Wildfires produce huge quantities of airborne particles, also called fine particulate matter. These particles are less than 2.5 micrometers in diameter – about a tenth the size of a pollen grain.
Particles of that size, which air quality experts refer to as PM2.5, raise serious health concerns because they are tiny enough to be carried to the air sacs in the deepest parts of the lungs. From there, they can cross into the blood stream, leading to bodywide inflammation – essentially, the immune system’s fight response – which can promote or aggravate multiple chronic illnesses.
