Wildfire Smoke Chokes Cities Hundreds of Miles From Flames

Scientists are racing to understand how wildfire smoke harms human health as fire seasons grow longer and more intense. In Toronto, more than 1,000 kilometers from the fires burning in northern Ontario’s forests, the sky turned a deep orange. The air filled with fine particles of soot and ash. Erin O’Connor, who runs the emergency department at University Health Network, said the smell was so strong it felt like standing beside a campfire. “It really hit you in the face as soon as you walked outside,” O’Connor said. “As the days progressed, it was like that everywhere. It seemed even inside you could smell that burning.” Inside Toronto General Hospital, air filters kept patients safe from the worst fumes. But outside, O’Connor saw a rise in people coming in with allergies and shortness of breath. The exact link between smoke exposure and death remains unclear. Researchers are now working to untangle how these tiny particles affect the body over time. What is clear, experts say, is that more fire weather means more people breathing dangerous air—even far from the flames.