Wildfires tearing through North America and Europe, intensified by the climate crisis, are leaving a trail of destruction and smoke that could have health consequences lasting years, according to new research.
Current Fires Across Continents
Nearly 1,000 fires have ignited in Canada's boreal forests, forcing evacuations and sending toxic smoke into major Canadian and US cities. The smoke prompted threats from Donald Trump, who accused Canada of poisoning US air. In the US, vast lightning-sparked fires in Washington, Oregon, and Idaho have created a smoke plume so large it could reach Florida. Meanwhile, huge fires in the UK, France, and Spain have led to the evacuation of more than 250,000 people.
The climate crisis, driven by fossil fuel burning, is creating fire-prone conditions by drying soils and plants. Spanish Prime Minister Pedro Sánchez said, “The entire Iberian peninsula is suffering the effects of the climate emergency in a very specific way.”
Health Risks from Smoke
Wildfire smoke can trigger severe respiratory and cardiac problems. A recent study found that exposure to tiny particles in wildfire smoke raises hospitalization risk for older people hundreds of miles away. Study co-author Kai Chen, associate professor of epidemiology at Yale, said, “The cardiovascular toll of wildfire smoke reaches well beyond the fire lines and well beyond the day the sky turns orange.”
Long-Term Effects: Maui Study
Three years after Maui wildfires killed over 100 people and destroyed thousands of buildings, many survivors still struggle with health issues. The Maui Wildfire Exposure Study, led by University of Hawaii researchers and released Monday, found poorer lung function, higher blood pressure, and mental health challenges persist.
“The progress is real, and it should be recognized,” said Alika Maunakea, study co-director and University of Hawaii professor. “But the biological, emotional and social consequences of a disaster do not disappear on the same timeline as debris removal or reconstruction.”
Nearly half of adults in the study reported depressive symptoms, and nearly one in five had post-traumatic stress. Children and adolescents showed increased severe depressive symptoms, PTSD, higher blood pressure, and obesity. Christopher Knightsbridge, a mental health therapist in Lahaina, said, “Children may appear resilient while still carrying significant emotional and physical effects beneath the surface. Supporting children means supporting the entire family, including their housing, food security, daily routines and access to trusted care.”
Need for Ongoing Support
Researchers stress long-term monitoring and intervention are needed after major wildfires. Authorities could create “clean air centers” for smoke-affected areas. A research paper last year found a 7% increase in mortality among older people in southern California over three years due to wildfire smoke, recommending that clean air centers be activated even at low smoke levels. Lara Schwarz, environmental health scientist at UC Berkeley and lead researcher, said, “As wildfires become more frequent and severe in the context of climate change, with California being at high risk, understanding how these harmful wildfires will affect us in the long term is critical to informing better public health action and response.”
