What Level of Filtration Do I Need?
Indoor air pollution consists of many different irritants and allergens. These include amany airborne allergens and lung damaging pollutants such as house and textile dust, pollen, smoke, cat and dog dander, dust mites and their feces, automobile exhaust, soot particles from laser printers and copiers, bacteria, fungus and mold spores. Blueair air purifiers reduce odors, too. These pollutants are implicated in a wide range of illnesses from irritating to severely debilitating and even fatal!
Airborne pollutants are measured in microns. To give you some idea, one micron is 1/25,000th of an inch. A sharp pencil dot is about 50 microns in diameter and human hairs are between 30 and 120 microns.
There are essentially three size ranges of indoor pollutant particles. Large particles are greater than .9 microns in size. We generally notice these particles as dust that settles on furnishings. Particles of this size are a less serious health hazard in that the cilia (or hairs) that line our noses and sinuses catch these particles before they enter our lungs.
The category of particle size that presents the greatest health concern is the middle range. These consist of pollutants that are .3 to .9 microns in size. These are small enough to get past the cilia in our sinuses and too small to be easily exhaled. These lung-damaging particles become lodged in lung tissue and are implicated in a wide range of respiratory and other often serious illnesses.
There are also very small particles, which are smaller than .3 microns in size. Many of these particles are so small that they can be inhaled and then exhaled without harm. However, these very small particles can also become lodged in lung tissue and create serious health problems as well.
Therefore, it is very important that an air purifier be able to filter particles .3 microns and smaller in size. The Blueair 501 filters to 99.9% efficiency at .3 microns and 99.97% efficiency at .1 micron!
