Scientists also discovered that ozone produced by air purifiers adds to ozone already present in any room -- a prediction that had never been experimentally verified in a realistic indoor environment.
"These results mean that people operating air purifiers indoors are more prone to being exposed to ozone levels in excess of public health standards," said Sergey A. Nizkorodov, a chemistry professor in the School of Physical Sciences at UCI.
Nizkorodov and UCI chemistry students Nicole Britigan and Ahmad Alshawa published their research in the current issue of the Journal of the Air & Waste Management Association. Their findings will be studied by officials deciding how to regulate the distribution of indoor air purifiers.
California lawmakers are considering legislation that would require the California Air Resources Board to adopt regulations to reduce emissions from indoor air cleaners by 2008. The state board and the U.S. Environmental Protection Agency have issued advisories discouraging use of air purifiers, but the devices remain on the market because no agency has the outright authority to regulate how much ozone they produce.
Indoor air purification has gained widespread popularity with the surge in air pollution problems in urban areas.
Air purifiers target dust, pollen, airborne particles and volatile organic compounds, which are emitted by a wide range of products, including paint, cleaning supplies and pesticides. These pollutants are believed to aggravate respiratory and other health problems.
Indoor air purifiers are advertised as safe household products for health-conscious people -- especially those who suffer from allergies and asthma -- but some purifiers produce ozon
Contact: Jennifer Fitzenberger
University of California - Irvine