Occupational exposures and lung cancer in New Caledonia

Our plain-English summary of Occupational exposures and lung cancer in New Caledonia, by G. Menvielle, D. Luce, J. Févotte, et al (Occupational and Environmental Medicine, 2003).

The study

• Authors: G. Menvielle, D. Luce, J. Févotte, I. Bugel, C. Salomon, P. Goldberg, M.A. Billon-Galland, M. Goldberg
• Journal: Occupational and Environmental Medicine
• Published: 2003;60(8):584-9
• Cited by: 36 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Aims: To study the associations between occupational exposures and the risk of lung cancer in New Caledonia.

Methods: All cases diagnosed between January 1993 and December 1995 (228 lung cancers) and 305 population controls were included. Detailed information on lifetime job history, smoking, and other potential risk factors was collected by interview. Occupational exposures were assessed from the questionnaires by an industrial hygienist, without knowledge of case-control status.

Results: No significant association was found with exposures related to nickel mining and refining, the main industrial activity in the territory. Among men, an excess risk of lung cancer was found for bus and truck drivers. Increased risks were also observed in men with the highest level of cumulative exposure to cleaning products and inorganic fertilisers. Exposure to field dust was associated with lung cancer risk in both sexes, and risk increased with cumulative exposure level. In some areas tremolite asbestos derived from local outcroppings was used as a whitewash. The association between exposure to field dust and lung cancer was limited to men and women exposed to this whitewash-that is, living in areas where the soil may contain tremolite.

Conclusion: This study shows several associations between occupational exposures and lung cancer. The findings suggest that exposure to tremolite fibres from cultivated fields may increase the risk of lung cancer in New Caledonia.

In plain English

This population-based case-control study in New Caledonia compared 226 lung cancer patients diagnosed 1993 to 1995 with 305 controls from electoral rolls. Using interviews on lifetime jobs and smoking, an industrial hygiene expert who did not know who had cancer rated exposure to a list of about 300 items, including products, mixtures and processes. No statistically significant association was found with nickel-industry exposures. Workplace asbestos exposure showed no association in men. Among men, odds ratios were raised for bus and truck drivers (2.7, 95% CI 1.1 to 7.0) and for the highest cumulative exposure to inorganic fertilisers (9.3, 1.5 to 55.6), household cleaning products (15.1, 1.3 to 170) and field dust (2.6, 1.0 to 7.3). Among women, field-dust exposure above the 75th centile of controls had an odds ratio of 4.0 (1.1 to 15.0). The field-dust link was stronger in people exposed to pö, a tremolite asbestos whitewash, who lived where the soil may contain tremolite. The authors concluded these results may reflect environmental asbestos exposure. They noted small numbers, possible chance findings, and that field dust could not be separated by geographic zone.

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: population-based case-control study
• Who was studied: 226 lung cancer cases (primary lung cancers diagnosed 1 January 1993 to 31 December 1995, identified from the New Caledonia Cancer Registry) and 305 population controls from electoral rolls. All were adults who had lived in the territory at least five years. There were 175 male cases and 236 male controls, and 51 female cases and 69 female controls.
• Exposure: Lifetime occupations, industries and a list of about 300 occupational exposure items, coded by an industrial hygiene expert. The items covered pure products, chemical families, mixtures and processes, including asbestos, nickel compounds, silica, diesel exhaust, pesticides, fertilisers, field dust and cleaning products. Residential exposure to pö, a whitewash containing tremolite asbestos, was also recorded.
• Main results:
  • Women, highest cumulative exposure to field dust (above the 75th centile among controls): odds ratio 4.0 (95% CI 1.1 to 15.0), 12 cases and 6 controls. Women ever exposed: 2.1 (0.8 to 5.1).
  • Women ever exposed to field dust: odds ratio 3.3 (95% CI 2.4 to 4.5) among women exposed to pö, compared with 1.7 (0.6 to 5.0) among women not exposed to pö.
  • Men, highest cumulative exposure (above the 90th centile) to inorganic fertilisers: odds ratio 9.3 (95% CI 1.5 to 55.6).
  • Men, highest cumulative exposure to household cleaning products: odds ratio 15.1 (95% CI 1.3 to 170).
  • Men, highest cumulative exposure to field dust: odds ratio 2.6 (95% CI 1.0 to 7.3). Ever/never field dust exposure in men was not significant (1.1, 0.7 to 1.9).
  • Men with field dust exposure above the 90th centile: odds ratio 5.7 (95% CI 1.1 to 29.7) among those exposed to pö, compared with 2.0 (0.5 to 7.8) among those not exposed to pö.
  • Men ever employed as motor bus, lorry and van drivers: odds ratio 2.7 (95% CI 1.1 to 7.0), 13 cases and 15 controls.
  • In men, no association and no dose-response relation was found for occupational asbestos exposure (ever/never odds ratio 0.8, 95% CI 0.5 to 1.2). The same held for arsenic, nickel compounds, PAH, diesel exhaust and pesticides.
  • No significant association was observed for exposures related to working with nickel.
• The authors' conclusion: The authors concluded that because field dust may contain tremolite in some regions of New Caledonia, the field dust findings may reflect environmental exposure to asbestos. They also identified three occupational groups with increased risk: cleaners and motor vehicle drivers among men, and farm workers among both sexes.
• Limitations the authors state:
  • Interviewers knew whether each person was a case or a control, which could have led to differential misclassification. Recall bias was also possible.
  • Shorter questionnaires, often answered by next-of-kin, gave less precise information.
  • Residual confounding cannot be excluded because some variables were coded crudely.
  • The small number of subjects hampered some analyses, especially for women, and prevented separate analyses by histological type.
  • Because many comparisons were made, some associations may be due to chance.
  • The available data did not allow field dust exposures to be distinguished by geographic zone. The authors suggested later analyses could take field location into account.
  • In women, the effects of field dust and of straw, hay or grass dust could not be distinguished.

Topics

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

Medical terms in this study, explained in our Lexicon: Occupational Exposure, Lung Cancer, New Caledonia, Cumulative Exposure, Tremolite, Whitewash.

Related studies

• Assessment of environmental and domestic exposure to tremolite in New Caledonia — D. Luce, M.A. Billon-Galland, et al. (2004)
• Environmental exposure to tremolite and respiratory cancer in New Caledonia: a case-control study — D. Luce, I. Bugel, et al. (2000)
• Pleural mesothelioma in New Caledonia: associations with environmental risk factors — F. Baumann, P. Maurizot, et al. (2011)
• Environmental mesothelioma associated with tremolite asbestos: lessons from the experiences of Turkey, Greece, Corsica, New Caledonia and Cyprus — S.H. Constantopoulos (2008)
• Quantifying the mediating effects of smoking and occupational exposures in the relation between education and lung cancer: the ICARE study — G. Menvielle, J.E. Franck, et al. (2016)
• Occupational exposures and risk of stomach cancer by histological type — M. Santibañez, J. Alguacil, et al. (2012)

Browse more research in Occupational and Environmental Medicine, or return to medical research.