Capitalizing on the need for clean, fresh air, enterprising salesmen have begun promoting negative ion generators or ionizers. By continually releasing negative ions in the air, these devices will not only rid the air of dust, smoke and bacteria but are said to prevent headaches, asthma and other respiratory problems. Before we answer that question, allow me to give you a little history lesson. Air Molecules Ions were discovered in 1899 by German physicists Julius Elster and Hans Friedrich Geitel. These air molecules are either positive or negative depending on the number of protons and electrons they carry.
Positive ions have more protons while negative ones have more electrons.
Air normally contains a mixture of negative and positive ions. These electrically charged molecules are produced by nature from background radiation, cosmic rays, electromagnetic waves, the sun, lightning and waterfalls. These factors determine the amount of negative and positive ions in the atmosphere. Ions are formed most commonly in the soil, where trace elements of radioactive potassium, radon, and uranium initiate the ion reaction. An atom of oxygen hit by a radioactive ray immediately links up with four to six molecules of water vapor to form an ion.