A hidden wildfire pollutant causes thousands of excess deaths per year, satellite data shows

When you think of air pollution from wildfires, you probably picture the thick plumes of smoke and ash that waft into the atmosphere during a blaze. And if you've lived in an area that’s been enveloped by these emissions, you know to stay inside or wear a mask when the light tints red and gets hazy. But this thick cloud isn't the only component of wildfire smoke that carries a health risk. …