Lung Function in Royal Naval Firefighting Instructors

Abstract A four phase investigation into the effects of Royal Naval firefighting training on pulmonary function was carried out between 1979 and 1984. Phases I and II, reported elsewhere, failed to demonstrate changes in the lung function either in instructors, as measured by forced spirometry and transfer factor, over a one month period, or trainees, as measured by forced spirometry, during a one day fire-fighting course. This paper describes the results of phase III in which further lung function data was gathered from the instructors, at six monthly intervals, over two years. Multiple regression analysis of the data indicated that smoke exposure had a significant effect on the transfer factor (T1), flow at 75% of the forced vital capacity (FEF75), and the ratio of the forced expiratory volume in one second to the forced vital capacity (FEV1/FVC%). The decrements observed were many times those predicted for normal ageing. Analysis of data collected on instructors who had left the school in the previous twelve months failed to reveal any significant improvement in these three measurements. A later follow up study conducted 3 to 5 years after instructors had left the school (Phase IV) showed significant improvements in T1 and FEF75 when related to the first readings after leaving the school. The changes observed are confounded by the high incidence of cigarette smokers amongst the instructors.