EPA studies show that the air inside most modern homes is usually at least ten times more polluted than the air outside. How can this be? There are many reasons, some of which were discovered only recently. They include invisible assassins like radon and CO2, as well as gas-emitting chemicals like formaldehyde used in making modern carpeting, drapery, household cleaners, furniture, and building materials. There are also common airborne pollutants such as pollen, viruses, dust, dust mites and damp areas where standing water can breed mold, mildew and other microbes.
Much of this problem is attributed to the way modern homes are built—for purposes of energy efficiency, and to be as air-tight as possible. However, making the structure results in the trapping of foul air, chemicals, irritants – even minuscule insects are often trapped in modern homes, where the air circulates over and over. This can lead to eye irritation, sinus congestion, sneezing, runny noses, stuffiness, colds, flu, headaches, dizziness, outbreaks of allergies and asthma, sore throats, and various other respiratory ailments.