Airway symptoms among Norwegian sawmill workers at baseline of a longitudinal study

Background: Sawmill workers are exposed to wood dust, terpenes, microorganisms and resin acids. Cross-sectional studies have shown that the exposure is related to respiratory symptoms, rhino-conjunctivitis and obstructive lung diseases. Aims: To study the relationship between job type and airway symptoms in Norwegian sawmill workers. Methods: Altogether 447 employees in 11 sawmills participated (participation 90%). Respiratory symptoms, smoking status and other relevant information were recorded by questionnaire. Workers were categorized by job type. Associations between respiratory symptoms and job type, previous exposure, gender, age category, allergy, familial asthma, doctor diagnosed asthma (DDA), any household animal and smoking status, were analysed by logistic regression. Results: Mean age was 47 (SD 12) years, 91% were male and the prevalence of never, former and current smokers was 42%, 28% and 30%, respectively. Respiratory symptoms were lower in employees with administrative jobs compared to production workers. The odds ratio OR, (95% confidence interval), for having one or more respiratory, nose or eye symptom was 2.0 (1.2-3.4) for workers in departments with dry wood exposure. Dyspnea and wheeze were strongly associated with DDA and sorting of freshly cut lumber, OR 4.6 (1.1-18.9). Cough with phlegm was strongly associated with current smoking, furnace and kiln work, OR 4.8 (1.6-14.3), and dry wood exposure, OR 2.5 (1.2-5.3). Nose irritation was strongly associated with allergy and with dry wood exposure, OR 2.3 (1.3-4.1). Conclusion: The prevalence of airway symptoms differed between departments, suggesting differences in exposure. This will be subject for further study.