Estimation of Exposure to Asbestos-Cement Dust on Building Sites

Our plain-English summary of Estimation of Exposure to Asbestos-Cement Dust on Building Sites, by K. Rödelsperger, H.-J. Woitowitz, H.G. Krieger (1980).

The study

• Authors: K. Rödelsperger, H.-J. Woitowitz, H.G. Krieger
• Published: BIOLOGICAL EFFECTS OF MINERAL FIBRES (J.C. WAGNER, EDITOR), LYON: IARC SCIENTIFIC PUBLICATIONS, VOLUME 30, PP. 845-853 (1980)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

The authors measured dust on about 40 building sites in the Federal Republic of Germany where asbestos-cement products were handled. They also took occupational histories from 61 roofers out of a planned 400. Most measurements were made during roofing with corrugated asbestos-cement sheets. High fine-dust levels occurred only during cutting with a grinding machine, which took a mean of 5.7% of the measured time. The fine dust was about 10% chrysotile. In personal samples, cutters' estimated mean fine dust was 2.2 mg/m³ (confidence interval 1.3 to 8.9) when cutting in stacks and 1.82 mg/m³ (0.85 to 9.81) when cutting on roofs. Near the machine, peaks exceeded 100 fibres/ml longer than 5 µm. For roofing with corrugated sheets, counting both cutters and bystanders, the daily means were estimated at 0.6 fibres/ml longer than 5 µm and about 0.11 mg/m³ of chrysotile fine dust. For use of corrugated sheets, cumulative exposure had a median of 0.21 year-mg/m³, and the mean cumulative fibre exposure was 1.6 plus or minus 1.6 year-fibres/ml. The authors concluded this was low compared with past asbestos-industry exposure, but that a follow-up study seemed necessary. They noted the dust measurements were incomplete.

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: cross-sectional exposure study: dust measurements on building sites combined with occupational histories of workers
• Who was studied: about 40 building sites in the Federal Republic of Germany; 61 roofers examined so far, out of a planned cohort of 400 workers who had handled asbestos-cement products for eight years or more; no study dates given
• Exposure: asbestos-cement fine dust during roofing, siding, installation of ventilation shafts and fire insulation; most measurements were made during roofing with corrugated asbestos-cement sheets, where high fine-dust concentrations occurred only while a grinding machine was used; the fine dust was about 10% chrysotile
• Main results:
  • Cutting took a mean of 5.7% of the measured working time on building sites; from the roofers' histories, cutting time was estimated at 16% of an eight-hour shift
  • At open-air cutting locations on type 1 sites, measured fine-dust concentrations ranged from 0.1 to 1.35 mg/m³ by static sampling and from 0.13 to 7.6 mg/m³ by personal sampling
  • Cutting in stacks (type 1 sites), personal sampling: estimated mean fine-dust concentration 2.2 mg/m³, confidence interval 1.3 to 8.9
  • Cutting on roofs (type 2 sites), personal sampling: estimated mean fine-dust concentration 1.82 mg/m³, confidence interval 0.85 to 9.81
  • For roofing with corrugated sheets, once cutters and bystanders were both taken into account, mean exposure to chrysotile fine dust was about 0.11 mg/m³ for both types of building site
  • Peak concentrations of more than 100 fibres/ml longer than 5 µm, or about 80 mg/m³ of fine dust, were observed near the grinding machine
  • Close to the worker's head during cutting, fibre concentrations were 0.6 to 41 fibres/ml longer than 5 µm, with a mean of 20 fibres/ml over nine measurements. The daily mean for workers roofing with corrugated sheets was estimated at 0.6 fibres/ml for both types of site
  • Fibres longer than 5 µm made up 4% to 60% of free fibres (median 25%); mean fibre lengths ranged from 1 to 5 µm and diameters from 0.1 to 0.4 µm
  • Among the roofers, roofing with corrugated sheets was done on up to 125 days per year (median 34 days per year)
  • For use of corrugated sheets, the median cumulative asbestos fine-dust exposure was 0.21 year-mg/m³. With a mean exposure duration of 16 years, mean yearly exposure was roughly 20% of the German limit value of 0.1 mg/m³
  • The mean cumulative fibre exposure was 1.6 plus or minus 1.6 year-fibres/ml. The authors said this corresponds to only 0.8 years at the limit value of 2 fibres/ml longer than 5 µm
• The authors' conclusion: The authors concluded that this cumulative exposure is low compared with past exposure in the asbestos industry, but that an epidemiological follow-up study of this large population of roofers would seem necessary
• Limitations the authors state:
  • The dust measurements were not yet complete
  • The cross-sectional study would need to be extended to a longitudinal study to assess tumour risk

Topics

Medical terms in this study, explained in our Lexicon: Asbestos-Cement, Chrysotile, Personal Breathing Zone Sample, confidence interval, Cumulative Exposure.

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