Protecting Public Health and the Environment.
Particulate matter, or PM, is the term for small particles found in the air including dust, dirt, soot, smoke, and liquid droplets. Particles can be suspended in the air for long periods of time. Some particles are large or dark enough to be seen as soot or smoke. Others are so small that individually they can only be detected with an electron microscope. Some particles are directly emitted into the air while others are formed in the air through chemical reactions. Sources of PM include cars, trucks, buses, factories, construction sites, tilled fields, unpaved roads, construction, wood burning, agricultural burning, wildfires, prescribed fires, and natural windblown dust.
Particulate matter is a criteria pollutant that comes in a wide range of sizes. Particles less than 10 micrometers in diameter tend to pose the greatest health concern because they can be inhaled into and accumulate in the respiratory system. Particles less than 2.5 micrometers in diameter are referred to as "fine" particles. Sources of fine particles include all types of combustion (motor vehicles, power plants, wood burning, etc.) and some industrial processes. Particles with diameters between 2.5 and 10 micrometers are referred to as "coarse." Sources of coarse particles include crushing or grinding operations and dust from paved or unpaved roads.
Both fine and coarse particles can accumulate in the respiratory system and are associated with numerous health effects. Coarse particles can aggravate respiratory conditions such as asthma. Exposure to fine particles is associated with several serious health effects, including premature death. Adverse health effects have been associated with exposures to PM over both short periods (such as a day) and longer periods (a year or more).
Air Quality Toxics AnalystDr. Carl BrownDEQ State OfficeAir Quality Division1440 N. HiltonBoise, ID 83706(208) email@example.com
Fine Particulate Matter (PM 2.5): How Particulate Pollution Affects Our View, Our Health, and Air Quality
Healthy Air, Healthy Idahoans
EPA Guide to Particulate Matter
National Ambient Air Quality Standards (NAAQS)