Emission of airborne fibers from mechanically impacted asbestos-cement sheets and concentration of fibrous aerosol in the home environment in Upper Silesia, Poland

Our plain-English summary of Emission of airborne fibers from mechanically impacted asbestos-cement sheets and concentration of fibrous aerosol in the home environment in Upper Silesia, Poland, by J.S. Pastuszka (Journal of Hazardous Materials, 2009).

The study

• Author: J.S. Pastuszka
• Journal: Journal of Hazardous Materials
• Published: 2009;162(2-3):1171-7
• Cited by: 12 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The emission rate ((S)) of fibers released from asbestos-cement plates due to mechanical impact was determined experimentally. The emission rate has been defined as a number of fibers (F) emitted from a unit area (m(2)) due to the unit impact energy (J). For fiber longer than 5 microm the obtained surface emission factor for asbestos-cement slabs slightly increased with deteriorating surface, changing from 2.7 x 10(3) F/(m(2)J) for samples with a very good surface to 6.9 x 10(3) F/(m(2)J) for the sample with worn surface (in the SI system the emission rate unit should be (m(-2)J(-1))). The emission rate for short fibers (L < or = 5 microm) was little higher compared with emission of long fibers for all studied asbestos materials. The averaged emission rate for all studied samples was about 5000 and 6000 of long and short fibers, respectively, emitted per square meter (because of the impact energy equal to 1J). The dominating population of emitted fibers ranged from 2 to around 8 microm in length. The second part of this work constitutes the report on the concentration of airborne respirable fibers, and their length distribution in two different groups of homes in Upper Silesia, Poland. Mean concentration level of the respirable fibers, longer than 5 microm, was found to be 850 F/m(3) (according to the SI system the fiber concentration unit is (m(-3))) in the buildings covered with asbestos-cement sheets and 280 F/m(3) in the homes without asbestos-containing facades, located away from other asbestos sources. Although the laboratory and field measurements have been made by using the MIE Laser Fiber Monitor FM-7400 only, the obtained results indicate that the outdoor asbestos-cement building facades are significant sources of airborne fibers inside the dwellings in Upper Silesian towns.

In plain English

In a laboratory, the author dropped weights onto six asbestos-cement sheet samples aged 15 to 35 years, detached from buildings (one from a roof), at impact energies of 0.4 and 1.0 joules, and counted released fibers with a laser monitor. Averaged over the six samples, 5.1 × 10^3 fibers longer than 5 micrometres and 5.7 × 10^3 shorter fibers were released per square metre per joule. For long fibers, the rate rose from 2.7 × 10^3 for samples with very good surfaces to 6.9 × 10^3 for the one worn sample, and was not strongly related to age. In 24-hour indoor measurements in four Upper Silesian towns, 25 homes in buildings covered with asbestos-cement sheets averaged 850 fibers longer than 5 micrometres per cubic metre, against 280 in 20 reference homes. The author concluded that asbestos-cement facades are significant sources of indoor airborne fibers. The author noted the laser monitor was the main instrument, that it agreed weakly with phase contrast microscopy in parallel tests in three homes and two outdoor points, and that electron microscopy studies are needed to confirm the results.

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: Laboratory experiment measuring fiber release from mechanically impacted asbestos-cement sheets, combined with an indoor air measurement survey comparing two groups of homes
• Who was studied: Six asbestos-cement samples, 15 to 35 years old, detached from buildings, mostly in Sosnowiec. The text describes them as facade samples, but the sample table lists one (sample 2) as coming from the roof of an apartment house. Indoor air was measured in 45 homes in Katowice, Chorzów, Sosnowiec and Bytom, Upper Silesia, Poland: 25 in buildings covered with asbestos-cement sheets and 20 reference homes without them. Dates of measurement are not given.
• Exposure: In the laboratory, asbestos-cement sheets were struck by falling weights at impact energies of 0.4 and 1.0 J. The field part compared homes in buildings covered with asbestos-cement sheets with homes without them. The asbestos fiber type is not specified.
• Main results:
  • Averaged over the six samples, the emission rate was 5.1 × 10^3 fibers per square metre per joule for long fibers (longer than 5 micrometres) and 5.7 × 10^3 for short fibers (5 micrometres or shorter).
  • For long fibers, the emission rate rose from 2.7 × 10^3 fibers per square metre per joule for samples with a very good surface to 6.9 × 10^3 for the one sample with a worn surface.
  • The emission rate of individual samples was not strongly related to slab age but depended on surface quality.
  • Sample No. 5 had a long-fiber emission rate of 3.1 × 10^3 per square metre per joule with its originally very good surface. After it was mechanically broken, the rate rose to 2.0 × 10^4.
  • Fibers emitted in the laboratory experiments had a peak in the 4 to 5 micrometre length range.
  • Mean concentration of fibers longer than 5 micrometres was 850 per cubic metre in homes in buildings covered with asbestos-cement sheets (Group I). This was three times the 280 per cubic metre in control homes (Group II).
  • In the 25 Group I homes, fibers longer than 5 micrometres averaged 850 per cubic metre, with a range of 300 to 1800. Shorter fibers averaged 1290, with a range of 600 to 3400.
  • In the 20 Group II reference homes, fibers longer than 5 micrometres averaged 280 per cubic metre, with a range from less than 70 to 700. Shorter fibers averaged 580, with a range from less than 70 to 1500.
  • Parallel measurements were made in three homes and at two outdoor points with both the laser monitor and phase contrast microscopy, and the two methods showed rather weak correlation. In the three homes, the monitor gave 540, 400 and 500 fibers per cubic metre, while microscopy gave 3215, 958 and 1816.
  • The author applied a WHO risk formula, assuming lifetime exposure to about 500 fibers per cubic metre in a population of whom 30% smoke. On that basis, the author estimated a lung cancer risk in the order of 10^-6 to 10^-5 and a mesothelioma risk of 10^-5 to 10^-4 for residents of homes with asbestos-cement facades. These are calculated estimates, not observed cases.
• The authors' conclusion: The author concluded that outdoor asbestos-cement building facades are significant sources of airborne fibers inside homes in Upper Silesian towns.
• Limitations the authors state:
  • The author acknowledged that the laboratory and field measurements relied on the MIE Laser Fiber Monitor FM-7400. Phase contrast microscopy was used only for parallel checks in three homes and two outdoor points.
  • Optical instruments like this monitor may be less efficient at detecting curved or more complex fibers.
  • Phase contrast microscopy cannot distinguish asbestos fibers, so the author called for electron microscopy studies to confirm the results in Upper Silesia homes.
  • The dose-risk relationships used for the risk estimates come mainly from workplace exposure.

Topics

Medical terms in this study, explained in our Lexicon: Asbestos-Cement, Respirable Fiber.

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