Indoor Air Quality – the average American spends 20 hours or more of each day in various indoor environments such as work, school, and home. Because the air they breathe recirculates, it accumulates pollutants. Indoor air may contain two to five times as much pollution as outdoor air. Health experts believe this contributes to the rise over recent decades in ASTHMA and other respiratory diseases. Indoor air pollutants may be visible, linger as odors, or remain undetected. The risk to health does not necessarily correlate with the ability to detect the pollutant; some of the most hazardous substances (such as carbon monoxide) have no smell or visible presence.
|COMMON INDOOR AIR POLLUTANTS|
|aerosol products||animal dander|
|asbestos in older structures||BACTERIA|
|body fragrances||CARBON DIOXIDE|
|carbon monoxide||cleaning solutions|
|formaldehyde||glues, paints, and solvents|
|molds, mildew, and fungi||ozone|
|viruses||volatile organic compounds|
Ventilation and outdoor air exchange are important for bringing fresh air into the building or home and releasing indoor pollutants so they can disperse. This helps reduce exposure to harmful substances and lower the risk of resulting health conditions. Federal regulations establish ventilation and air exchange rates for commercial buildings. Indoor air also may be too dry or too moist (humid), requiring humidification or dehumidification to make it more comfortable to breathe. Humid air supports the growth of molds and fungi, which can cause hypersensitivity response, ALLERGIC RHINITIS, chronic BRONCHITIS, and other upper respiratory tract conditions. Improperly cleaned humidifiers also can become pathogenic reservoirs, harboring and dispersing colonies of molds and bacteria. Central home heating systems have filters that homeowners or residents must periodically change.
The US Environmental Protection Agency (EPA) administers regulations and standards for indoor air quality, and recommends a three-prong approach:
- Control pollutants at their sources: This may include no smoking indoors and installing carpets that do not contain VOCs,
- Ventilate: Open windows and circulating fans move air containing pollutants outside and bring in fresh air.
- Clean the air: Air cleaners and filters use various methods to extract specific kinds of pollutants from the air. The EPA cautions that air cleaners cannot substitute for proper ventilation and source control as the primary maintenance measures for clean air. Some air cleaners may add different pollutants to the air, such as particulates or ozone.
See also BUILDING-RELATED ILLNESS; ENVIRONMENTAL CIGARETTE SMOKE; LEGIONNAIRES’ DISEASE; RADON EXPOSURE; SICK BUILDING SYNDROME.