Acute and chronic effects of fire fighting on pulmonary function.

The acute and chronic effects of fire fighting on pulmonary function were studied in 54 fire fighters from Connecticut, 32 smokers and 22 nonsmokers. Baseline studies of maximum expiratory flow-volume curves while breathing air and a mixture of 80 percent helium and 20 percent oxygen revealed obstruction of the small airways in 35 percent (nine) of 26 smokers and 13 percent (two) of 15 nonsmokers. Cigarette smoking appears to be a major contributor to obstruction of the airways in fire fighters. In the nonsmoking group, disease of the small airways was present only in fire fighters with at least 25 years of fire fighting, and none of them had respiratory complaints. In seven fire fighters retested immediately following mild exposure to a fire in a building, no significant changes in pulmonary function were noted. One fire fighter trapped in a fire in a basement had a high level of carboxyhemoglobin (42 percent) and developed a severe obstructive ventilatory defect which persists 2 1/2 years after the fire. The significance of disease of the small airways in fire fighters with chronic exposure remains to be elucidated with long-term studies; however, acute significant exposure may be associated with irreversible pulmonary injury in fire fighters.