An unusually high number of people developed a heart attack, lung complications, or general illness within 90 days after the start of the January 2025 wildfires in Los Angeles County, according to a new study from Cedars-Sinai Medical Center.
Investigators collected data on emergency department visits during the 90 days after the fires started, from Jan. 7 to April 7, and compared this data with emergency visit data collected during the same calendar period in the years 2018 through 2024. Although there wasn’t a significant difference in total emergency department visits during the first 90 days following the start of the wildfires in 2025 as compared with other years, the report detailed an acute increase in emergency department visits for specific conditions.
The report noted a 118% increase in visits for general illness, a 46% increase in the number of visits for heart attack, and a 24% increase in visits for pulmonary illness when compared to the average rate of these conditions diagnosed during the same time window in the past seven years.
The investigators also found that abnormal blood test results related to general illness more than doubled in the 90-day period after the wildfires compared with that period in previous years. This is a finding not previously reported after major wildfires, according to the investigators.
“Wildfires that spread into urban areas have proven to be extremely dangerous because of how quickly they move and what they burn and release into the environment,” said Dr. Susan Cheng, vice chairwoman of research affairs in the Department of Cardiology in the Smidt Heart Institute and senior author of the study, which was published in the Journal of the American College of Cardiology (JACC). “Our research suggests the Eaton and Pacific Palisades fires had an immediate effect on people’s health.”
Cheng added, “Fine particles released by wildfires can enter the body and cause injury, particularly to the heart and lungs. Stress related to the fires may also contribute to a broad range of health issues.”
Dr. Joseph Ebinger, associate professor in the Department of Cardiology and first author of the study, observed, “This study is an important step toward understanding how the Eaton and Palisades fires may have affected Angelenos’ health. We need more research to determine what we can do to mitigate any remaining risks and protect people from fire harm in the future.”
