Negative ion therapy can help relieve symptoms of seasonal affective disorder (SAD) and other mood disorders.
Ionization is the process by which atoms and molecules become electrically charged, forming ions. An atom can gain one or more electrons to form a negative ion or lose electrons to form a positive ion. Air ionization refers to the ionization of air molecules. This may occur as a result of various natural processes, or a device may be employed to ionize the air for health benefits, either directly or by purifying the air by removing allergens, pathogens, and airborne pollutants. It is generally accepted that negative ions are more effective than positive ions for these purposes.
Ionization is the process by which atoms and molecules become electrically charged, forming ions.
Air ionizers generally work by applying a high voltage electrical current to a metal pin or needle. An electric current consists of a flow of negatively charged electrons. As the electrons approach the needle tip, the electrostatic repulsion between them causes them to detach from the metal surface and attach to the nitrogen and oxygen molecules in the air and to airborne particles, forming negative ions.
Most ionizers cannot remove many common allergens, including pet dander.
While the claimed direct health benefits of negative ions, such as relief from seasonal affective disorder (SAD) and depression, are the subject of research and debate, there is good evidence from a number of studies that ionization, particularly with negative ions, can purify the air by removing small suspended particles that can harbor harmful bacteria or allergens. It appears that when these particles ionize, they tend to settle on grounded surfaces such as walls and floors, leaving the air cleaner. Air ionization has been successfully used in the dusty atmosphere of poultry farms, for example, to remove harmful bacteria from the air and reduce the incidence of disease.
Air ionization can help lessen the severity of asthma.
Another useful application for air ionizers is in preventing electrostatic discharge. For example, an electrical charge can build up on sensitive electronic parts during handling or assembly, resulting in sparks that cause damage. An air ionizer can help neutralize charges before discharge occurs.
The effects of air ionizers are not always beneficial. The ionization of nitrogen and oxygen can result in the formation of small amounts of ozone and nitrogen oxides. These are lung irritants and are classified as pollutants. There is concern that some air ionizers may generate harmful levels of these gases.
Ionizers can remove particles from the air that cause sinus problems.
Air ionization can also occur naturally, such as during thunderstorms and by the action of sunlight. Rocks subjected to pressure can generate electrical currents that can manifest as ionization of the air around surface rocks. It was suggested that earthquakes could be predicted by detecting ionization effects in seismic zones.