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Asbestos Hazards

Diagnostic limitations of lung fiber counts in asbestos-related diseases

Diagnostic limitations of lung fiber counts in asbestos-related

Joachim Schneider
1 , Rolf Arhelger 1 , Bernd Brückel 2 , Xaver Baur 3
Institut und Poliklinik für Arbeits- und Sozialmedizin,, 2 Institut und Poliklinik für Arbeits- und Sozialmedizin, 3 European Society for Environmental
and Occupational Medicine,

Keywords: Lung dust analysis, asbestos diseases, ferruginous (asbestos) bodies, chrysotile, crocidolite


Lung dust fibre analyses have been used by some pathologists to estimate past asbestos

exposure in the workplace and its related health risks. Asbestos, however, especially the

predominately applied chrysotile asbestos type, undergoes translocation, clearance and

degradation in the lungs.


We quantified the asbestos fibre and ferruginous (asbestos) body (FB) content in human

tissue with respect to the German asbestos ban in 1993 and the interim period of more

than 20 years in order to evaluate the diagnostic evidence of these analyses for

asbestos-related diseases (ARD).


Lung dust analyses have been used in empirical assessments of ARD since 1982. Tissue

samples of about 2 cm
3 were used and processed in standardized manner. FB was
analysed by light microscopy and asbestos fibres by scanning transmission electron

microscopy (STEM).


Chrysotile and amphibole fibre concentrations in the lung tissue depend roughly on the

cumulative asbestos exposure levels in the workplace.

However, the concentration of lung asbestos fibre and FB depends on the year of

examination and especially on the interim period. As the interim period increases, the

asbestos fibre burden decreases. There is no relationship between FB and chrysotile

asbestos fibre concentrations and only a weak correlation between FB and crocidolite

fibre concentrations.

There was no significant difference in chrysotile and amphibole fibre concentrations as

well as in FB counts between the different ARD.


Due to the length of interim periods, a past exposure to chrysotile or amphibole asbestos

can no longer be detected with FB or asbestos fibre measurement in lung tissue. This

means that negative results of such measurements cannot disprove a qualified

occupational case history of asbestos exposures and the related health risks due to the

fibrogenic and carcinogenic potential of asbestos.

Short residence time of chrysotile asbestos in lung tissue and implications for diagnosis and compensation

The silicate mineral asbestos is categorized into two main groups based on fiber structure: serpentine asbestos (chrysotile) and amphibole asbestos (crocidolite, amosite, anthophyllite, tremolite, and actinolite). All forms of asbestos are capable of inducing mesothelioma, lung cancer, asbestosis, and other diseases.
However, unlike other forms of asbestos, chrysotile asbestos, the predominant form of asbestos in world markets today and in the past is well documented to have only a short residence time in lung tissue.
The World Health Organization (WHO) runs a campaign to stop the use of all forms of asbestos, including chrysotile asbestos. Also the International Agency for Research on Cancer (IARC) has classified chrysotile as a group 1 carcinogen.
The following article deals with chrysotile asbestos and a recent publication that suggests fibre detection in lung tissue for the diagnosis of asbestos disease, which would be problematic for the compensation of affected workers in practice:



Ongoing downplaying of the carcinogenicity of chrysotile asbestos by vested interests

By Xaver Baur and Arthur L. Frank

The persisting strong influence of vested asbestos-related interests in workers and public health issues including regulations and compensation necessitate ongoing alertness, corrections and appropriate reactions in scientific as well as public media and policy advisory bodies.

Industries that mine, manufacture and sell asbestos or asbestos-containing products have a long tradition of promoting the use of asbestos, while placing the burden of economic and health costs on workers and society. This has been successfully done in recent years and decades in spite of the overwhelming evidence that all asbestos types are carcinogenic and cause asbestosis. They continue to be extremely active by using slogans such as chrysotile can be used safely.

Another approach of the asbestos industry and of some of its insurance agencies is to broadly defeat liability claims of asbestos victims.

In doing so they systematically use inappropriate science produced by their own and/or by industry-affiliated researchers. Some of the latter were also engaged in producing defense material for other industries including the tobacco industry. Frequent examples of distributing such disinformation include questioning or denying established scientific knowledge about adverse health effects of asbestos. False evidence continues to be published in scientific journals and books
Chrysotil carcinogenicity