Air quality levels in parts of the U.S. plunge as Canada wildfires rage

Air pollution from wildfire smoke has become a significant health risk in the U.S., and it is growing worse. Stanford University researchers found that the number of people who experienced at least one day with unhealthy air quality because of smoke rose by 27 times over the last decade.

Small particles in smoke that are less than 2.5 micrometers in diameter — about 4% of the diameter of an average human hair — are of particular concern to air quality researchers. “These are the particles that are small enough to breathe in and can cause cardiovascular issues,” said Brett Palm, a scientist at the National Center for Atmospheric Research in Boulder, Colorado.

Read more at NBC News; June 5, 2023