A recent study published in The Lancet Planetary Health reveals that wildfire smoke is 14 times more deadly than previous estimates suggested, significantly increasing the known health risks of wildfire pollutants.

Research shows that the toxicity of wildfire PM2.5 particles is greater than that of particles from other sources like traffic, posing a higher health risk for the same amount of particulate matter.

The study indicates that wildfire smoke's impact on human health has been severely underestimated, with death tolls potentially being 93% higher than previously thought.

Using data from the EARLY-ADAPT project across 654 regions in 32 European countries from 2004 to 2022, the study accounted for deaths within seven days of exposure to better capture delayed health effects.

Between 2004 and 2022, wildfire-related PM2.5 caused an average of 535 deaths annually in Europe, vastly exceeding earlier estimates of 38 deaths per year, with most deaths linked to cardiovascular and respiratory diseases.

In 2025, wildfires in southern Europe burned over 895,000 hectares, producing more than twice the usual amount of PM2.5 for this time of year over the past two decades, contributing to increased mortality.

As climate change leads to longer and more intense wildfire seasons, exposure to wildfire smoke is expected to rise, emphasizing the need to improve mortality estimates and health tracking.

Wildfire smoke has been associated with increased short-term mortality, with each 1 microgram per cubic meter increase in PM2.5 linked to a 0.7% rise in all-cause mortality, and even higher increases in respiratory and cardiovascular deaths.

The health impacts of wildfire smoke extend well beyond fire sites, affecting populations far away and complicating efforts to accurately assess and respond to the true risks.

Experts warn that climate change-induced extreme weather and increasing wildfires will likely lead to greater health risks across Europe in the future.

Indoor air pollution from wildfires affects over 1 billion people annually, with air purifiers being an effective but costly mitigation measure.

The study faces limitations, including challenges in measuring individual exposure variability and distinguishing wildfire PM2.5 effects from ozone.