PM 2.5 - Something You Need to Know about Air Pollution

What is PM2.5 PM2.5 refers to atmospheric particulate matter (PM) that have a diameter of less than 2.5 micrometers, which is about 3% the diameter of a human hair. PM2.5 is also known as fine particulate matter (2.5 micrometres is one 400th of a millimetre). Where Do PM2.5 Come From There are outdoor and indoor sources of fine particles. Outside, fine particles primarily come from car, truck, bus and off-road vehicle (e.g., construction equipment, snowmobile, locomotive) exhausts, other operations that involve the burning of fuels such as wood, heating oil or coal and natural sources such as forest and grass fires. Fine particles also form from the reaction of gases or droplets in the atmosphere from sources such as power plants. These chemical reactions can occur miles from the original source of the emissions. Fine particles can be carried long distances from their source, events such as wildfires or volcanic eruptions can raise fine particle concentrations hundred...