Ions can be attached molecules or atoms that contain an electrical charge and exist in nature in various sizes. Small ions only last between 30 and 300 seconds before losing their charge, but are extremely active.
Small ion densities range from 900 to 1,100 negative ions and 1,000 to 1,200 positive ions per cubic centimeter (ions/cm3) in pristine natural environments. At sea level ion density is typically around 500 negative and 600 positive ions/cm3. In cities and inside buildings ion levels drop by 80% to 95% and can be barely detectable in small spaces.
As ion density decreases, so does the air quality. By increasing the quantity of both positively and negatively charged small oxygen ions, air quality is improved. This is the basis of needlepoint bipolar ionization technology.