Background: Few longitudinal studies characterize firefighters’ pulmonary function. We sought to determine whether firefighters have excessive FEV(1) decline rates compared with control subjects.
Methods: We examined serial measurements of FEV(1) from about 6 months prehire to about 5 years posthire in newly hired male, never smoking, non-Hispanic black and white firefighters, hired between 2003 and 2006, without prior respiratory disease or World Trade Center exposure. Similarly defined Emergency Medical Service (EMS) workers served as control subjects.
Results: Through June 30, 2011, 940 firefighters (82%) and 97 EMS workers (72%) who met study criteria had four or more acceptable posthire spirometries. Prehire FEV(1) % averaged higher for firefighters than EMS workers (99% vs 95%), reflecting more stringent job entry criteria. FEV(1) (adjusted for baseline age and height) declined by an average of 45 mL/y both for firefighters and EMS workers, with Fire 2 EMS decline rate differences averaging 0.2 mL/y (CI, 2 9.2 to 9.6). Four percent of each group had FEV(1) less than the lower limit of normal before hire, increasing to 7% for firefighters and 17.5% for EMS workers, but similar percentages of both groups had adjusted FEV(1) decline rates 10%. Mixed effects modeling showed a significant influence of weight gain but not baseline weight: FEV(1) declined by about 8 mL/kg gained for both groups. Adjusting for weight change, FEV(1) decline averaged 38 mL/y for firefighters and 34 mL/y for EMS workers.
Conclusions: During the first 5 years of duty, firefighters do not show greater longitudinal FEV(1) decline than EMS control subjects, and fewer of them develop abnormal lung function. Weight gain is associated with a small loss of lung function, of questionable clinical relevance in this fit and active population.