Cardiovascular health effects following exposure of human volunteers during fire extinction exercises

Maria Helena Guerra Andersen,Eva-Carina Nørskov,Peter Møller,Anne Thoustrup Saber,Ulla Vogel,Julie Elbæk Pedersen,Peter Bøgh Pedersen,Åse Marie Hansen,Anne Helene Garde,Niels Ebbehøj,Ismo Kalevi Koponen,Steffen Loft,Per Axel Clausen

doi:10.1186/s12940-017-0303-8

Abstract

BackgroundFirefighters have increased risk of cardiovascular disease and of sudden death from coronary heart disease on duty while suppressing fires. This study investigated the effect of firefighting activities, using appropriate personal protective equipment (PPE), on biomarkers of cardiovascular effects in young conscripts training to become firefighters.MethodsHealthy conscripts (n = 43) who participated in a rescue educational course for firefighting were enrolled in the study. The exposure period consisted of a three-day training course where the conscripts participated in various firefighting exercises in a constructed firehouse and flashover container. The subjects were instructed to extinguish fires of either wood or wood with electrical cords and mattresses. The exposure to particulate matter (PM) was assessed at various locations and personal exposure was assessed by portable PM samplers and urinary excretion of 1-hydroxypyrene. Cardiovascular measurements included microvascular function and heart rate variability (HRV).ResultsThe subjects were primarily exposed to PM in bystander positions, whereas self-contained breathing apparatus effectively abolished pulmonary exposure. Firefighting training was associated with elevated urinary excretion of 1-hydroxypyrene (105%, 95% CI: 52; 157%), increased body temperature, decreased microvascular function (−18%, 95% CI: -26; −9%) and altered HRV. There was no difference in cardiovascular measurements for the two types of fires.ConclusionObservations from this fire extinction training show that PM exposure mainly occurs in situations where firefighters removed the self-contained breathing apparatus. Altered cardiovascular disease endpoints after the firefighting exercise period were most likely due to complex effects from PM exposure, physical exhaustion and increased core body temperature.

Highlights

Firefighters have increased risk of cardiovascular disease and of sudden death from coronary heart disease on duty while suppressing fires
The particulate matter (PM) exposure assessment showed that the protective equipment (PPE) with the self-contained breathing apparatus very efficiently protected the conscripts from PM exposure by inhalation during fire-suppression activities
The present study showed that participation in fire extinction exercise did not cause PM exposure during firefighting using the PPE with self-contained breathing apparatus, whereas PM exposure occurred when the self-contained breathing apparatus was taken off in areas considered safe

Summary

Introduction

Firefighters have increased risk of cardiovascular disease and of sudden death from coronary heart disease on duty while suppressing fires. It has been shown that deaths from coronary heart disease were most frequent among firefighters who were actively engaged in suppressing fires, whereas those with non-emergency duties had the lowest mortality among on-duty firefighters [2]. Exercise increases the body temperature and evokes a number of hemodynamic changes, including vasodilation [7]. All, these results demonstrate an immediate and possibly transient effect of exercise and increased body temperature on the cardiovascular physiology

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