Wildfire smoke health and mortality impacts

Research has increasingly linked wildfire smoke exposure to severe public health consequences, including elevated cancer risks and rising mortality rates.

A Harvard study published in The Laryngoscope identified a connection between wildfire smoke and an increased risk of head and neck cancers. The study found that smoke exposure was associated with a 6% increase in these cancer risks, a figure that rose to 41% for individuals exposed to wildfire pollution on an annual basis. Researchers noted that fine particulate matter (PM2.5) in the smoke may be up to ten times more harmful than vehicle emissions.

Concurrently, a report in The Lancet highlighted a significant rise in deaths attributed to wildfire smoke in Canada and Ireland, driven by climate change. In Canada, annual deaths linked to smoke rose from an average of 1,050 between 2003 and 2012 to approximately 4,000 between 2021 and 2025. In Ireland, smoke-related fatalities reached record levels in 2025 with 249 deaths, following a period where annual averages were significantly lower.