For the research, Anjali Haikerwal, the study author and a doctoral candidate at the School of Public Health and Preventive Medicine, examined the relationship between wildfire-related pollution levels and heart conditions in Victoria, Australia, during a two-month period when severe wildfires burned.

Particulate matter that wildfire smoke consists of is less than 2.5 thousandths of a mm in diameter – which is not visible to the naked eye and can cause health problems if inhaled. These rates were significantly higher than those before the wildfires in Victoria.

Researchers then used data from the Victorian Ambulance Cardiac Arrest Registry from Ambulance Victoria and data from the Department of Health and Human Services.

Wildfire smoke is the largest source of PM2.5 air pollution.

Researchers say that while there have been quite a few studies that look at association between wildfire smoke and respiratory problems, few have looked at an association between wildfire smoke exposure and heart problems.

They found that for an increase from the 25th to 75th percentile in particulate concentration over two days, after adjusting for temperature and humidity, there was a 2 percent increase in emergency department visits for acute cardiac events and a 1.86 increase in hospitalizations for acute cardiac events, with a stronger association in women and people 65 and older.

While the researchers only found an association between pollution levels and heart issues, they said the tiny particles of air pollution from the fires are the culprit.

“These particles may act as a trigger factor for acute cardiovascular health events”, Haikerwal states.

Furthermore, Haikerwal also advises that the medical community needs to understand the impact of exposure to smoke, particularly in reference to what this study has determined.

The Centers for Disease Control and Prevention (CDC) offer a number of tips for protecting yourself from the dangers of wildfire smoke.

Although the study was purely observational and did not establish cause and effect, Haikerwal said the results might influence public health messages in areas at risk for wildfires, adding that it’s advisable to “stay indoors”, “maintain medication” and seek immediate assistance if you find yourself anxious at any point in time. “This is especially important for older adults who are at higher risk of adverse health effects during wildfire smoke exposure”.