Fluoro-edenitic fibres in the sputum of subjects from Biancavilla (Sicily): a pilot study

Abstract Background An excess of mortality for malignant neoplasms of the pleura in Biancavilla, promoted an investigation for pleural mesothelioma, disclosing 17 cases. As the absence of known sources of asbestos exposure, a local stone quarry, located near the inhabited area, used for the extraction of building materials, was investigated. Amphibolic fibres were found in the quarry and identified as fluoro-edenite "new end-member of the edenite / fluoro-edenite series" and recognized as the fluoro-edenite holotype by International Mineralogical Association – Commission on New Minerals and Mineral Names. A pilot study was performed to verify the feasibility of using spontaneous sputum as an exposure indicator for these fibres, in a context in which the use of aerosol-induced sputum technique would not be easily accepted. Methods Hypothesizing a behaviour of the new fibre analogous to that of asbestos, the determination of the free fibres and the ferruginous bodies in spontaneous sputum was carried out. Phase Contrast Optical Microscope and an Environmental Scanning Electron Microscope fitted with X-ray energy dispersive analysis system (micro-analysis) were used to examine the samples. The criteria for inclusion in the study were: 1) subjects hospitalized for exacerbation of chronic obstructive pulmonary disease symptoms, 2) age ≥ 45 years, 3) residence in Biancavilla for at least 30 years. Results The preliminary findings are related to 12 subjects (7 females and 5 males). Uncoated fibres (with length > 5 μm, diameter No ferruginous bodies were found in any of the samples. The four women with a positive sample were housewives. Of the two men with a positive sample, one was a farmer and the other a mason. Therefore, it may be assumed that the exposure to fluoro-edenitic fibres was mainly environmental. Conclusion The occurrence of the pleural mesothelioma cases and the presence of fluoro-edenitic fibres in spontaneous sputum, evidence the need to study the biological activity of fluoro-edenitic fibres and the implementation of epidemiological monitoring systems.