Occupational exposure to chrysotile in an asbestos cement factory in Kyrgyzstan

Our plain-English summary of Occupational exposure to chrysotile in an asbestos cement factory in Kyrgyzstan, by Z. Kurzhunbaeva, A. Spinazzè, D. Campagnolo, et al (Annals of Work Exposures and Health, 2024).

The study

• Authors: Z. Kurzhunbaeva, A. Spinazzè, D. Campagnolo, S. Rovelli, G. Fanti, O. Kasymov, A. Cattaneo, C. Colosio, D.M. Cavallo
• Journal: Annals of Work Exposures and Health
• Published: 2024;68(9):992-998
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objectives: An increasing number of countries are banning the production and use of asbestos, in compliance with the ratification of the C162 Asbestos Convention and the Basel Convention, and in response to the call for its elimination in the ILO resolution and WHO reports on the health risks associated with asbestos. Nevertheless, several countries, including Kyrgyzstan, are still miners and/or manufacturers of asbestos. The main objective of the study is to assess the occupational exposure to chrysotile of workers engaged in a production facility of asbestos-cement products in Kyrgyzstan.

Methods: Monitored workers (n = 16, for a total of n = 18 samples) were divided into 3 "Similar Exposure Groups" (SEGs; SEG-1: asbestos loading; SEG-2; asbestos-cement mixing; SEG-3: cutting of asbestos-cement sheets) according to EN 689 standard. Samples were collected through personal sampling and subsequently examined by means of scanning electron microscope equipped with an energy-dispersive spectrometer for the compositional analysis of each fibre. The numerical concentration of airborne asbestos fibres was henceforward determined by dividing the number of fibres and the volume of sampled air (expressed in the number of fibres per millilitre of air: ff/ml).

Results: Investigated workers resulted to be exposed to chrysotile fibres. Results (GM ± GSD) outlined extremely high exposure levels for SEG-1 (2.2 ± 2.1 ff/ml) and SEG-3 (4.7 ± 1.6 ff/ml) workers and lower-but still relevant-exposure values for SEG-2 (0.91 ± 2.6 ff/ml) workers.

Conclusions: The results obtained in this case study can help to document potentially critical situations of occupational exposure to asbestos that can still occur nowadays in low and middle-income countries where asbestos is still mined and processed.

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In plain English

This short communication measured airborne chrysotile asbestos among workers at a factory in Kyrgyzstan that made asbestos-cement products using only pure chrysotile. Over three days in July 2023, the authors took 18 eight-hour personal air samples from 16 volunteer workers, six samples in each of three job groups: asbestos loading, asbestos-cement mixing, and cutting of asbestos-cement sheets. Fibres were counted and identified by scanning electron microscopy with chemical analysis. All three groups were exposed to chrysotile fibres. The geometric mean was 2.2 fibres per millilitre (ff/ml) for loading, 0.91 ff/ml for mixing and 4.7 ff/ml for sheet cutting. The authors reported constant non-compliance with the European Union limit, formerly 0.1 ff/ml, being lowered to 0.01 ff/ml and then 0.002 ff/ml. They noted that workers did not always use protective equipment correctly. The authors concluded that the levels resembled those of about 50 years ago in countries that have banned or limited asbestos. They called the study exploratory, with few samples. Most filters were overloaded with dust and corrected afterwards; the authors wrote these results may have a higher uncertainty than standard methods, of unknown size.

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: Exploratory occupational exposure assessment (cross-sectional personal air sampling); published as a short communication
• Who was studied: 16 volunteer workers at one asbestos-cement products company in Kyrgyzstan. 14 were sampled once and 2 twice, for 18 samples. They were split into three Similar Exposure Groups of 6 samples each: asbestos loading (6 workers), asbestos-cement mixing (4 workers) and cutting of asbestos-cement sheets (6 workers). Sampling took place 19–21 July 2023.
• Exposure: Pure chrysotile, used to make asbestos-cement pipes, asbestos-cement sheets (slate), fibre-cement boards and cement-sand tiles. Exposure was measured with eight-hour personal breathing-zone air samples analysed by scanning electron microscopy with energy-dispersive spectrometry.
• Main results:
  • Asbestos loading group (SEG-1, 6 samples): geometric mean 2.2 ff/ml, geometric standard deviation 2.1
  • Asbestos-cement mixing group (SEG-2, 6 samples): geometric mean 0.91 ff/ml, geometric standard deviation 2.6
  • Cutting of asbestos-cement sheets group (SEG-3, 6 samples): geometric mean 4.7 ff/ml, geometric standard deviation 1.6
  • Compared with the European Union occupational exposure limit, the results showed constant non-compliance.
  • The European Union limit of 0.1 ff/ml under Directive 2009/148/EC is being reduced by Directive (EU) 2023/2668 to 0.01 ff/ml (until 20 December 2029) and then to 0.002 ff/ml (from 21 December 2029), both by electron microscopy.
  • Workers did not always follow risk management practices, particularly the use of personal protective equipment, correctly and rigorously.
• The authors' conclusion: The authors concluded that the results depict a situation akin to that of 50 years ago in countries where asbestos has been banned or strongly limited. They wrote that the measured values were in the same order of magnitude as, or higher than, European asbestos-cement measurements from the late 1970s–1980s.
• Limitations the authors state:
  • Most sampled filters were overloaded with dust and fibres and needed an ad-hoc treatment and after-the-fact correction.
  • The corrected results may carry a higher and unknown uncertainty compared with standard methods; the authors could not yet define this uncertainty more precisely.
  • Only 6 samples per group could be obtained, which is the minimum for statistical analysis.
  • Because of the sample size and some deviations from standardized protocols, the study is exploratory rather than confirmatory.
  • Transmission electron microscopy analysis was not performed.

Topics

Medical terms in this study, explained in our Lexicon: Occupational Exposure, Chrysotile, Asbestos-Cement.

Related studies

• An 11-year longitudinal study of the occupational dust exposure and lung function of polyvinyl chloride, cement and asbestos cement factory workers — A. Siracusa, A. Forcina, et al. (1988)
• Simulation tests to assess occupational exposure to airborne asbestos from artificially weathered asphalt-based roofing products — P. Sheehan, F. Mowat, et al. (2010)
• Evaluation of take-home exposure to asbestos from handling asbestos-contaminated worker clothing following the abrasive sawing of cement pipe — A. Abelmann, J.R. Maskrey, et al. (2017)
• Retrospective Exposure Assessment Methods Used in Occupational Human Health Risk Assessment: A Systematic Review — F. Borghi, L.A. Mazzucchelli, et al. (2020)
• Assessment of airborne asbestos exposure at an asbestos cement sheet and pipe factory in Iran — H. Marioryad, H. Kakooei, et al. (2011)
• Simulation tests to assess occupational exposure to airborne asbestos from asphalt-based roofing products — F. Mowat, R. Weidling, et al. (2007)

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