S105 Respiratory symptoms, lung function and sensitisation across different exposure groups of british woodworkers

Background Wood dust is a leading cause of occupational asthma (OA) in the UK, with over 2 00 000 people exposed annually. There have been no recent studies examining respiratory health in British woodworkers. Aim We surveyed British woodworkers to examine how respiratory symptoms, airway inflammation, lung function and sensitisation relate to wood dust exposure. Methods British woodworkers were recruited to a cross-sectional study. All workers underwent a validated respiratory symptom questionnaire, job history and exposure measurement. Spirometry and fractional exhaled nitric oxide (FE NO ) were recorded to American Thoracic Society (ATS) standards. Blood was taken for total and specific IgE to hard and soft wood. Results 269 workers participated (Table 1). Most were men (n=261, 97%), with a mean age of 42.4 years (SD 12.6) and 18.9 (12.8) years woodworking. Mean current wood dust exposure was 1.9 mg/m 3 (SD 0.9, IQR 1.4). Current asthma symptoms (CAS, defined as wheezing, nocturnal chest tightness, exertional/nocturnal/resting breathlessness, or asthma medication use within the last 12 months) were common, reported by 123 (46%). Work-related respiratory symptoms were less common, reported by 29 (11%). Forty one (18%) people had a FE NO ≥40 ppb. Only one worker had a positive IgE to soft wood. Ten (4%) had an FEV 1 /FVC less than the lower limit of normal ( NO ≥40 ppb (OR 3.59, 95% CI 1.09–11.77). However, there was no clear exposure response relationship when looking at percent predicted FEV 1 or FVC (for FEV 1 β=0.05, p=0.41). Conclusion CAS are common among British woodworkers, reported by nearly half. One fifth fulfilled BTS criteria for high FE NO despite low sensitisation rates. The highest exposed were at lower risk for WRRS, suggesting a healthy worker effect. No clear relationship between exposure and lung function was identified. Mechanisms for asthma among woodworkers may not be IgE mediated, and longitudinal studies are needed to clarify the exposure response relationship.