U.S. Climate Resilience Toolkit

This satellite image shows smoke from forest fires in Quebec, Canada, during July 2002 (red circles). The fires resulted in up to a 30-fold increase in the concentration of fine particles in the air in Baltimore, Maryland, a city nearly a thousand miles downwind. These fine particles—which are extremely harmful to human health—not only affect outdoor air quality, but also penetrate indoors, increasing the long-distance effects of fires on health.