Wildfire Fine Particles May Cause Underestimated Mortality Risks by 93%

A recent study conducted by the Barcelona Institute for Global Health (ISGlobal) reveals that exposure to fine particles (PM2.5) from wildfires significantly increases the risk of mortality, potentially by a far greater extent than previously estimated. Analyzing data from the EARLY-ADAPT project, which includes daily death records across 654 European regions covering over 500 million people, researchers found that wildfire-related PM2.5 could be responsible for an average of 535 premature deaths annually in Europe. Notably, traditional estimates that treat all PM2.5 sources equally likely underestimate wildfire-related deaths by about 93%, meaning the actual impact could be nearly 14 times higher than previous calculations.

The study examined the short-term effects of wildfire smoke on all-cause, respiratory, and cardiovascular mortality. Results demonstrated that for each 1 µg/m³ increase in wildfire-derived PM2.5, there was a 0.7% rise in overall mortality, a 1% increase in respiratory deaths, and a 0.9% uptick in cardiovascular deaths within a week of exposure. Previous research suggested that wildfire PM2.5 particles are up to ten times more harmful than traffic-related particles, emphasizing the need for specific risk assessments tailored to wildfire pollution.

This discrepancy in mortality estimates underscores the importance of considering the source of fine particles in health risk evaluations. Failing to differentiate wildfire PM2.5 from other sources underestimates the true health burden, particularly as climate change contributes to increased wildfire frequency and severity. Anna Alari, a lead researcher at ISGlobal, emphasizes that better estimations of wildfire-related mortality are essential for public health strategies in the face of rising climate crisis-induced wildfires.

Regional variations were also observed, with countries like Bulgaria, Romania, Hungary, and Serbia experiencing higher mortality impacts, whereas some regions in Portugal and Spain showed weaker associations, possibly due to different wildfire management strategies. Further research is needed to understand these regional differences and improve global risk assessments.

This study highlights the urgent need to refine our understanding of how wildfire smoke impacts health and to adapt policies accordingly to mitigate these risks in an era of intensifying climate change.