Epidemiological surveillance of mesothelioma mortality in Italy

Our plain-English summary of Epidemiological surveillance of mesothelioma mortality in Italy, by L. Fazzo, G. Minelli, M. De Santis, et al (Cancer Epidemiology, 2018).

The study

• Authors: L. Fazzo, G. Minelli, M. De Santis, C. Bruno, A. Zona, S. Conti, P. Comba
• Journal: Cancer Epidemiology
• Published: 2018;55:184-191
• Cited by: 12 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Malignant mesothelioma (MM) is causally linked to asbestos exposure with an estimated etiological fraction of 80% or more.

Methods: Standardized rates of all mesothelioma (C45, ICD-10) and malignant pleural mesothelioma (C45.0, ICD-10) mortality in Italy were computed at national and regional levels, for the period 2003-2014. Standardized Mortality Ratios (SMRs, with 95% Confidence Intervals) were calculated for each of the 8047 Italian municipalities, for both diseases, with respect to Regional figures. A geographical clustering analysis at municipal level was performed, applying SatScan methods.

Results: In Italy, 16,086 persons (about 1,340/year) died for MM, in analysed period. National Standardized rates of MM mortality are 3.65/100,000 in men and 1.09/100,000 in women, with an increasing annual trend, among male population. The highest rates were found in men from Northern Regions. Significant clusters (p < 0.10) were found corresponding to areas that hosted major asbestos-cement plants, naval shipyards, petrochemical plants and refineries. Furthermore, excesses were found corresponding to chemical and textile industries; the latter involving, particularly, female population. Excesses were found also in areas near the chrysotile mine of Balangero, and in Biancavilla, a town with a stone quarry contaminated by fluoro-edenitic fibres; an excess of MM mortality was observed among male population living in a minor island where a Navy shipyard is located.

Conclusions: Mortality for mesothelioma in Italy is still increasing, twenty-six years after the asbestos ban. Epidemiological surveillance of mesothelioma mortality allows to detect the temporal trend of the disease and highlights previously unknown or underestimated sources of asbestos exposure.

Copyright © 2018 Elsevier Ltd. All rights reserved.

In plain English

Using Italian death records for 2003 to 2014, the authors calculated standardized mesothelioma death rates nationally and regionally, compared observed with expected deaths (standardized mortality ratios) in each of 8047 municipalities, and searched for geographic clusters. Individual asbestos exposure was not measured. 16,086 people died of malignant mesothelioma (11,487 men, 3.65 per 100,000; 4599 women, 1.09 per 100,000), 13,051 from pleural mesothelioma. Rates rose significantly, especially in men; northern regions exceeded national rates. Male clusters lay near asbestos-cement plants, petrochemical plants, refineries, shipyards and harbours. Female clusters appeared near shipyards and asbestos-cement plants. Excesses were reported in Biancavilla, a town near a stone quarry with fluoro-edenitic fibres, and among men in Balangero, site of a chrysotile mine (3 cases). For the first time since surveillance began, a significant male cluster appeared on La Maddalena, an island with a Navy shipyard. The male-to-female ratio of pleural mesothelioma deaths did not differ by population density. The authors concluded that asbestos's health impact continues after Italy's ban. They cautioned that causes of death may be misclassified and that rarity limits statistical power.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: National geographical mortality surveillance study: standardized death rates by region, standardized mortality ratios (SMRs) by municipality, and spatial cluster analysis of death-certificate data
• Who was studied: All deaths from malignant mesothelioma recorded in Italy from 2003 to 2014: 16,086 people (11,487 men and 4599 women), analysed across 21 regions and autonomous provinces and 8047 municipalities
• Exposure: Individual exposure was not measured. Excess mortality and clusters were interpreted against local industries and sites known as certain or possible asbestos sources: asbestos-cement plants, petrochemical industries and refineries, shipyards and harbour areas, textile industries, the Balangero chrysotile mine, and the Biancavilla quarry with fluoro-edenitic fibres.
• Main results:
  • Malignant mesothelioma deaths, 2003 to 2014: 11,487 men (3.65 per 100,000) and 4599 women (1.09 per 100,000)
  • Malignant pleural mesothelioma deaths: 9397 men and 3654 women, with rates of 2.98 and 0.86 per 100,000 respectively
  • Standardized rates of all mesothelioma and of pleural mesothelioma mortality rose significantly from 2003 to 2014 (p of 0.001 or less) in the overall population and particularly in men
  • Northern regions (Liguria, Piemonte, Friuli Venezia Giulia, Lombardia and Valle d'Aosta) had mesothelioma and pleural mesothelioma mortality rates above the national ones
  • In the overall population, 247 municipalities had a significant excess of mesothelioma mortality and 217 a significant excess of pleural mesothelioma mortality (based on 3 or more observed cases)
  • Significant male clusters were in areas with large industrial settlements: asbestos-cement plants, petrochemical industries and refineries, shipyards and harbour areas
  • Significant female clusters for all and pleural mesothelioma were found in correspondence to shipyards (Monfalcone, Livorno, Napoli), among other sites
  • Men in Balangero, site of a chrysotile mine, had an excess based on 3 cases: SMR 309 (95% CI 105 to 910)
  • Excesses of all and pleural mesothelioma mortality were observed in both women and men living in Biancavilla, where a stone quarry contains fluoro-edenitic fibres
  • For the first time since the surveillance began, a significant mesothelioma cluster was found in the male population of La Maddalena, an island with an Italian Navy shipyard
  • Significant clusters were found in areas not previously highlighted: around a turbine factory (Legnano), chemical plants (Mira, Cengio and Rosignano Marittima) and steel industries (Terni and Dalmine)
  • The male-to-female ratio of pleural mesothelioma deaths in Italy was 2.58, with no differences between municipalities of high, medium and low population density. The authors said this did not support an excess urban risk in women.
• The authors' conclusion: The authors concluded that the health impact of asbestos continues in Italy after the national ban, for both occupational and environmental exposures. They suggested the rise could be due to the disease's long latency and to residual asbestos sources still releasing fibres.
• Limitations the authors state:
  • Possible misclassification of causes of death, and low statistical power because mesothelioma is rare
  • About 12% of deaths were mesothelioma of unspecified site; if most were pleural, pleural mesothelioma mortality may be underestimated
  • Municipal SMR results could be affected by random variation
  • The cluster analysis is less specific than the SMR analysis

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Mesothelioma, Malignant Mesothelioma, Asbestos Exposure, Pleural Mesothelioma, standardized mortality ratio (SMR), confidence interval, Asbestos-Cement, Chrysotile.

Related studies

• The Epidemiological Surveillance of Mesothelioma Mortality in Italy as a Tool for the Prevention of Asbestos Exposure — L. Fazzo, G. Minelli, et al. (2023)
• Pleural mesothelioma mortality and asbestos exposure mapping in Italy — L. Fazzo, M. De Santis, et al. (2012)
• Peritoneal mesothelioma mortality in Italy: Spatial analysis and search for asbestos exposure sources — A. Zona, L. Fazzo, et al. (2019)
• Mesothelioma incidence surveillance systems and claims for workers' compensation. Epidemiological evidence and prospects for an integrated framework — A. Marinaccio, A. Scarselli, et al. (2012)
• Burden of Mortality from Asbestos-Related Diseases in Italy — L. Fazzo, A. Binazzi, et al. (2021)
• 24 years of pneumoconiosis mortality surveillance in Australia — D.R. Smith, P.A. Leggat (2006)

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