Occupational asthma in professional cleaning work: a clinical study

Background Several epidemiological studies have reported an increased risk of asthma among professional cleaners. To date, however, no analysis of large patient series from clinic of occupational medicine has been published. Aims To describe the cases of occupational asthma (OA) diagnosed at the Finnish Institute of Occupational Health (FIOH) during the period 1994-2004 in workers employed in professional cleaning work. Methods OA was diagnosed according to patient history, lung function examinations and specific challenge tests with measurements of the forced expiratory volume in 1 second and peak expiratory flow values. Results Our series comprised 20 patients, all female, with a mean age of 48.8 years (range 27-60 years). The mean duration of cleaning work before the onset of the respiratory symptoms was 14.3 years (range 1-36 years), and the mean duration of cleaning work before the FIOH examinations was 18.6 years (range 3-38 years). OA was triggered by chemicals in 9 cases (45%) and by moulds in 11 cases (55%). The chemicals were cleaning chemicals (wax-removing substances containing ethanolamines in five cases and a cleaning agent containing chloramine-T in one case) and chemicals used in the industrial processes at workplaces (three cases). Of the moulds, the most frequently associated with OA was Aspergillus fumigatus (nine cases). Conclusions OA was attributed not only to cleaning chemicals but also to other chemicals used in work environments. Moulds are presented as a new cause of OA in cleaners.