Respiratory Outcomes of Firefighter Exposures in the Fort McMurray Fire

Abstract

Objective: Determine effects on respiratory health of firefighters attending a catastrophic wildfire. Methods: Within the Alberta Administrative Health Database, we identified five community-based controls for each firefighter in a cohort of 1234 deployed to the 2016 Fort McMurray fire. Spirometry records were identified and a stratified sample assessed clinically. We estimated PM2.5 particles exposure. Results: Firefighters had an increased risk of asthma consultation post-fire (OR new onset asthma = 2.56; 95%CI 1.75 to 3.74). Spirometry showed decreased FEV1 and FVC with increasing exposure. In the clinical assessment, 20% had a positive MCT and 21% BWT. Those with ongoing fire-related symptoms had a higher concurrence of positive MCT and BWT (OR = 4.35; 95%CI 1.11 to 17.12). Lower diffusion capacity related to higher exposure. Conclusions: Massive exposures during a wildfire are associated with non-resolving airways damage.

The Health of Firefighters Deployed to the Fort McMurray Fire: Lessons Learnt

“…Respiratory symptoms were overall less marked with increasing time since the fire, with little relationship to estimated particulate exposure at the second follow-up, some 30 months after the start of the fire. The subgroup of 16% of firefighters reporting on-going lung or breathing problems related to the fire were drawn from those more heavily exposed and, as has been shown elsewhere ( 12 ), had an increased risk of clinically verified airways hyperreactivity and bronchial wall thickening. Mental ill-health, as reflected in the anxiety and depression scales of the HADS, showed a rather different pattern, with increased anxiety and depression with longer time since the fire.…”

“…We were fortunate also to be able to link firefighters to their administrative health record and so have some indication of their pre-fire health and how this compared to others in their community. This was particularly valuable looking at respiratory ill-health where we found an excess of asthma in firefighters pre-fire with increased numbers post-fire ( 12 ). A comparable analysis for mental ill-health, included here, was less successful in demonstrating a post-fire excess in firefighters largely, perhaps, because assessment or treatment by psychologists would not be reflected in this database (but was almost certainly part of the assessment in those with WCB compensation).…”

“…In one paper ( 8 ) we examined the relation of inflammatory markers, taken 3–4 months after the start of the fire, to both exposure and respiratory ill-health and suggested that, in the absence of external estimates of exposure, long term biomarkers might be a useful proxy. From the clinical assessment of those with ongoing respiratory problems, we suggest that the combination of airways hyperreactivity and bronchial wall thickening might be used as a marker of fire-related damage ( 12 ).…”

“…At the second follow-up participants also completed the ECHRS. Using the approach of Sunyer et al ( 18 ) we had extracted 4 factors ( 8 , 12 ) we labelled as reflecting cough, phlegm, asthma and wheeze. We also asked if they had any ongoing lung or breathing problems related to the fire.…”

“…To do that successfully we needed to rely as much as we could on objective measures of exposure and effect. We have previously given detailed results on many aspects of the study (7)(8)(9)(10)(11)(12) but here we want to consider particularly the firefighters' perceptions of their experiences and how these relate to their ongoing ill-health. We describe the evolution of respiratory symptoms with time since the fire and the nature of the respiratory conditions that do not resolve.…”