For the first 90 days after the Palisades and Eaton fires in January, the number of patients in the emergency room at Cedars-Sinai Medical Center was unusual.
The number of hospital visits due to heart attacks was 46% higher than the number of cases that typically occurred during the same period over the previous seven years. Hospital visits for respiratory illnesses increased by 24%. And abnormal blood test results increased by 118%.
These findings were reported in the Journal of the American College of Cardiology published Wednesday. This study is part of documenting the long-term health effects of fires and joins several recent papers documenting the physical harm caused by disasters.
While other wildfires in the United States have consumed more acres and claimed more lives, the Palisades and Eaton fires were uniquely dangerous to human health because they burned an unusual mix of trees, brush, and organic matter from normal wildfires, as well as a toxic stew of cars, batteries, plastics, electronics, and other man-made materials.
The paper’s authors say there is no precedent for such a situation in which so many people were exposed to this type of smoke.
“Los Angeles has had wildfires before and will continue to have wildfires, but the Eaton and Palisades fires were unique in their size, scale, and sheer volume of material burned,” said Dr. Joseph Ebinger, a cardiologist at Cedars-Sinai and lead author of the study.
The researchers found no significant increase in the total number of visits to the medical center’s emergency room between January 7, when the fire occurred, and April 7. The department recorded fewer in-person visits for mental health emergencies and chronic conditions during this period compared to the same period in previous years, said Dr. Susan Chen, director of public health research at Cedars-Sinai and lead author of the study.
Increases in hospital visits due to acute cardiovascular disease and other serious sudden illnesses accounted for the difference.
The researchers also looked at the results of blood tests taken from patients who came to the ER with serious physical symptoms without an immediate explanation, such as dizziness without dehydration or chest pain not caused by a heart attack.
Their blood tests yielded abnormal results at a rate more than twice that of previous years. These abnormal numbers cut across the spectrum of blood tests, Chen said. “It could be electrolyte disturbances, changes in protein levels, changes in markers of kidney or liver function.”
Because the rate of abnormal test results remained constant over the three-month period, the researchers concluded that exposure to fire smoke “likely caused some kind of biochemical and metabolic stress in the body, which affected not just one but many organ systems,” Chen said. “That caused different kinds of symptoms in different people.”
Joan Casey, an environmental epidemiologist at the University of Washington who was not part of the Cedars-Sinai research team, said the study found longer-lasting health effects than similar studies.
Three months is a “substantial period of time to observe an increase in visitation, as most studies focused on acute care utilization following wildfire smoke exposure find increases in visitation over a period of approximately one week,” Casey said. She found a 27% increase in outpatient visits for respiratory illnesses in the week after the fires among Kaiser Permanente Southern California members living within 12 miles of the burn zone.
“The Los Angeles fires were a very serious event that involved not just smoke, but evacuations and great stress on residents, so the effects could have lasted much longer,” Casey said.
Thirty-one people are known to have died as a direct result of injuries caused by the fire. However, researchers believe the actual death toll is significantly higher, taking into account deaths from health conditions worsened by smoke.
Journal of the American Medical Assn. The paper examined deaths caused by a variety of factors, from exposure to air pollution to medical collapse as a result of closures and evacuations.
On Tuesday, a team from Stanford University announced that 14 people had died of unexplained causes due to exposure to smoke from the fires.
Wildfires are a major source of particulate pollution, and the particles are smaller than 2.5 microns in diameter, small enough to pass through the barrier that separates blood from the brain and the outer branches of the lungs.
Compared to other sources, wildfire smoke contains a high proportion of ultrafine particles so small that they can penetrate the brain after inhalation, Casey told the Times. Smoke has been linked to a variety of health problems, including dementia, cancer, and cardiovascular failure.
The number of wildfires has increased in Western states over the past decade, necessitating improvements under the Clean Air Act and other pollution control measures.
