Pleural mesothelioma and occupational and non-occupational asbestos exposure: a case-control study with quantitative risk assessment.
OBJECTIVE
Casale Monferrato (north west Italy) is an area with an exceptionally high incidence of mesothelioma caused by asbestos contamination at work and in the general environment from the asbestos-cement Eternit plant that was operational until 1986. The purpose of this study was to quantify the association between pleural malignant mesothelioma (PMM) and asbestos cumulative exposure using individual assessment of environmental and domestic exposure, as well as of occupational exposure.


METHODS
This population-based case-control study included cases of PMM diagnosed between January 2001 and June 2006 among residents in the Casale Monferrato Local Health Authority. Population controls were randomly sampled, matched by age and sex to cases. Cumulative exposure was estimated to account for the lifelong exposure history. Analyses were conducted using unconditional logistic regression models adjusting for gender, age at diagnosis and type of interview (direct or proxy respondents).


RESULTS
200 PMM cases of 223 eligible cases (89.7%) and 348 (63%) of 552 eligible controls accepted to be interviewed. ORs increased with cumulative exposure index (p<0.0001) from 4.4 (CI 95% 1.7 to 11.3) (<1 f/mL-years) to 62.1 (CI 95% 22.2 to 173.2) (≥10 f/mL-years). Among subjects never occupationally exposed, corresponding ORs were 3.8 (CI 95% 1.3 to 11.1) and 23.3 (CI 95% 2.9 to 186.9) (reference: background level of asbestos exposure). ORs of about 2, statistically significant, were observed for domestic exposure and for living in houses near buildings with large asbestos cement parts.


CONCLUSIONS
Risk of PMM increased with cumulative asbestos exposure and also in analyses limited to subjects non-occupationally exposed. Our results also provide indication of risk associated with common sources of environmental exposure and are highly relevant for the evaluation of residual risk after the cessation of asbestos industrial use.
Department of Translational Medicine, Unit of Medical Statistics and Cancer Epidemiology, CPO Piemonte and University of Piemonte Orientale, Novara, Italy.
Daniela
D
Ferrante
Unit of Cancer Epidemiology, CPO Piemonte and University of Turin, Turin, Italy Interdepartmental Centre G. Scansetti for Studies on Asbestos and other Toxic Particulates, University of Turin, Turin, Italy.
Dario
D
Mirabelli
Department of Translational Medicine, Unit of Medical Statistics and Cancer Epidemiology, CPO Piemonte and University of Piemonte Orientale, Novara, Italy.
Sara
S
Tunesi
Unit of Cancer Epidemiology, CPO Piemonte and University of Turin, Turin, Italy Interdepartmental Centre G. Scansetti for Studies on Asbestos and other Toxic Particulates, University of Turin, Turin, Italy.
Benedetto
B
Terracini
Department of Translational Medicine, Unit of Medical Statistics and Cancer Epidemiology, CPO Piemonte and University of Piemonte Orientale, Novara, Italy Interdepartmental Centre G. Scansetti for Studies on Asbestos and other Toxic Particulates, University of Turin, Turin, Italy.
Corrado
C
Magnani
D000368:Aged; D001194:Asbestos / Q000009:adverse effects*; D002273:Carcinogens; D016022:Case-Control Studies; D060389:Construction Industry; D003252:Construction Materials / Q000009:adverse effects; D004781:Environmental Exposure / Q000009:adverse effects*; D004787:Environmental Pollution / Q000009:adverse effects*; D005260:Female; D006798:Housing; D006801:Humans; D015994:Incidence; D007558:Italy; D016015:Logistic Models; D008168:Lung / Q000473:pathology; D008175:Lung Neoplasms / Q000209:etiology*; D008297:Male; D008654:Mesothelioma / Q000209:etiology*; D000086002:Mesothelioma, Malignant; D008875:Middle Aged; D009784:Occupational Diseases / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects; D016017:Odds Ratio; D010997:Pleural Neoplasms / Q000209:etiology*; D018570:Risk Assessment
D002273:Carcinogens; D001194:Asbestos