When wildfires burn, smoke can travel long distances and degrade air quality far away, posing risks to those breathing it. Fires burning in one state can make the air worse several states away, and wildfires in Canada can send smoke into US cities, as is happening this week, with cities in the Midwest experiencing the worst air quality in the world. Here's what to know about taking precautions against poor air quality due to wildfires, from the AP:
- What counts as bad air? The Environmental Protection Agency's Air Quality Index converts all pollutant levels into a single number. The lower the number, the better. Anything below 50 is classified as "healthy." Fifty to 100 is "moderate," while 100 to 150 is unhealthy for "sensitive groups," and anything above 150 is bad for everyone. Sensitive groups include people with asthma, lung disease, or chronic obstructive pulmonary disease, says Dr. Sanjay Sethi, chief of the division of pulmonary, critical care, and sleep medicine at the University of Buffalo medical school. "If you have heart or lung problems, then you've got to be definitely more careful," Sethi says. "I would either avoid going outside or wear an N95 or at least a dust mask."