Ambient air concentrations of asbestos fibers near the town of Asbestos, Québec

Our plain-English summary of Ambient air concentrations of asbestos fibers near the town of Asbestos, Québec, by B. Singh, J.P. Thouez (Environmental Research, 1985).

The study

• Authors: B. Singh, J.P. Thouez
• Journal: Environmental Research
• Published: 1985;36(1):144-59
• Cited by: 4 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. 004743).

Abstract

Ambient air concentrations of asbestos fibers were measured during the period June 20 to August 12, 1980, at three locations; Danville, Asbestos, and Wottenville in the eastern townships of Quebec. Measurements were done with low-volume samplers and measurement periods extended from 3 to 13 days. Fiber counts were done by means of electron microscopy. Results indicate that overall fiber concentrations are related to atmospheric stability and to the direction of the prevailing wind with respect to the source of emission.

In plain English

This was an outdoor air-monitoring study. It did not examine anyone's health. The authors measured asbestos fibers in the air from 20 June to 12 August 1980 at three places near the open-pit Jeffrey mine in Quebec. These were the town of Asbestos, at the eastern edge of the mining site; Danville, about 3 km west; and Wottenville, a rural town about 11 km east-south-east. The authors described chrysotile as the region's dominant fiber. Fibers were counted by electron microscopy and expressed as nanograms per cubic metre. Levels were generally highest at Asbestos, reaching 269.302 ng per cubic metre for 23 to 27 June. Wottenville's highest was 128.515, for 28 to 30 July. Near the mine, wind direction mattered most: westerly winds brought the highest levels at Asbestos, and easterly winds did so at Danville. At Wottenville, atmospheric stability and wind speed seemed more important. The authors concluded that places farther from mines sometimes have concentrations as high as places beside them, and wrote that this implies health effects there too. They had too few data points for full statistical tests, and some data were lost when samplers broke down.

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-monitoring (field measurement) study. Low-volume air samplers were used, fibers were counted by transmission electron microscopy, and counts were converted to mass concentrations (ng per cubic metre).
• Who was studied: Outdoor air at three sites near the open-pit Jeffrey mine, Quebec, from 20 June to 12 August 1980: the town of Asbestos (eastern edge of the mining site; sampler on the municipal building roof), Danville (about 3 km west of the mine and tailing disposal site) and Wottenville (a rural town about 11 km east-south-east of the mining site).
• Exposure: Airborne asbestos fibers from local mining, milling and disposal sites. The authors describe the dominant fiber in the eastern townships of Quebec as chrysotile, and their mass calculation used the density of chrysotile.
• Main results:
  • For the periods with data, the highest fiber concentrations were at Asbestos. The authors attributed this mainly to wind direction relative to the source and to proximity to the source.
  • The highest value recorded at Asbestos was 269.302 ng per cubic metre, for the 23 to 27 June 1980 sampling period (Table 5; Table 2 gives 269).
  • The highest value recorded at Wottenville was 128.515 ng per cubic metre, for the 28 to 30 July 1980 sampling period (Table 5; Table 3 gives 129).
  • At Asbestos, wind direction was the dominant factor. Westerly winds were associated with the highest concentrations and easterly winds with the lowest.
  • At Danville, easterly winds were associated with the highest concentrations.
  • At Danville, the lowest concentrations occurred under relatively unstable (well-mixed) conditions and the highest under more stable, neutral conditions.
  • At Wottenville, the highest concentrations occurred with south-easterly winds, which came from a source region other than the mining area.
  • At more distant stations such as Wottenville, atmospheric stability and wind speed appeared more critical than wind direction in determining fiber concentrations.
  • Concentrations varied widely over time at every site. The authors related these variations mainly to windiness and turbulence.
• The authors' conclusion: The authors concluded that areas relatively far from mining sites, such as Wottenville, sometimes have airborne asbestos concentrations as high as areas bordering the mines. They wrote that this implies those sites are also subject to the harmful health effects of asbestos air pollution. The study itself measured only air concentrations.
• Limitations the authors state:
  • There were too few data points to carry out exhaustive statistical tests of the authors' hypotheses.
  • Because of instrument malfunction, data were missing for Asbestos from 4 July onward and for Wottenville from 27 June to 4 July.
  • One sampling period lasted 13 days instead of the usual 2 to 6 days because no operator was present.

Mines named here

Asbestos mines this study is about. Each mine's page says who ran it, when it worked, and what it produced.

• Jeffrey mine, Asbestos, Quebec

All asbestos mines

Topics

Medical terms in this study, explained in our Lexicon: Eastern Townships.

Related studies

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• Exploratory sampling of asbestos in residences near Thetford Mines: the public health threat in Quebec — M. Marier, W. Charney, et al. (2007)
• Monitoring of airborne asbestos fibers in an urban ambient air of Shahryar City, Iran: levels, spatial distribution, seasonal variations, and health risk assessment — F. Taghizadeh, A.J. Jafari, et al. (2019)
• Reconstruction of a century of airborne asbestos concentrations — J.S. Webber, K.W. Jackson, et al. (2004)
• Response to Letter to the Editor Regarding "Ambient Asbestos Fiber Concentrations and Long-Term Trends in Pleural Mesothelioma Incidence Between Urban and Rural Areas in the United States (1973-2012)" by Finkelstein — K.A. Keeton, M.E. Glynn, et al. (2018)
• Letter Concerning: Glynn ME, Keeton KA, Gaffney SH, Sahmel J. Ambient Asbestos Fiber Concentrations and Long-Term Trends in Pleural Mesothelioma Incidence Between Urban and Rural Areas in the United States (1973-2012). Risk Analysis 2018;38(3):454-471 — M.M. Finkelstein (2018)

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