Lung function in West Sussex firemen: a four year study.

Although firefighting is a hazardous occupation, published evidence of long-term lung damage in firemen is inconsistent. A group of 96 men from the West Sussex Fire Brigade, which covers a simi-rural, semi-urban area, were followed up for between one and four years. They included 31 non-smokers, 40 smokers, and 25 ex-smokers. After four years 12 firemen had been lost to the study. A control group of 69 volunteers, consisting of non-smoking men from various other occupations, were followed up in parallel. Lung function tests, covering a wider range than has been previously used in similar studies, were repeated six monthly for two years and annually for a further two years. The results were expressed in terms of the rate of change with time of the lung function variables. Many of the variables deteriorated in both firemen and controls, but the rate of deterioration was greater in the controls than the firemen for vital capacity, ratio of residual volume to total lung capacity, FEV1, FVC, peak expiratory flow (PEF), flow at 50% and 25% remaining vital capacity (V50 and V25 respectively), and airways resistance (Raw). With respect to PEF, V50, V25, and Raw the control subjects deteriorated more rapidly even than the smokers and ex-smokers among the firemen. Alveolar mixing efficiency (AME), a measure of small airways function, did not change significantly over the study period in any group. Non-smoking firemen had the highest mean value of AME, decreasing through ex-smokers, controls, and smokers. We conclude that these results show no evidence of chronic lung damage in West Sussex firemen; indeed, the firemen as a group show a lower rate of deterioration of lung function with age than do the control subjects. This is attributed to the selection of fit men for the service, continued physical training, and the regular use of breathing apparatus.