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 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.

[Asbestos fiber count in extra-pulmonary tissues]. / Riscontro di fibre di asbesto in tessuti extrapolmonari.

Most autoptic tissues of three men (two with pulmonary asbestosis and one without any exposure to asbestos) were analyzed by transmission electron microscopy and energy dispersion spectrometry for the quantitative and qualitative evaluation of asbestos fibers. Preliminary results indicate that only in cases with occupational exposure were found asbestos fibers (in lung, pleura , bladder, kidney and liver). These results allow interesting speculations on some environmental pathogenetic questions and deserve further investigations.

[Concentration of asbestos fibers in urothelial tumors and in the neoplasm-free bladder wall]. / Concentrazione di fibre di asbesto nei tumori uroteliali e nella parete vescicale esente da neoplasia.

The aim of our study was to search the eventual presence of asbestos fibers in the neoplastic tissue of 13 cases of bladder carcinoma and in the normal vesical tissue of 12 control cases without neoplasia and operated upon for other urologic pathologies. To all patients a standardised questionnaire has been administered in order to ascertain the entity of the eventual exposition to asbestos. The organic component of the tissues has been oxidated at low temperature in atomic oxygen plasma and the residual inorganic component has been analysed by transmission electronic microscopy and energy dispersion spectrometry. We have found asbestos fibers only in two over the 25 examined samples; in both cases they belonged to patients affected by the neoplasia and in one of them also by pulmonary asbestos. The procedures that we used in this study, in respect to our other experiences, allowed us to reduce the risk of contamination of the tissues by asbestos, as it is shown by the lower number of cases with positive finding of fibers and by lower concentration of fibers in the positive cases.

Characterization of asbestos fibers in pleural tissue from 21 cases of mesothelioma.

Pleural biopsies from 21 patients with pleural mesothelioma and different asbestos exposure were analyzed by means of analytical electron microscopy with the aim of investigating the presence, quantity, types and sizes of asbestos fibers in pleural tissue. The majority of fibers found consisted of ultrathin (< 0.3 micron) and short (< 5 microns) fibers regardless of asbestos types and subject exposure. Concentrations appeared to be poorly related to the estimated exposure level. Fiber dimensions appeared to be the most important characteristic which determined their translocation in the pleural region.

Mineral fibres and dusts in lungs of subjects living in an urban environment.

We have undertaken a study on 200 autopsy lung samples collected from subjects who lived in the Rome urban area and were not occupationally exposed to mineral dusts. The samples belonged to subjects who died aged between 15 and 65, both male and female. Subjects suffering from diseases and drug addicts were excluded. The purpose of this investigation was to determine whether any correlation existed between subjects' life-style, in particular smoking habits, and the presence of mineral fibres and dusts in their lungs. The data obtained were compared with those on airborne mineral dusts in the environment of the subjects themselves, particularly data on the concentration and types of mineral fibres present in that environment.

Mineral particles in the lungs of subjects resident in the Rome area and not occupationally exposed to mineral dust.

We studied the inorganic particulate contained in the lung parenchyma of 10 subjects (5 males and 5 females) resident in an urban area and not occupationally exposed to dusts. A total of 17 mineral types were identified, along with 16 metal elements in the form of oxides and sulfides. Approximately 70% of the minerals were made up of phyllosilicates, in particular clay, mica, and talc; three metal elements, Fe, Al, and Ti, accounted for more than 75% of the recovered oxide particles. The mean concentration of the observed inorganic particles was approximately 1.8 X 10(5) pp/mg dry tissue. No significant differences were observed in terms of total particulate concentration in the various areas of the lungs and between the right and left lung. Instead we observed a larger concentration of fibrous particles in the upper lobes. The analysis of the data made it possible to determine the presence of a high degree of correlation between the concentrations of silicates and the concentrations of metal oxides and sulfides, implying the existence of a ubiquitous environmental source of these mineral particles. The frequent observation of tremolite fibers is remarkable. This finding, confirmed elsewhere, indicates that the magnitude of the sources of these fibers in the environment, constituted by contaminated talc dusts, has been underestimated until today.