The relationship between malignant mesothelioma and an asbestos cement plant environmental risk: a spatial case-control study in the city of Bari (Italy)

Our plain-English summary of The relationship between malignant mesothelioma and an asbestos cement plant environmental risk: a spatial case-control study in the city of Bari (Italy), by M. Musti, A. Pollice, D. Cavone, et al (International Archives of Occupational and Environmental Health, 2009).

The study

• Authors: M. Musti, A. Pollice, D. Cavone, S. Dragonieri, M. Bilancia
• Journal: International Archives of Occupational and Environmental Health
• Published: 2009;82(4):489-97
• Cited by: 43 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objectives: To estimate the mesothelioma risk and environmental asbestos exposure (EAE) due to an asbestos-cement plant.

Methods: A spatial case-control study including 48 malignant mesothelioma (MM) cases occurred in the period 1993-2003 selected from the regional mesothelioma register (RMR) and 273 controls. The disease risk was estimated by means of a logistic-regression model, in which the probability of disease-occurrence is expressed as a function of the classes of distances. A non-parametric method was applied to estimate the full relative risk surface.

Results: Significant MM odds ratio of 5.29 (95 CI: 1.18-23.74) was found for people living within a range up to 500 m centered on the plant. The non-parametric estimation of relative risk surface unveiled a marked peak near the plant not paralleled by the spatial distribution of controls.

Conclusion: Evidence of an association between mesothelioma risk and EAE is highlighted. The role played by the RMR in increasing the public health local authorities awareness is stressed.

In plain English

This spatial case-control study asked whether malignant mesothelioma in Bari, Italy, was linked to living near the Fibronit asbestos-cement plant (active 1934 to 1989). In 1974 the company reported using about 80% chrysotile, 15% crocidolite and 5% amosite. The authors compared 48 deceased cases from 1993 to 2003, drawn from 108 in the regional register and without occupational, domestic or household asbestos exposure, with 273 controls randomly chosen from Bari deaths from other causes. Exposure was the distance from the plant to each person's longest-held address, excluding addresses from the 15 years before diagnosis or death. Living within 500 m, versus beyond 2,000 m, had a sex- and age-adjusted odds ratio of 5.29 (95% CI 1.18 to 23.74; 4 cases, 6 controls). Other bands had odds ratios above one, of questionable statistical significance. A distance-risk model gave P = 3.2 × 10⁻⁵. The authors concluded there was evidence of an association between mesothelioma and asbestos pollution around the plant. They noted that controls could not be checked for occupational exposure, that matching on sex and age failed, and that cases were few.

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: spatial case-control study using a regional mesothelioma register
• Who was studied: 48 deceased malignant mesothelioma cases resident in Bari, Italy, diagnosed 1993 to 2003, with no occupational, domestic or household asbestos exposure (out of 108 MM cases in the Apulia regional register), and 273 controls randomly selected from Bari municipal death records among deaths from causes other than mesothelioma
• Exposure: Environmental (neighborhood) exposure from the Fibronit asbestos-cement plant in Bari. The plant was active 1934 to 1989, and in 1974 the company notified use of a blend of about 80% chrysotile and 20% amphiboles (15% crocidolite and 5% amosite). Exposure was measured by the distance of each person's prevalent (longest-held) residence from the plant. Addresses from the last 15 years before diagnosis (cases) or death (controls) were excluded.
• Main results:
  • People whose prevalent residence was 0 to 500 m from the plant (4 cases, 6 controls) had an odds ratio of 5.29 (95% CI 1.18 to 23.74) compared with those beyond 2,000 m, adjusted for sex and age.
  • Other distance bands had odds ratios above one, but the authors described their statistical significance as questionable: 500 to 1,000 m, OR 1.49 (95% CI 0.58 to 3.82); 1,000 to 1,500 m, OR 1.27 (95% CI 0.49 to 3.71).
  • The 1,500 to 2,000 m band had an OR of 2.31 (95% CI 0.88 to 6.06). The authors explained this by a secondary cluster near the Torre Quetta beach, and said it could not be associated with pollution around the plant.
  • A likelihood ratio test of a model in which mesothelioma odds depend on distance from the plant gave P = 3.2 × 10⁻⁵. The authors described this as strong evidence in favor of the distance model.
  • Cases' addresses tended to be nearer the plant than controls' addresses, but a Kolmogorov–Smirnov test was not statistically significant (P = 0.32).
  • The Cuzick and Edwards clustering test was not conclusive (p = 0.07 and p = 0.08).
  • The risk map showed a peak near the plant. It also showed a secondary cluster of six cases east of the plant, near the Torre Quetta urban beach, where unlicensed waste disposal from the plant occurred in 1950 to 1970.
• The authors' conclusion: The authors concluded that their combined results provided a little but decisive evidence of an association between malignant mesothelioma incidence and asbestos environmental pollution around the asbestos-cement plant.
• Limitations the authors state:
  • Matching cases and controls for sex and date of birth failed because records before 1998 were not computerized. Only matching by calendar date of death was considered reliable, so sex and age were handled as covariates in the models.
  • The way controls were selected did not let the authors verify that controls lacked occupational asbestos exposure, or obtain any exposure information other than distance to the plant.
  • The number of cases was small.
  • No environmental asbestos concentration data were available for the main production period (1940s and 1960s), so distance from the plant was used as a proxy for exposure.

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: Malignant Mesothelioma, Asbestos-Cement, Case-Control Study, Mesothelioma, Asbestos Exposure, Relative Risk, Odds Ratio.

Related studies

• Monitoring of airborne asbestos fibers in an urban ambient air of Shahryar City, Iran: levels, spatial distribution, seasonal variations, and health risk assessment — F. Taghizadeh, A.J. Jafari, et al. (2019)
• Increased risk of lung cancer mortality among residents near an asbestos product manufacturing plant — S. Kumagai, N. Kurumatani, et al. (2010)
• Environmental asbestos exposure and mesothelioma cases in Bari, Apulia region, southern Italy: a national interest site for land reclamation — L. Vimercati, D. Cavone, et al. (2018)
• Environmental asbestos exposure and clustering of malignant mesothelioma in community: a spatial analysis in a population-based case-control study — C. Airoldi, C. Magnani, et al. (2021)
• Epidemiological patterns of asbestos exposure and spatial clusters of incident cases of malignant mesothelioma from the Italian national registry — M. Corfiati, A. Scarselli, et al. (2015)
• Estimate of environmental and occupational components in the spatial distribution of malignant mesothelioma incidence in Lombardy (Italy) — D. Catelan, D. Consonni, et al. (2020)

Browse more research in International Archives of Occupational and Environmental Health, or return to medical research.