PARTICULATE MATTER (PM)
The term ‘particulate matter’ (PM) refers to a form of pollution consisting of airbourne particles of solid or liquid matter. These particles are microscopic are designated according to the respective sizes using the micrometers [µm] as the unit. Particles with a diameter less than 10 micrometers are designated to as PM10 (otherwise referred to as course particles), with particles with a diameter less than 2.5 micrometers being designated as PM2.5 (fine particles), and those less than 1 micrometer as PM1 (ultrafine particles). To give an idea of quite how small these particles are, 1 µm is equal to 1 millionth of a meter or 1 thousandth of a millimeter and the average diameter of a human hair is about 60 µm in diameter while a grain of fine beach sand might be in the region of 90 µm in diameter. It is precisely because these particles are so small that they can cause serious health problems. While particles larger than 10 micrometers can irritate the eyes, nose, and throat, particles that are smaller than 10 micrometers can penetrate deep into the lungs and even the bloodstream and can therefore cause or aggravate health problems associated with both your lungs and heart such as heart disease, lung disease, asthma, and other respiratory diseases. Particulate matter (PM) found within the home typically include both particles of outdoor origin that have migrated indoors and particles from indoor sources. Indoor PMs are typically generated from cooking or burning including use of stoves, heaters, and fireplaces, as well as activities such as burning of candles and cigarette smoking.