Dust

Dust is solid particles caused by natural forces or mechanisms such as processing, destruction, softening, packing a fast, blasting and other organic and inorganic materials. Dust is one ingredient that is often referred to as particles floating in the air (Suspended Particulate Matter / SPM) with a size of 1 micron to 500 microns.
In the case of air pollution both inside and building space dust is often used as one indicator of pollution that is used to indicate the level of danger both to the environment or to health and safety. Dust particles will be in the air in a relatively long time in a state of kite flying in the air then enters into the human body through breathing. In addition to harm to health may also interfere with eye gaze penetrating power and can hold a variety of chemical reactions so that the composition of dust particles in the air becomes very complicated because it is a mixture of various materials with a relative size and shape is different.
From the nature of the dust is categorized in:

1. The nature of the deposition, ie dust which tends always to settle because of gravity of the earth.
2. Wet surface properties, its nature is always wet coated by a very thin layer of water.
3. Clotting properties, because the nature is always wet the dust with one another tend to stick to form a clot. Moisture levels above the saturation point and the presence turbelensi dust in the air easier to form clots.
4. Static electricity dust, the dust has properties of static electricity that can attract other particles in the opposite thus dust particles in solution accelerates clotting.
5. Opsis properties, particle wet / humid others can emit visible light in a dark room.