Annals of Occupational Hygiene Advance Access originally published online on December 21, 2005
Annals of Occupational Hygiene 2006 50(3):241-248; doi:10.1093/annhyg/mei064
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© 2005 British Occupational Hygiene Society Published by Oxford University Press
Original Article |
Lung Fibre Burden in Lung Cancer Cases Employed in the Rock and Slag Wool Industry
1 International Agency for Research on Cancer, Lyon, France; 2 Health Protection Agency Centre for Infections, Colindale, London, UK; 3 Division of Materials and Minerals, Cardiff School of Engineering, Cardiff, UK; 4 Danish Cancer Society, Copenhagen, Denmark; 5 Norwegian Cancer Registry, Oslo, Norway; 6 German Cancer Research Center, Heidelberg, Germany; 7 Gentofte Hospital, Department of Pathology, Gentofte, Denmark; 8 Institute of Occupational Medicine, Edinburgh, UK and 9 IFC-National Research Council, Pisa, Italy
* Author to whom correspondence should be addressed. Gene-Environment Epidemiology Group, International Agency for Research on Cancer (IARC), 150 cours Albert-Thomas, 69008 Lyon, France. Tel.: +33-4-72738441; fax: +33-4-72738320; e-mail: boffetta{at}iarc.fr
Objectives: To evaluate the relationship between estimated exposure to man-made vitreous fibres (MMVF) and to asbestos fibres and their concentration in the lung tissue of lung cancer cases amongst MMVF production workers.
Methods: Retrospective retrieval of available lung tissue specimens was conducted following a case–control study that assessed estimated occupational exposures of MMVF workers. Fibre recovery and analysis by transmission electron microscopy (TEM) were conducted to determine fibre type, fibre dimension and numbers per gram of dry lung tissue. For cases with detailed exposure data, geometric mean (GM) concentrations were compared across the exposure categories, and regression models were used to investigate the relationship between the lung fibres and the variables of estimated exposure, with and without additional variables that may affect fibre retention.
Results: A total of 24 samples from 17 cases of lung cancer were available for analysis: MMVF were detected in all cases. Asbestos fibres were detected in 16. No difference or trend in GM MMVF concentration was observed across the estimated exposure categories. Odds ratio (OR) for MMVF g–1 dry lung was 0.5 (95% confidence interval: 0.1–2.4) for the second, and 3.5 (0.6–18.9) for the third quartile of index of average exposure to MMVF in industry, compared with the first (lowest exposed) quartile (no cases in the highest quartile).
Conclusions: No observable relationship existed between estimated exposure and directly-measured lung fibres among this sample of cases. Retrospective specimen collection, intra-individual variability in fibre concentration, effect of unknown factors on fibre retention and small sample size militated against this study providing evidence for or against a relationship between estimated exposure and lung fibre concentrations.
Keywords: epidemiology • man-made vitreous fibres • lung neoplasms • asbestos