In a recent epidemiological study, researchers investigated mortality from malignant
pleural neoplasms in Italy, and they detected some geographic clusters of cases of this disease. We found a town located in a volcanic area of eastern Sicily to be of special interest. The residents, some of whom were diagnosed with pleural
mesothelioma, had never had any relevant exposure to
asbestos during their professional lives. The results of an environmental survey suggested that a possible cause of
asbestos exposure was the stone quarries near the town. The products of the quarries contain fibrous
amphiboles, which are used widely in the local building industry. These fibrous
amphiboles were identified as intermediate phases between
tremolite and
actinolite. Samples were collected from buildings in the town, and concentrations of
amphibole fibers were evaluated. Fibrous phases were detected in 71% of the samples, and fiber concentrations ranged from a few thousand to more than 4 x 10(4) fibers/mg of material. In addition, we conducted a study on the
mineral fiber lung burden in a pleural
mesothelioma case. Many
mineral fibers that were classified as the same
tremolite-
actinolite fibrous
amphibole found in the quarries and in the building materials were detected in the lung tissue. The results suggest that the inhabitants of the town we studied had been exposed for several decades to
asbestos fibers that were present in the material extracted from the local stone quarries. The material was subsequently used in the building industry, and this has caused an increased risk of pleural
mesothelioma in the area.