New research shows that exposure to air pollution caused by wildfires could increase the risk for acute heart incidents such as cardiac arrest.

A new study published in the Journal of the American Heart Association on Wednesday linked cardiac arrests, heart attacks and other cardiovascular “events” to wildfire smoke.

Air pollution from wildfires has long been linked to respiratory problems such as asthma, but evidence of an association between wildfire smoke exposure and adverse effects on the heart has been “inconsistent,” study author Anjali Haikerwal said in a statement after the findings were released on Wednesday.

In the study, scientists researched the association between wildfire-related “particulate pollutant” exposure and the risk of heart-related incidents in Victoria, Australia in December 2006 and January 2007.

At that time, smoke from wildfires travelled to surrounding Australian cities. On most days, the smoke also reached levels of particulate pollution that exceeded air quality limits.

After examining particles smaller than 2.5 thousandths of a millimetre in diameter, researchers found an increase in particulate concentration over two days during the wildfires.

Comparing the particle matter data to Victoria’s health registry data over the same period, the researchers found:

  • A nearly 7 per cent increase in “out-of-hospital cardiac arrests,” which are unexpected heart-related medical emergencies
  • More than 2 per cent increase in emergency department visits for ischemic heart disease
  • Nearly 2 per cent increase in hospitalizations for ischemic heart disease

Haikerwal said the data suggests the particles may act as a “trigger factor” for acute cardiovascular health episodes.

“During a fire, please take precautionary measures as advised by public health officials,” said Haikerwal, who is a doctoral candidate at the School of Public Health and Preventative Medicine at Monash University in Melbourne. “This is especially important for older adults who are at higher risk of adverse health effects during wildfire smoke exposure.”

She also said the medical community must understand the impact of smoke exposure, given a recent increase in frequency and intensity of wildfires around the world.

Doctors believe there may be a link between the lungs and the heart.

“So you can imagine that taking that in hour after hour. Day after day, that can potentially cause problems within the body. So inflammation within the lungs can cause inflammation in other parts of the body, and the lower oxygen levels can also cause stress to the heart,” says cardiologist Dr. Derek Exner

Wildfires in western Canada have prompted Environment Canada to issue several air quality advisories in recent weeks, as firefighters try to contain and extinguish blazes in B.C., Alberta and Saskatchewan.