Particulate Matter or PM comes in many different sizes. PM 2.5 is particulate matter that is 2.5 microns in size. The diagram below gives some perspective on just how big, or small, that really is.
Several Sources of PM 2.5
The main source of PM 2.5 here in Gilbert is wood burning fire places. It's nice to cozy up on a cold day in front of the fireplace and it's a nice tradition to light up the fire place during the holidays.
Unfortunately the particulate matter that comes from wood burning can cause pollution that the human lungs can't process, the particles can even make it into your blood stream!
For this reason, during certain weather patterns the State and Maricopa County issue "No Burn" days. During these days, people are prohibited from burning unless a fireplace/wood stove is the sole source of heat or you are preparing food, like on a BBQ.
Check out Clean Air Make More to see if it a No Burn Day before you light up that fireplace or chiminey. You can even download a free widget for your desktop that will tell you when it is a no burn day!
If you see someone burning on a no burn day, please call Maricopa County Air Quality at 602-372-2703.