The Portable Ionic Air Purifier we breathe is made up of positive and negative ions; the positive ions attach to airborne molecules such as dust, germs, mold, and pollen and cause them to clump together so that we breathe them in large amounts. Negative ions occur naturally in clean, fresh environments, such as near lakes and out in the countryside. Air purifiers take in air filled with positive ions, filter out pollutants and emit clear air rich with the negative ions that are better for you.