Pulmonary fibre burden in sheep living in the Biancavilla area (Sicily): preliminary results.

In a national survey on mortality from malignant pleural neoplasms in Italy, aimed at detecting geographic clusters of cases of the disease, the town of Biancavilla, located in a volcanic area of Eastern Sicily, showed high risk of pleural mesothelioma in the absence of occupational asbestos exposure. An environmental survey suggested the stone quarries located in 'Monte Calvario', south-east of the town of Biancavilla, as a possible source of asbestiform fibre exposure. A subsequent crystal-chemistry investigation of the 'Monte Calvario' amphiboles identified the mineral asbestiform fibres as 'fluoro-edenite', a new end-member of the edenite ==> fluoro-edenite series. A collaborative epidemiological and environmental study was initiated to investigate the characteristics of the outbreak of malignant mesothelioma and test the hypothesis of a causal association with exposure to naturally occurring fibres. To investigate if a sheep population could be used to monitor the environmental diffusion of the fibres, we examined lung specimens from 27 culled sheep, at least 3 years old and living near Monte Calvario to check for the presence of fluoro-edenite fibres, using scanning electron microscopy (SEM) analysis and X-ray microanalysis. Fourteen mineral species have been isolated in the mineral particulate matter taken from pulmonary parenchyma, and fluoro-edenite was detected in eight sheep. These preliminary data suggest a possible bio-indicative role of sheep as sentinel animals in the evaluation of environmental fibre diffusion, which merits further investigation. Copryright 2003 Elsevier B.V.