AIRWAY HYPERRESPONSIVENESS AND THE PREVALENCE OF WORK-RELATED SYMPTOMS IN WORKERS EXPOSED TO IRRITANTS

The association between exposure to airway irritants and the presence of work-related symptoms and whether this association was modified by airway hyper-responsiveness, smoking, and allergy by history was studi ed in 668 workers of synthetic fiber plants. A Dutch version of the Br itish Medical Research Council (BMRC) questionnaire with additional qu estions on allergy and work-related symptoms was used to assess sympto ms, and a standardized histamine challenge test of airway hyper-respon siveness (AHR) was employed. Work-related symptoms were defined as hav ing more than usual eye and respiratory symptoms during work. On the b asis of job titles and working department, the exposure status of all workers was characterized into seven groups: (1) reference group; (2) white collars; (3) SO2, HCl, SO(4)2-; (4) polyester vapor; (5) oil mis t and oil vapor; (6) polyamide and polyester vapor; and (7) multiple e xposure. The association between exposure groups and work-related symp tom prevalence was estimated by means of multiple logistic regression. The overall prevalence of the work-related symptoms were: cough 9%; p hlegm 6%; dyspnea 7%; wheeze 2%; eye symptoms 16%; nasal symptoms 15%. Exposure to airway irritants was significantly associated with work-r elated symptoms, independent of AHR, smoking, allergy by history, and chronic respiratory symptoms. The association of exposure group with w ork-related symptoms was stronger for subjects with AHR than for subje cts with no AHR. The association with dyspnea and/or wheeze was also s tronger for smokers than for nonsmokers and ex-smokers. In contrast, t he association between exposure and a higher prevalence of work-relate d symptoms was stronger in subjects with no history of allergy than in subjects with history of allergy. This is most likely due to the rela tively high prevalence of background symptoms in (nonexposed) allergic subjects. It is concluded that exposure to irritants in the working e nvironment might lead to respiratory symptoms, even if exposure levels are relatively low. (C) 1994 Wiley-Liss, Inc.