Particulates are fine particles in the air (airborne particulates). They come from the car exhaust, are invisible to the naked eye and not to be confused with black smoke. They contain a mixture of unburnt and partially burnt fuel as well as lubricating oil and compounds which are regarded as carcinogenic (or cancer forming).
In general, the smaller and lighter a particulate is, the longer it will stay in the air. The size of the particle often determines too where in the body the particle may come to rest and possibly cause health effects. Smaller particles, such as silica, tobacco smoke, lead, some materials used in office equipment, and combustion by-products get past the nose and upper airways and are deposited in the Iungs.
The particles of most concern are referred to as PM10.These are particulates of less than 10 micrometres which remain suspended in the air and can be inhaled into the lungs.
