Ozone Emissions
Some types of air purifiers -- specifically ozone generators, electrostatic precipitators and ionizers -- emit ozone into homes. Ozone is a colorless, toxic and unstable gas that has three oxygen atoms in each one of its molecules. The gas occurs naturally in the upper atmosphere, but it is also a common component of man-made smog. Ozone generating air purifiers deliberately emit ozone gas as a strategy for eliminating bacteria and chemicals in the air. In contrast, some electrostatic precipitators and ionizers emit ozone unintentionally as a byproduct of their function. These latter types of purifiers electrically charge contaminants in the air to remove them. The charging process can result in ozone release. The California Environmental Protection Agency states that ozone exposure is harmful to cells in the lungs and airways. Side effects of exposure to the gas can include shortness of breath, coughing and chest tightness. Patients with asthma or other preexisting health conditions may experience intensified symptoms of those conditions as a result of ozone exposure.
Read more : http://www.ehow.com/list_7596430_disadvantages-air-purifiers.html