What is Particulate Matter? And why does it matter? (Pun Intended)
Particulate matter is considered pollution by the World Health Organization (WHO) and the US Environmental Protection Agency (EPA) because exposure is associated with a range of serious negative health effects.
What is Particulate Matter (PM)?
Generally, PM comprises two kinds of microscopic particles, mineral (silica and other minerals from rock processing), and hydrocarbon and soot from diesel exhaust of industrial equipment and trucks that are heavily utilized in the quarrying industry.
PM is classified into size ranges. The PM of interest in terms of health risks are those that are very small, invisible to the naked eye, and are referred to as PM2.5 and PM10. PM2.5 comprises particles ~2.5 micrometers in size, PM10 comprises particles ~10 micrometers in size. PM2.5 and PM10 are invisible to the naked eye, and are easily carried in wind currents, can remain airborne for long periods of time, and can be carried up to 30 miles (PM10) or hundreds of miles (PM2.5) from the source. Source: What is Particulate Matter
Sources of PM
These particles come in many sizes and shapes and can be made up of hundreds of different chemicals. Some are emitted directly from a source, such as construction sites, unpaved roads, fields, smokestacks or fires. Most particles form in the atmosphere as a result of complex reactions of chemicals such as sulfur dioxide and nitrogen oxides, which are pollutants emitted from power plants, industries and automobiles.
What are the Harmful Effects of PM?
Particulate matter contains microscopic solids or liquid droplets that are so small that they can be inhaled and cause serious health problems. Some particles less than 10 micrometers in diameter can get deep into your lungs and some may even get into your bloodstream. Of these, particles less than 2.5 micrometers in diameter, also known as fine particles or PM2.5, pose the greatest risk to health.
Fine particles are also the main cause of reduced visibility (haze) in parts of the United States, including many of our treasured national parks and wilderness areas.
