This study reviews a series of 811 malignant pleural mesothelioma cases, diagnosed at hospitals in Trieste and Monfalcone districts of north eastern Italy, a narrow coastal strip with a population of about three lakh, in the period 1968-2008. The diagnosis was based on histological examination in 801 cases, and cytological findings in 10. Necropsy was performed in 610 cases. Occupational histories were obtained directly from the patients or their relatives through personal or telephone interviews. Routine lung sections were examined for asbestos bodies in 500 cases. In 143 cases asbestos bodies were isolated and counted by chemical digestion of the lung tissue using the Smith-Naylor method. The series included 717 men and 94 women aged between 32 and 93 years (mean 69.2 years). Detailed occupational data was obtained for 732 cases.
The majority of patients had marine jobs - shipbuilding (449 cases), maritime trades (56 cases), and port activities (39 cases). The nature of work of other patients included a variety of occupations, with non-shipbuilding industries being the most common. Thirty-four women cleaned the work clothes of family members occupationally exposed and hence had a history of asbestos exposure at home. Most of the patients had their first exposure to asbestos before 1960. The latency period ranged between 13 and 73 years (mean 48.2). Latency period among insulators and dock workers were shorter than other categories. Asbestos bodies were detected on routine lung sections in 343 cases (68.6%). Lung asbestos body burdens after isolation ranged between two to 10 millions bodies per gram of dried tissue. Despite some limitations in the use of asbestos in this area since the 1970s, the incidence of tumor remained high during the last years.
