Particulate Matter

Particulate pollution comes from vehicle exhaust, smokestacks, wood burning, mining, construction activity, and agriculture and is a combination of fine solids such as dirt, soil dust, pollens, molds, ashes, soot; and aerosols chemically formed in the atmosphere from gaseous combustion by-products. Fine particles - PM 2.5 - are those less than 2.5 microns in diameter (A human hair is about 75 microns in diameter).

PM 2.5 is easily inhaled deeply into the lungs where it can be absorbed into the bloodstream or remain embedded for long periods of time. Exposure worsens asthma & causes wheezing, coughing & respiratory irritation in anyone with sensitive airways. New studies have shown that exposure triggers heart attacks, irregular heartbeats & premature death

PM 2.5 pollution can occur anytime of the year, but we tend to see high levels in the winter when inversions trap pollution in the Treasure Valley.