Air Quality: Particulate Matter

Whether you can see it, or not, the air around us carries dust particles. The particles can range in size from a grain of sand down to molecular dimensions and be of wide-ranging compositions.

Particulates originate from many different industrial and transportation points, as well as from natural sources. Similar to ozone, particulates can be carried on prevailing winds over great distances. For scientific purposes, airborne particulate matter is classified according to its aerodynamic size. The SLEA has focused on the monitoring of fine particulates, or respirable particulates (PM2.5), which are 2.5 microns or less in diameter and are capable of penetrating deep into a person’s respiratory system. PM2.5 has also been added to the Ontario Air Quality Index Program, reaffirming the connection of fine particles to the formation of smog and its associated human health concerns. The Tapered Element Oscillating Microbalance Method for real-time continuous measurement of PM2.5 is relatively new. Having been developed and refined over the past 12 years, the method is used by Environment Canada and the Ontario Ministry of the Environment.

See the most recent Progress Review Technical Summary for details on Particulate Matter.