As a series of massive fires continues to blaze through the Los Angeles area, blanketing neighborhoods with smoke and forcing thousands of people to evacuate their homes, air quality remains unhealthy throughout many parts of the county.
Wildfire smoke is a mixture of water vapor, gases, and microscopic particles known as particulate matter. The smallest of these particles, known as PM2.5 because they have a diameter of less than 2.5 micrometers, pose the most danger to human health. They can lodge deep in the lungs and sometimes enter the bloodstream. Earlier this week, PM2.5 around Los Angeles rose to “hazardous” levels, the highest warning on the