What are the sources of RSPM ?
Plastics, Synthetic fibers (including carpets, curtains, sofa covers), TV picture tubes, Computer Monitors and several other household items emit large quantities of positive ions. These have a tendency to attach themselves to the dust particles present in the air and give them a positive charge. The heavier particles are pulled to the ground by the gravitational force but the particles smaller than 4 microns experience an electrostatic force of repulsion which is greater than the gravitational force and manage to stay afloat permanently. This explains why RSPM counts inside houses and cars are often higher than those found on roads carrying heavy traffic. What is a HEPA Filter? HEPA is an acronym for High Efficiency Particulate Air. A HEPA Filter normally refers to a filter with an extremely small pore size of 1 micron or less. As the impure air is forced through this filter, all particulate matter larger than the pore size is unable to pass through and adheres to the filter membrane.