Firefighters are exposed to irritating, asphyxiating toxic gases and aerosols. Previous studies indicate that this may result in acute as well as chronic lung function impairment. It is well known that inhalation of organic material can cause alveolitis. The purpose of this study was to investigate whether firefighters repeatedly exposed to fire gases and other combustion products develop inflammatory changes in the lower airways and, if so, what subtype of cells and soluble components accumulate.
Thirteen nonsmoking firefighters underwent bronchoalveolar lavage (BAL), and the results were compared to a reference group of 112 nonsmoking healthy volunteers. The firefighters showed lower recovery of instilled lavage fluid (61% vs 72%; P , 0.01) and an increase in the proportion of lymphocytes in that fluid (8.2% vs 5.7%; P , 0.05). Alveolar macrophage fluorescence, which is a sign of uptake of inhaled fluorescent material, rather than a reflection of the degree of inflammation, was increased in two firefighters. Further, the lavage fluid had higher concentrations of native fibronectin (34.6 vs 22.0 µg/L; P , 0.01) and hyaluronic acid (27.7 vs 10.0 µg/L; P , 0.05). This may indicate local cell activation, since the alveolar capillary membrane probably was intact, as indicated by an unaffected albumin concentration.
The observed changes in the deep airways are probably caused by exposure to smoke. It cannot be concluded whether these changes are permanent or are part of a natural temporary defense mechanism.