Air Filters: They Can Do More Harm Than Good

April 4, 2006 — -- Desperate affairs require desperate remedies. And no one is more desperate than allergy sufferers who endure the grip that allergies hold on their lives.

Remedies for allergies range from prescription medication to homeopathic treatments like grape seed extract, licorice root and massive doses of vitamin C. Few, if any, of these alternative treatments have proved effective, and medication often comes with unwelcome side effects.

Some people with allergies, however, swear by air cleaners. Manufacturers of these popular products claim that by removing or neutralizing animal dander, mold, pollen or other allergens, their air cleaner will help to eliminate the misery of allergies.

But health experts worry that this cure may not help everyone, especially if the unit uses ozone to clear the air. In some cases, according to Jeffrey Asher, vice president and technical director at Consumers Union, which publishes Consumer Reports, "The air cleaner turns on you."

"This is one of the products most people don't need to buy," Asher said of air cleaners. "The exception would be a person who has a problem with allergens."

Asher added that people who live with a smoker might also enjoy some relief by using an air cleaner.

"A good air cleaner will remove smoke from the air," he said.

Dr. Norman Edelman, chief medical officer for the American Lung Association, agreed that air cleaners may be effective in some cases.

"If you look at the engineering data, they are effective at removing particles from the air. There's some evidence that the good ones reduce the symptoms of allergies."

Most air cleaners operate with a filter, such as a mesh screen, a high-efficiency particulate air filter or an electrostatic system that collects particles that cling to surfaces within the cleaner.

But some air cleaners operate by generating ozone. Manufacturers of these products claim that the ozone works by attaching an oxygen molecule to other particles in the air, which then neutralizes or eliminates the particle's harmful or allergic properties.