Background: Epidemiological studies have shown an association between cleaning work and asthma, but the risk factors are uncertain. The aim of this study was to assess the risk of asthma in women employed in domestic cleaning.
Methods: A cross sectional study was conducted in 4521 women aged 30 to 65 years. Information on respiratory symptoms and cleaning work history was obtained using a postal questionnaire with telephone follow up. Asthma was defined as reported symptoms in the last year or current use of drugs to treat asthma. Odds ratios (OR) with 95% confidence intervals (CI) for asthma in different cleaning groups were estimated using adjusted unconditional logistic regression models.
Results: 593 women (13%) were currently employed in domestic cleaning work. Asthma was more prevalent in this group than in women who had never worked in cleaning (OR 1.46 (95% CI, 1.10 to 1.92)). Former domestic cleaning work was reported by 1170 women (26%), and was strongly associated with asthma (OR 2.09 (1.70 to 2.57)). Current and former non-domestic cleaning work was not significantly associated with asthma. Consistent results were obtained for other respiratory symptoms. Twenty five per cent of the asthma cases in the study population were attributable to domestic cleaning work.
Conclusions: Employment in domestic cleaning may induce or aggravate asthma. This study suggests that domestic cleaning work has an important public health impact, probably involving not only professional cleaners but also people undertaking cleaning tasks at home.