US EPA

7477922 

Journal Article 

Persistence of long asbestos and talc fibres in human lung tissue 

Rodelsperger, K; Bruckel, B; Arhelger, R; Knopp, J 

1995 

1 

Zentralblatt für Arbeitsmedizin, Arbeitsschutz und Ergonomie
ISSN: 0944-2502
EISSN: 2198-0713 

45 

10 

410-421 

German 

Information on the bio-persistence of different types of fibres in human lung tissue can only be obtained from a lung dust fibre analysis in combination with measurements and case history data on the inhalative intake of fibre dust at the workplace. Although the use of asbestos consisted of 94% by weight of chrysotile and only 6% by weight of amphibole, it is still predominantly amphibole fibres which are found in the lung tissue following inhalative intake of asbestos fibre dust at the workplace, even amongst fibres with a length L ≥ 5 μm. In confirmation of the results of animal experiments, an increase of the fibre concentration in the lung tissue with the class of severity corresponding to inhalative intake or with the estimated quantitative value of the cumulative dose off the dust, is observed only in the case of amphibole fibres, and not with chrysotile fibres. The inhalative intake of fibre dust in the environment in general consists predominantly of non-asbestos fibres. However, in the case of 34 patients with no indication of exposure to asbestos at their workplace, at least as many asbestos fibres were found - these being mainly chrysotile - as non-asbestos fibres. It can be concluded that the biopersistence of non-asbestos fibres is generally lower, even in comparison to chrysotile. The significantly higher proportion of long talc fibres however indicates the particular biopersistence of this type of fibre. Although talc is considered as a platelet mineral, talc fibres occured much more frequently than asbestos fibres in 12 commercial talc powders. The highest concentrations of talc fibres, of up to 1.140.000 F/mg, are found in cosmetic/pharmaceutical powders. Approximately 5 times lower talc fibre concentrations, but the highest asbestos fibre concentrations, of up to 30.000 chrysotile or actinolite/tremolite F/mg, are found in technical products. In fact the lung dust fibre analysis of patients with definite case history evidence of a substantial use of talc regularly register significantly higher talc fibre concentrations of up to 5.3 million fibres of length L ≥ 5 μm per gram of dry lung tissue, and this even decades after the exposure. Only after the use of technical products are actinolite/tremolite fibres, observed in addition to talc fibres, and then in a proportion corresponding roughly to that found in the product itself. It can be concluded that talc fibres therefore have a higher biopersistence than chrysotile fibres. The borderline findings, observed in a case control study of mesothelioma patients with talc fibres, of an increased odds ratio, are supported by these results. 

asbestos; bio-persistence; carcinogenicity; lung dust fibre analysis; article; asbestosis; drug toxicity; dust exposure; occupational lung disease