Unusually high incidence of malignant pleural mesothelioma in a town of eastern Sicily: An epidemiological and environmental study

In a recent epidemiological study, researchers investigated mortality from malignant pleural neoplasms in Italy, and they detected some geographic clu sters 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 we re diagnosed with pleural mesothelioma, had never had any relevant exposure to asbestos during their professional lives. The results of an environment al survey suggested that a possible cause of asbestos exposure was the ston e quarries near the town. The products of the quarries contain fibrous amph iboles, which are used widely in the local building industry. These fibrous amphiboles were identified as intermediate phases between tremolite and ac tinolite. Samples were collected from buildings in the town, and concentrat ions of amphibole fibers were evaluated. Fibrous phases were detected in 71 % of the samples, and fiber concentrations ranged from a few thousand to mo re 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 miner al fibers that were classified as the same tremolite-actinolite fibrous amp hibole 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 s tudied had been exposed for several decades to asbestos fibers that were pr esent in the material extracted from the local stone quarries. The material was subsequently used in the building industry, and this has caused an inc reased risk of pleural mesothelioma in the area.