“If the choice is made to use an air cleaner, the reviewed evidence suggests choosing one that ensures high efficiency over an extended period of time (at least several months) and does not produce ozone levels above 0.05 ppm, either intentionally or as a by-product of its design. If air cleaners are to be used, they should either contain charged or uncharged fibrous media, or they should conform to FDA regulations for medical devices.” American Lung Association

The third strategy, air cleaning, relies on devices that are either incorporated into the mechanical ventilation system or moved from room to room as portable units with an inherent blower to further reduce the concentration of airborne pollutants. Although air cleaners in general are not appropriate single solutions to indoor air quality problems, they can be useful as an adjunct to effective source control and adequate ventilation. Air cleaning alone cannot adequately remove pollutants from all sources typically found in residential environments. For example, some allergens settle out of the air fairly rapidly and are not always amenable to air cleaning. Nor does ventilation effectively remove such particles. Therefore, source control should always be the first choice for air pollution control in residences.

However, air cleaning is recognized as one of the three strategies to improve indoor air quality and has become increasingly popular as specific populations of individuals attempt to improve the air quality in their residences and immediate environs to relieve symptoms associated with various diseases such as asthma, rhinitis, sinusitis, and allergic respiratory disease.  

With the prevalence of asthma increasing in the last decade, particularly in children, to an estimated 14.6 million Americans affected and the mortality rate due to asthma almost doubling, we must carefully consider the value of simultaneously applied source control, ventilation, and air cleaning in relieving symptoms and improving health.