“Ions” are charged particles. They are floating in the air around us all of the time and have either negative or positive charges. Ions that are negatively charged are called “negative ions” or “anions”. Ions that are positively charged are called “positive ions” or “cations”. The beneficial effect of negative ions is first known to human since more than one hundred years ago. However, actual implementation of negative ions in clinical medicine is only about 10 years, and the use of negative ions in daily healthcare products becomes popular only in the recent years.
Of all the gaseous molecules that make up the air, oxygen and carbon dioxide molecules have more power in gaining the electrons. In addition to that, oxygen occupies larger proportion in the air, resulting in formation of oxygen anions as the free electrons are captured by oxygen molecules. As such, the so called “negative ions” actually means cluster of negatively charged oxygen molecules. This cluster of molecules usually comprised of not more than 12 gaseous molecules surrounding the charged oxygen molecule. Water molecule is also one of the most easily ionized molecules. In environment with abundant water molecules such as waterfall, negative ion exists as negatively charged water molecules (with hydroxyl ion attached to water molecules).
Ions in the air can be divided into three categories : small, medium and large ions. Only the small ions are biological active as they are small enough and able to penetrate and enter human body to result in health effect.
How Is Negative Ions Produced?
Ions can be generated when a large amount of energy is applied to an atom or a molecule. Negative ions are created in nature with air molecules broken apart by UV radiation from sunlight, cosmic radiation, radioactive substances, thunderstorm, waterfall and sea waves. Plants that carry out photosynthesis are also able to generate negative ions. Under this natural phenomenon, negative ions are created and diminished continuously, maintaining at a dynamic balance state.
Our earth surface is possessing negative charge under the effect of the ionosphere layer of the atmosphere, resulting in repelling of negative ions out of earth surface and attraction of positive ions towards earth surface. As such, under normal condition, earth surface has higher concentration of positive ions than negative ions, with a positive to negative ions ratio of more than 1, and the ion counts are usually about 400-700/cm3. When the concentration of positive ions are much more than negative ions, that is when our health are affected. The known best environment for health is waterfall where negative ions concentration exceeding positive ions with a ratio of about 2 to 1.