Exposure to ultrafine particles may increase firefighters’ risk of developing coronary heart disease, according to a study published this month in the Journal of Occupational and Environmental Medicine.
Researchers at the University of Cincinnati measured levels of breathable particles during various stages of fire and found that ultrafine particles — those measuring less than 0.1 micron — account for 70 percent of particles in all fires, a study abstract said.
Researchers warned the risk of ultrafine particle exposure may be highest during the overhaul stage of firefighting (when the fire has been extinguished and firefighters work to ensure it does not reignite) because many firefighters remove respiratory protection, believing the exposure risk no longer exists.
According to the study abstract, coronary events are the primary killer of firefighters during fire suppression and cause nearly one-half of all on-duty deaths.



