Inhaled smoke, pollutants, volatile organic compounds, and polycyclic aromatic hydrocarbons were linked to negative respiratory and cardiovascular consequences in firefighters, making them a unique group with personal and occupational risk factors for cardiovascular disease.  A number of these exposures were linked to the onset of atrial fibrillation. For a study, the researchers sought to find a link between atrial fibrillation and work exposure in firemen. Between October 2018 and December 2019, a cross-sectional survey was conducted. Data were collected electronically and stored in a secure REDCap database.  Members of at least 1 of 5 pre-selected professional organizations were polled via electronic connections provided by the organizations. The number of fires battled each year was used as a proxy for occupational exposure, as was self-reported cardiovascular illness.  The poll was completed by 10,860 active firemen, 93.5% of whom were men, and 95.5% were about the age less than or equal to 60.  Firefighters who battled more fires per year had a higher risk of atrial fibrillation (0–5 fires per year 2%, 6–10 fires per year 2.3%, 11–20 fires per year 2.7%, 21–30 fires per year 3%, 31 or more fires per year 4.5%; P<0.001). According to multivariable logistic regression, a more significant number of fires fought per year was linked to a higher incidence of atrial fibrillation (odds ratio 1.14 [95% CI, 1.04–1.25]; P=0.006).  The number of fires that firefighters put out each year might increase the risk of atrial fibrillation.  To investigate causality and mechanisms, more clinical and translational research was required.