What do you know about ionizers and ozone? I want to buy a bedroom air purifier for my allergies and I'm confused by what the different brands claim. One says that ozone is good and ions are bad, and the next one says the exact opposite. I can't find the straight story without somebody trying to sell me something.
Trusting a salesperson to give you the facts is sometimes like taking investment tips from the Internet. By the time you begin to suspect you've been misled, the checks are cashed, the company has turned to vapor, and what seemed to be an oil strike in South America turns out to be an abandoned gas station in South Dakota.
For people with all ranges of allergies, a room air purifier can be a necessity. Lots of us suffer misery from airborne pollen a few days each season, but for some, animal dander, mold spores or dust mite excretions (aka: poop) cause year-round wretchedness. Removing these specks from the air has been a challenge since their discovery. The most basic system of pulling air through a filter has been pushed aside by newer methods involving ions, ozone, ultraviolet light and even heat.
In nature, rainstorms, waterfalls and atmospheric radiation produce negative ions. Ionizers duplicate the effect through a process called coronal discharge, scattering charged particles in a radius of about 50 feet around an emitter. These floating negative ions magnetically attach to positively-charged dust and other odds and ends hovering in the vicinity. By clumping together, indoor pollutants become heavier and either fall to the ground, or stick to walls, draperies or passersby. Over time, surfaces near the unit can appear soiled if not frequently wiped or vacuumed (passersby, at least, are self-cleaning). Some new models, called electrostatic precipitators, have positively-charged, easily-cleaned plates to attract the little dust clusters, thus eliminating a potential dirt-zone surrounding the unit.
There has been a lot of interest in ion generation for air purification since some early studies showed that coronal discharge destroys both the dust mite and cat dander allergens. Research done in U.K. hospitals has shown that ionizing the air in intensive care units can significantly cut down the infection rate in recovering patients by removing bacteria from the air. In addition, Japanese investigators found that the presence of those negative ions in the air had a relaxing effect on surgical patients. Indeed, these circulating ions have been found to be useful in unlikely ways: for treatment of Seasonal Affective Disorder (SAD), as stress reduction in computer users, and in two Swedish daycare centers, ionized air reduced children's absenteeism by half.
However, the news is not all rosey. A recent study found ionizers had no effect on chronic asthma, which seemingly should respond to the removal of airborne irritants. Another hurdle to overcome is that many ionizers create small quantities of ozonewhich, despite claims to the contrary, is bad.
Drummed out of the cancer cure corps due to non-performance, ozone has risen again like an air-cleaning phoenix. Expensive purifying units create this highly reactive form of oxygen by drawing air across a high-voltage surface. As oxygen molecules pass through the electrical field, some are ionized and become ozone. This unstable molecule theoretically destroys allergens, organisms and odor in the air through some magical process known only to Penn and Teller, leaving behind just carbon dioxide, oxygen and water. According to dozens of scientists and the Environmental Protection Agency, this claim is not only misleading and wrong, it's also dangerous.
Ozone is a lung irritant. Even small amounts can irritate the throat, cause coughing and worsen respiratory conditions. True, large quantities of ozone are used for rough decontamination following fires or floods, but these areas are always unoccupied. In addition, the chemical byproducts that the process leaves behind may be equally unsafe. No studies demonstrate that safe amounts of ozone are of any use in controlling indoor air pollutants. Since ozone's natural purpose in the upper atmosphere is as protection from harmful rays, it should, like most politicians, stay out of the bedroom and be kept far, far away.
A mechanical purifier with a high efficiency particulate air (HEPA) filter might be a louder, but more efficient, choice for your allergies; these are required to trap more than 99 percent of smidgens larger than a virus. Additionally, the white noise made by such a filter might be a good thing, since it will drown out the sound of the guy coughing in the next apartment. My guess is he sells ozone purifiers.