What is particle matter?
When we speak of air pollution, particles are simply small materials that can be suspended or will float in the air. A large collection of particles is called particle material or sometimes particulates. Particles can be quite large, like sand, or may be too small for us to see without a microscope. Most of the particles that we find in our cities are really very complicated mixtures of many different things. They include: • Dust blown by the wind from soil, stockpiles of building materials, industrial raw materials and products, or from the vehicles that drive over unsealed or dusty roads; • Smoke from burning wood, vegetation, oil, waste materials, or gas; • Pollen grains, bacteria, fungal spores, dust from wheat, barley and other cereals, tiny pieces of skin from animals; • Dusts and fumes from chemical processes, welding, painting, gritblast cleaning and other industrial processes. • Fog, mist and “smog”, which are really tiny droplets of liquid and sometimes solid particles, forme
