Asbestos exposure diagnosis in pulmonary tissues

Abstract

The diagnosis of asbestosis requires different criteria depending on whether it is in a clinical or medical/legal setting. In the latter context, only when a "diffuse interstitial fibrosis associated to asbestos bodies (ABs)" is present, it can be said to be asbestosis. Considering the medical/legal setting, the diagnosis must be certain and proven. Unfortunately, it is often difficult to identify ABs by light microscopy (LM), but this does not mean that the diagnosis should be clinically excluded. Other parameters are important, such as working history and/or diagnostic imaging. In addition to LM, normally used for diagnosis, there are other techniques, e.g.: scanning electron microscopy with attached microanalysis microprobe (SEM/EDS), but they require tissue digestion and higher cost. A new approach with micro-Raman spectroscopy and SEM/EDS techniques is able to analyse histological sections without other manipulations that could interfere with analysis of asbestos fibres. In this work, we propose an algorithm for asbestosis diagnosis, especially in the forensic medical field, demonstrating the importance of close collaboration between multiple professionals.

Keywords: asbestos; diagnosis; lung; mineralogist; pathologist.

Figure 1.

Working scheme for asbestos evaluation from the clinicians to the pathologists and mineralogist evaluations for asbestos in tissues. In this scheme, “NO” does not exclude working exposure, but only that it is not possible to obtain a confirmation of the presence of asbestos. (A) Asbestos body in a H&E stained section from lung tissue (highlighted by the circle, magnification 40X). (B) Asbestos body observed using the LM microscope annexed to the Raman spectroscope (magnification 100X) in a non-stained histological section from lung. (C) Asbestos body deposited on filters after tissue removal observed by LM at magnification 40X. (D) SEM image of an asbestos body observed using backscattered (DualBSD) detector. Backscattered electrons highlight the morphology and the atomic number of the elements composing the different areas of the samples (a lighter grey corresponds to a higher atomic number of the element). (E) An example of EDS spectrum obtained on a free fibre of chrysotile.