N. Hisanaga, et al. (2001)
• Asbestos concentrations in public buildings - a preliminary report — J.M. le Guen, G. Burdett (1981)
• Mass transfer rates of polycyclic aromatic hydrocarbons between micron-size particles and their environment--theoretical estimates — P. Gerde, P. Scholander (1989)
• Airborne asbestos concentrations in buildings — G.J. Burdett, S.A. Jaffrey (1986)

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