Article Text
Abstract
Objectives To evaluate the association between lung cancer and cleaning-related exposures.
Methods Two case-control studies conducted in Montreal to explore occupational associations with cancer included 2016 lung cancer cases and 2001 population controls. Occupational exposure to several agents was assessed using a combination of subject-reported job history and expert assessment. Participants also provided information on personal characteristics such as smoking and medical history. Using multivariate logistic regression analyses, we evaluated the associations between lung cancer and employment in 12 cleaning-related occupations, and exposure to eight chemicals related to cleaning products. For the most recent study, we analysed the effect of cleaning agents on lung cancer risk separately for asthmatics and non-asthmatics.
Results The general pattern of results was similar in both studies. Pooling the studies, we found no increased risk of lung cancer for cleaning-related occupations (odds ratio and 95% confidence interval (OR) for “ever employed in any cleaning-related occupation”: 1.0; 0.8–1.1) as compared to never cleaners. Among chemical exposures, we found a negative association of lung cancer with any occupational exposure to cleaning agents (OR: 0.9; 0.7–1.0), and biocides (0.8; 0.7–1.0). In a secondary analysis, restricting to subjects with a history of asthma, the OR between lung cancer and long duration employment in a cleaning-related occupation was 2.1 (0.9 to 5.0). The OR of lung cancer and cleaning agents was also higher, yet non-significant, among asthmatics (1.5; 0.8–2.8) than among non-asthmatics (0.9; 0.7–1.1).
Conclusions People employed in cleaning-related occupations or who had worked with cleaning agents had no increased risk of lung cancer. There was a suggestion that this overall result masked a possible increased risk of lung cancer among asthmatics with cleaning-related exposures and/or occupations.