Negative Ions

Allergies, seasonal affective disorder (SAD), tuberculosis, chronic depression, and asthma—what do these health problems have in common? Over the past 50 years researchers have been conducting experiments to alleviate or cure these maladies with the healing potential of negative ions.

While some results have been inconclusive, renewed interest in the ability of negative ions to simply and inexpensively kill airborne infections and surface bacteria has motivated new research efforts.

What are negative ions?

Also known as anions, negative ions are particles that contain at least one extra electron. This gives the particle a negative charge.

Outdoor sources

Natural environments, such as beaches, waterfalls, forests, and mountains, contain more negative ions than indoor environments. Ions are naturally created when moving water or air, sunlight, or radiation break apart air molecules. Negative ions gain one or more electrons to become negatively charged; positive ions lose one or more electrons to become positively charged.

People report feeling better after a spring thunderstorm when the air is charged with negative ions. In contrast, research in the 1980s found that winds that precede storms are charged with positive ions, such as Germany’s f?winds, which were believed to affect humans by increasing migraines, suicide, and crime.

Indoor sources

Negative ions can also be generated by air ionizers, sometimes known as negative ion generators. These devices use a high-voltage current to electrically charge (or ionize) air molecules.

Air ionizers are most commonly used in homes or in industrial and institutional settings such as hospitals. Since the SARS epidemic, some companies have created consumer products that contain negative ion generators, including toothbrushes, refrigerators, washing machines, and notebook computers.

Early research

Researchers have been conducting studies since the 1950s on the biological and sychological impact negative ions have on animals and humans.Researchers demonstrated that negative (and positive) ions accelerated Staphylococci cell death in clean air. Further research showed that both positive and negative ions were able to inhibit the growth of fungi and bacteria on solid surfaces, in water, and in air. Negative ions exhibited “a direct lethal effect” on bacteria, reported Science.

Recent research

During the last decade researchers have examined the effect of negative ions on mental health as well as their bacteria-killing potential.

Depression
Bright light and high-density negative air ions have been used to treat patients who suffer from seasonal affective disorder, or SAD. Researchers looked at whether bright light and negative ions would have a similar effect on chronic depression. They concluded that both treatments were effective at reducing the symptoms of chronic depression.

Recent research has demonstrated that negative ions had a positive mood-enhancing effect on subjects who were non-clinically depressed. High negative ion concentrations worked significantly better at improving mood than did low negative ion concentrations.
 
Seasonal affective disorder (SAD)
Building on the study above, researchers examined the use of negative air ionization and naturalistic dawn simulation to treat SAD. Treatments were administered during the last few hours of sleep. For a three-week period subjects received either dawn simulation, a dawn light pulse, post-awakening bright light, high-flow negative air ionization, or low-flow negative air ionization.

High-flow negative ionization and naturalistic dawn simulation acted as antidepressants and were viable alternatives to bright light therapy or medication. The low-flow negative ionization did not alleviate the symptoms of SAD.

One of the advantages of using high-flow negative ionization, according to researchers, is that they received no reports of ionizers disturbing their subjects’ partners’ sleep patterns the way dawn simulation can if partners awaken in the morning at different times.

Airborne infection
Researchers are re-examining the ability of air ionizers to control the spread of airborne infection, especially in hospitals and nursing homes.

A 10 1/2-month study of the effect of negative ionization in an intensive care unit demonstrated a decrease in Acinetobacter infections from 11 cases to only two.

Researchers have postulated over the years that negative ions possess a bactericidal property that enables them to destroy different types of bacteria. Just how they do this is unclear. Theories of what contributes to cell death include the electrical action of the ions, the action of their electric field, or the small amount of ozone that they produce.

Results showed the chief cause of cell death among the bacteria studied was exposure to ozone. However, the bacteria Mycobacterium parafortuitum experienced cell death due to exposure to the electric field. Despite these findings, researchers concluded that the bactericidal action of negative ions previously touted by earlier researchers was most likely exaggerated.

Tuberculosis transmission
A 2009 study examined the use of upper-room ultraviolet (UV) lighting and negative air ionization to prevent tuberculosis transmission in an HIV tuberculosis hospital ward in Lima, Peru. Exhaust air from the ward was passed through three guinea pig air-sampling enclosures that housed 150 guinea pigs for 535 days.

The UV lighting killed the tuberculosis while the negative ionization charged airborne particles so they adhered to surfaces. The end result was that upper-room UV lights reduced the transmission of tuberculosis by 70 percent; negative air ionization reduced the transmission rate by 60 percent.

This low-cost, effective method of controlling tuberculosis infection warrants further study, according to the researchers.

Hospital equipment decontamination
A recent study reported in BMC Infectious Diseases (2010), examined the ability of negative ionization to prevent the transmission of the Acinetobacter infection on plastic
medical equipment.

Air ionizers negatively charged the air as well as medical equipment such as ventilator tubes. By altering the electrostatic environment, Acinetobacter particles in the air were repelled from some plastic surfaces and attracted to others. This could potentially be a simple, cost-effective way to prevent the contamination of medical equipment.

As research into the bactericidal properties of negative ions continues, you can breathe in the benefits of negative ions any time you enjoy the great outdoors.