What is soot (fine particles)?
Soot (fine particles) are teeny, tiny pieces of matter. In fact, they are about 30 times smaller than a human hair! For you "kno-it-alls" out there, the scientific name for soot is PM 2.5.

How is soot created?
Soot is released into the air when fuels like coal, natural gas, gasoline and diesel motor vehicle fuel, oil and wood are burned.

Is there a soot season?
No. Soot is a problem year-round. Sometimes soot levels can even be higher than smog levels in the summer! Soot levels tend to be higher in winter months. Why? People tend to burn wood in the fireplaces and idle their cars more often in the winter than in the summer. That means that more fine particles are floating in the air.