Some Air Purifiers Create Smog-Like Conditions UPDATED MAY 12, 2006 AT 2:42 PM ET Correction: This article in its original form was inaccurate. The study involved two types of air purifiers, those commonly called ionic and those that employ a process called ozonolysis. Only those using ozonolysis were found to contribute to ozone levels that can in some cases exceed air quality standards. “Ionic air purifiers do emit ozone,” said lead researcher Sergey Nizkorodov, a chemistry professor the University of California, Irvine. But he added that “none of the ionic air purifiers produce enough ozone when they are used properly to exceed smog alerts.” The confusion was generated in part by a UC Irvine press release that did not clearly distinguish between these two types of machines. LiveScience regrets the error and any confusion it may have caused. The article has been revised. Here's how to create your own personal Stage 2 Smog Alert: Buy a personal air purifier that emits high levels of ozone.

These devices are marketed to reduce pollen and particulates in room air. One variety, though, can generate ozone levels in a room that exceed high-smog days in Los Angeles. Lead researcher Sergey Nizkorodov, a chemistry professor at the University of California at Irvine, noted that all “ionic” air purifiers emit some ozone. However, only purifiers based on ozonolysis appeared to result in the high ozone levels noted in his study. Unfortunately, not all manufacturers and retailers clearly distinguish between these two varieties of air purifiers. (LiveScience regrets any confusion resulting from an earlier version of this article that itself did not make this difference clear.) Air purifiers are popular in urban areas. They are touted as getting rid of dust, pollen and other airborne particles. Ionic air purifiers, one type of these devices, are said to work by charging airborne particles and then attracting them to metal electrodes. They emit small amounts of ozone as a byproduct of this ionization process.

The other machines, which employ ozonolysis, emit more ozone. In a small and poorly ventilated room, the ozone adds to existing ozone and creates potentially unhealthy concentrations. "People operating air purifiers indoors are more prone to being exposed to ozone levels in excess of public health standards," Nizkorodov said. The research, funded in part by the National Science Foundation, was announced today and is detailed in the Journal of the Air & Waste Management Association. Ozone high in the atmosphere protects Earth from damaging ultraviolet radiation. Down here, it is the main component in smog. Ozone can damage the lungs and cause shortness of breath and throat irritation, and it can also exacerbate asthma, scientists say. Nizkorodov and colleagues tested various air purifiers in homes, offices and cars. In many cases, according to a statement, ozone levels inside climbed above 90 parts per billion, exceeding California's basic safety threshold. In some cases, ozone soared higher than 350 parts per billion, which if measured outside would trigger a Stage 2 Smog Alert, an event that hasn't occurred in the Southern California coastal air basin since 1988.

California lawmakers are considering legislation to reduce emissions from indoor air purifiers. Meanwhile, both the state and the U.S. Environmental Protection Agency have issued advisories discouraging the use of the worst ozone emitters among these devices.oreck air purifier safety "These [ozonolysis] machines are insidious," said Barbara Riordan, acting chairperson of the California Air Resources Board (ARB), in a warning last year. air duct cleaning chesapeake"Marketed as a strong defense against indoor air pollution, they emit ozone, the same chemical that the ARB and … how to clean an oreck air purifier xlU.S. Environmental Protection Agency have been trying to eliminate from our air for decades. More chilling is that some people susceptible to the ill effects of ozone will eagerly bring these Trojan horses home."

Science does not even suggest that all air purifiers do what they're purported to do. An EPA fact sheet has this to say about air purifiers: "Available scientific evidence shows that at concentrations that do not exceed public health standards, ozone has little potential to remove indoor air contaminants. Some manufacturers or vendors suggest that ozone will render almost every chemical contaminant harmless by producing a chemical reaction whose only by-products are carbon dioxide, oxygen and water. Dandruff Found in the Air Beach Pollution Worse During Full Moon Springtime Means Sun, Flowers and Smog from Abroad Fresh Air In Your Car.This miraculous air purifier and ionizer eliminates bacteria, car exhaust, cigarette smoke, pollen, dust and other airborne contaminants. Removes unpleasant odors and fumes. Reduces musty and stale air. Relieves allergies, hayfever and asthma.The Air Purifier generates negative ions that neutralize positively charged contaminants... refreshing and cleaning the air!

The negative ions also keep you clear-headed and alert while driving. Car Air Purifier and Ionizer plugs directly into your car's 12V lighter socket.Car Air Purifier and IonizerWA9620$19.95Has anyone used an air purifier/ionizer, the personal kind worn around the neck for air travel? I'm wondering how beneficial it will be to reduce jet lag and/or sickness after being on a plane for a 7 hour trip. Also, any particular brands used that you can recommend? Unless it is attached to a perfectly sealing facemask it is useless. You also puck up germs by touching surfaces and then your mouth/nose/eyes. Just a gadget to separate you from your money.Lots of anecdotal evidence with people claiming they help, but these are the same people who swear that Skin So Soft is more effective for repelling mosquitoes than DEET. I have yet to see a peer reviewed scientific study that says they make any difference whatsoever. Okay, my response and working backward: 1. Skin So Soft does contain DEET but not a very high concentration, although its "natural" contents are supposed to make it effectiv.

I know of a former Canadian Scout group leader who swears by it for our northern climate. 2. Though a normal mask combined with a filter is not likely to reduce jet lag, a personal well-fitted and maintained mask could possibly reduce the risk of contracting an airborne virus on a plane. 3. Also, to see any benefit of reduced jet lag, any mask - with or without an attached filter - that has a supplemental oxygen source will suffice ... but the oxygen concentration going in the mouth must be above 40 percent. To get supplemental oxygen, a person would need either an O2 tank - highly unlikely in an airplane cabin - or an air/gas enhancer similar to a C-PAP machine. 1.) Who told you that Skin So Soft contains DEET? Not even their Skin So Soft Bug Guard Plus Expedition contains DEET. 2.) There is lots of anecdotal support for Skin So Soft as a mosquito repellent, unfortunately none of those claims have ever been back up scientifically. The New England Jounal of Medicine published one of the most respected and comprehensive tests to date, DEET worked for 300+ minutes and Skin So Soft lasted less than 10 minutes.

I'm glad it works for your Scout Leader pal though. The original poster asked if anyone had used one, the replies so far seem to indicate opinions rather than actual use. Groupon has a deal going on the Airtamer A302, for $39. I regularly get sick after any airplane trip so I ordered one. I am tired of my vacations being ruined by colds and worse. A trip to New Zealand resulted in losing two days flat on my back, same on a flight to Mexico. I will try anything to avoid this. Amazon has decent reviews on this device, for whatever that's worth. baraff, I can find no scientific studies that support the usefulness of these devices. That's not an opinion, that's a fact. The anecdotal evidence given in the reviews on Amazon, etc... In any case I totally understand your issues with air travel. I am blessed (thank God) with a strong immune system but I know lots of people who get knocked down after extended air travel and if one of these devices helps even a tiny little bit then that's fantastic.

Hope it helps you. Actually, personal air purifiers have been tested, by both Consumer Reports, the California Air Resources Board, and the Federal Drug Administration. "Personal" air cleaners: These are units designed to be worn around the neck, on a lapel, or in a pocket. To begin with, they are very dangerous because they emit ozone right at the breathing zone; therefore, they can trigger health problems in people with asthma and others with lung problems. They also are ineffective. When Consumer Reports tested one in a test chamber in January 2000, they said that it "barely reduced" the particle concentration in the surrounding air.1 In another study by the California Air Resources Board in 1999, they found that both personal air purifiers they studied exceeded the Federal Drug Administration recommended limit of ozone as well as the World Health Organization eight-hour air quality guideline of 60 ppb. They recommended that these devices not be used anywhere near the breathing zone, especially by children and persons with asthma, other respiratory diseases, or allergies.6

My apologies Laura, I should have been more precise. I stated I had never seen a test that supported their effectiveness. The tests that slammed them were done quite some time ago on units that are somewhat different than what is offered today. It would be nice to see a real test performed on present day units. I suspect the findings will be no different... You are correct Martian--there are no recent studies I can find. The last one was done in 2003, when Consumer Reports gave a Sharper Image product a "fail." Sharper Image sued Consumer Reports and lost. I wonder if, in the face of this, the ionizers have changed in terms of what they offer. Some technologies move faster than others.... I was having difficulty with long flights and did try a unit (Wein). Maybe coincidence, but I did feel better. Unfortunately, on my trip home I was told these are now prohibited by most airlines. (They actually confiscated mine and returned it on departure.) I checked and this is true - if they see you wearing one on most major US airlines, they will either tell you to remove it or confiscate it.