Impact of an asbestos cement factory on mesothelioma incidence in a community in Italy

Background: Broni is a small town (9000 inhabitants) in the province of Pavia, Lombardy, north-west Italy, where the second largest Italian asbestos cement factory (Fibronit) was in operation between 1932 and 1993. Based on Lombardy Mesothelioma Registry (RML) data (2000–2011), we previously showed a high impact of asbestos exposure on malignant mesothelioma (MM) incidence among Fibronit workers, their families, and people living in Broni and in the nearby town of Stradella (11,000 residents). Given the great concern of the community, we have recently updated the data regarding 5 more years (2012–2016). Methods: From the RML database we extracted subjects who ever worked in Fibronit, their family members, ever residents in Broni, and subjects living in Stradella and nearby towns at the time of diagnosis. For each type of exposure we calculated standardized incidence ratios (SIR = observed/expected cases). Results: In the period 2000–2016 we registered 56 cases (2.52 expected, SIR = 22.2), 49 men (41 pleural, 8 peritoneal MM), 7 women (5 pleural, 2 peritoneal MM) with past occupational exposure in Fibronit. Among subjects never occupationally exposed and never exposed to extra-occupational sources unrelated to Fibronit, we counted 39 cases (4.24 expected, SIR = 9.2), 10 men (all pleural MM), 29 women (28 pleural, 1 peritoneal MM) in Fibronit workers’ families, 91 pleural mesothelioma cases (7.43 expected, SIR = 12.2, 31 men, 60 women), ever residents in Broni, and 25 pleural mesothelioma cases (3.05 expected, SIR = 8.2, 6 men, 19 women) living in Stradella at the time of diagnosis. The overall number of excess cases was about 194 (211 against 17.24 expected). In the remaining adjacent (No. 8) and surrounding (No. 17) municipalities (32,000 people) there were 7 cases (1 men, 6 women, 8.85 expected). Conclusion: The mesothelioma burden related to the asbestos cement factory is still high on factory workers, their families, and residents in Broni and Stradella towns.