Air purifiers remove mold from the air. Mold is a serious problem for many buildings. Mold has been called "the next asbestos." Homes with serious mold problems may become unlivable. In serious cases it costs tens of thousands of dollars to remove.
Air purifiers also remove other bacteria from the air. If you have serious allergy problems I recommend trying out an air purifier before you drug yourself up. You may be pleasantly surprised what a difference air quality makes for your allergies once all of the air pollution is removed.
There are many pollutants in your home air besides natural ones that cause allergies. With so many chemicals and other synthetic products in the air it is important that the air you are breathing every day is clean. This is especially true when many homes receive little ventilation. During the winter the windows are shut tight and the heater is on; during the summer a window might be cracked open but probably not when the air conditioning is on.
