A friend of mine is selling these “corona discharge” air filters–she has severe asthma and swears this little gizmo is better than pooping gold bricks. Is this truly the miracle we asthma sufferers are looking for? This unit claims to be a “miniature miracle” made possible by “a revolutionary discovery in electrodynamic negative corona discharge purification technology.” Supposedly it’s “more advanced than any filter/fan air purifier or HEPA filtration device” and cleans air “naturally….Similar to a thunderstorm, a corona discharge of negative high energy is passed through the pollutants.” In layman’s terms it’s supposed to zap any particle large enough to be an allergen that passes through it. Or at least that’s how it was marketed to me. How about it, Cecil? Is it the answer to my prednisone prayers or a crock of shit?
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Maybe it’s just me, but when I hear somebody go on about revolutionary discoveries, negative high energy, or anything to do with ions (which are what a corona discharge device produces), I make sure I’ve got a firm grip on my wallet. Still, one never likes to dismiss things out of hand. We even tested laundry balls, remember? So I sent Jane to rummage through the archives. The assembled research presents the usual inconclusive muddle. Some observations:
Air ionizers may improve some things, but they don’t improve asthma. I’m not saying ionizers are useless. Studies found that they reduced transmission of airborne disease in poultry, cut down on microbial pollution in a dentist’s office, etc. But they didn’t help asthma and arguably made things worse (Warner et al, 1993).
