Ionic air purifiers' dirty little secret: They don't get rid of dust

The product: Dust, cigarette smoke, pollen and pet dander: With so many irritants floating around our homes and work places, clean air is a hot commodity. Americans spend hundreds of millions of dollars on furnace filters and air cleaners each year. Though some consumers are simply trying to bring a little extra freshness into their lives, many others hope that their investment will help relieve their asthma or allergies.

By Chris Woolston

April 21, 2008