Malignant mesotheliomas in textile rag sorters

Objectives: To analyse the asbestos exposure characteristics and mesothelioma trend in textile workers operating in the larger Tuscan textile industrial province of Prato between 1988 and 2012.

Methods: All cases of textile workers recorded by the Tuscan mesothelioma register are considered. The demographic and clinical characteristics and asbestos exposure of cases working in the province of Prato are examined. Crude incidence rates between 1988 and 2012 and their 95% confidence intervals (CI) are calculated in rag sorters and other textile workers. The trends of standardized rates are also evaluated, as well as the sources of occupational asbestos exposure from occupational histories of cases affected by other asbestos-related diseases in rag sorters.

Results: One hundred and seventy-two malignant mesotheliomas (MMs) have been diagnosed in textile workers in Tuscany. Among these, 46.5% were residents in the province of Prato at the time of diagnosis, half of whom working as rag sorters. All rag sorters with MM are classified as occupationally asbestos exposed, while 71.7% are other textile workers exposed to asbestos. The estimated crude incidence rate in rag sorters in Prato ranges from 74.1×100000 (95% CI: 52.5-101.8) to 166.8×100000 (95% CI: 118.1-229.0). The standardized rates in Prato rag sorters appeared higher throughout the 1990s while in other Prato textile workers the rates increased later on, at the very end of the 1990s. Another 40 cases of asbestos-related diseases in rag sorters were also collected.

Conclusions: A very high incidence of MMs was observed in textile workers in Prato, especially among rag sorters. This result, together with the high number of other asbestos-related diseases in rag sorters, strongly supports the hypothesis of diffuse asbestos exposure in rag sorting, in the absence of any other relevant aetiological factor for malignant mesothelioma.