Longitudinal lung function in urban firefighters: A group‐based multi‐trajectory modelling approach

Abstract

Background and Objective: Urban firefighters are routinely exposed to both physical and chemical hazards that can negatively impact lung health, but it is unclear if firefighters experience accelerated decline in spirometry parameters due to chronic exposure and acute insults. This study aimed to describe sub-groups of firefighters with differing spirometry trajectories and examine the relationship between the identified trajectories and demographic, lifestyle and occupational characteristics. Methods: Data from six waves of the Respiratory Function Measurement and Surveillance for South Australian Metropolitan Fire Service Study (2007Study ( -2019 were used to identify spirometry parameter z-score trajectories, using group-based multitrajectory modelling (GBMTM). Analysis of variance and chi-square statistics were used to assess trajectory group differences in baseline self-reported demographic, lifestyle and occupational characteristics. Results: In the 669 included firefighters, we identified five trajectories for the combination of Forced Expiratory Volume in the first second z-score (FEV 1 z), Forced Vital Capacity z-score (FVCz) and the ratio of FEV 1 and FVC z-score (FEV 1 /FVCz). There were three stable trajectories of low, average and very high lung function and two declining trajectories of average and high lung function. Analysis of subgroup characteristics revealed no significant differences between expected and actual group proportions for the occupational characteristics of years of service and respiratory protection use. Significant differences were seen in respiratory health and body mass index. Conclusion: GBMTM defined distinct, plausible spirometry trajectory sub-groups. Firefighter longitudinal spirometry trajectory group membership was associated with BMI and respiratory disease or symptoms but not with self-reported smoking history or occupational factors.

Knowledge of Infection Prevention and Control and Practice Behaviors among Career and Volunteer Firefighters in Rural Communities

“…Western Kentucky University (WKU) Center for Environmental and Workplace Health (CEWH) research team previously identified a concern for negative health outcomes with firefighter exposures to work-related toxic substances and behaviors on management of turnout gears (coats and pants) [13][14][15]. Overall, there is limited literature on firefighters' exposure to biological contaminants; most of the previous studies are limited to chemical exposures [14][15][16] and were conducted in urban areas [17][18][19]. Therefore, the purpose of this study was to compare career and volunteer firefighters' knowledge and practice behaviors on infection transmission in the dayroom and during emergency runs.…”

Trajectories of lung function in urban firefighters

“…In Australia in 2020–2021, there were 17,459 paid firefighters, but many more 144,159 volunteer firefighters 9 . Only 2% of participants in the South Australian study were female 6 . In another cohort study, covering the majority of Australian firefighters (but not South Australia or Tasmania), 4% of full‐time paid, 8% of part‐time paid and 23% of volunteers were women 8 .…”

“…9 Only 2% of participants in the South Australian study were female. 6 In another cohort study, covering the majority of Australian firefighters (but not South Australia or Tasmania), 4% of full-time paid, 8% of part-time paid and 23% of volunteers were women. 8 Given that women generally have smaller lungs than men and might be more susceptible to the effects of smoke, further research on female firefighters is required.…”

“…In a recent publication in Respirology, Pendergrast et al have applied GBTM to respiratory function measurements and surveillance for the metropolitan fire service in the state of South Australia. 6 From the data for 669 urban firefighters, the authors identified five trajectories for FEV 1 , FVC and FEV 1 /FVC: three stable trajectories of low, average and very high lung function, and two declining trajectories of average and high lung function. Trajectory group membership was associated with body mass index and respiratory diseases or symptoms, but not self-reported tobacco smoking, nor occupational factors such as years of service or use of respiratory protection.…”

“…In a recent publication in Respirology, Pendergrast et al have applied GBTM to respiratory function measurements and surveillance for the metropolitan fire service in the state of South Australia 6 . From the data for 669 urban firefighters, the authors identified five trajectories for FEV 1 , FVC and FEV 1 /FVC: three stable trajectories of low, average and very high lung function, and two declining trajectories of average and high lung function.…”