Lung function and health status in metropolitan fire-fighters compared to general population controls

Purpose: To assess health status of South Australian (SA) metropolitan fire-fighters in terms of lung function and health-related quality of life, compare these with general population controls, and explore associations between fire-fighters' self-reported occupational exposure and health status. Methods: The study was a cross-sectional comparison of (respiratory) health indices between 501 fire-fighters and 1,324 general population controls taken from the North West Adelaide Health Study (NWAHS). All were men aged 21 to 61. Measurements included spirometry (i.e., forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), mid-expiratory flow (FEF _25-75) and the Short Form 36 (SF-36) health-related quality of life questionnaire. Results: Health status in the fire-fighters was generally better than in NWAHS controls. Mean % predicted FEV₁ and FVC were 103.4% [SD 12.1] versus 89.5% [13.7] and 110.0% [11.6] versus 88.5% [12.5] (both p < 0.001 in linear regression analysis, adjusted for age, smoking, BMI, and FEV₁ % predicted). FEV₁/FVC and FEF_25-75 were significantly lower in the fire-fighters (p < 0.003). A total of 93 (18.6%) fire-fighters and 82 (6.2%) controls had an FEV₁/FVC < 70% (p < 0.001). The SF-36 Mental Health scale was the only scale on which fire-fighters had a lower mean score (p = 0.009), but none of the SF-36 scales showed clinically meaningful differences between the cohorts. Fire-fighters exposed > 6 h/week to dust, smoke, and fire showed lower FEV₁, FEV ₁ % predicted, and FVC values compared to those who were less exposed (p < 0.05). Conclusions: Male metropolitan fire-fighters showed better general health, better lung health, and similar mental health compared to general population controls. The high rate of fire-fighters with FEV ₁/FVC values below the recommended cut-point for airflow obstruction illustrates the inappropriateness of this clinical cut-point for use in populations preselected on their physical fitness. The observed dose-effect relationship between self-reported occupational exposure and fire-fighters' lung function warrants further investigation.