What Causes Indoor Air Problems? Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in buildings. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the structure. High temperature and humidity levels can also increase concentrations of some pollutants. Why is Indoor Air Quality Important? Indoor air quality is a major concern to businesses, building managers, tenants, and employees because it can impact the health, comfort, well being, and productivity of building occupants. Most Americans spend up to 90% of their time indoors and many spend most of their working hours in an office environment. Studies conducted by the U.S. Environmental Protection Agency (EPA) and others show that indoor environments sometimes can have levels of pollutants that are actually higher than levels found outside. Pollutants in our indoor environment can increase the risk of illness. Several studies by EPA, states, and independent scientific panels have consistently ranked indoor air pollution as an important environmental health problem. While most buildings do not have severe indoor air quality problems, even well-run buildings can sometimes experience episodes of poor indoor air quality. A 1989 EPA Report to Congress concluded that improved indoor air quality can result in higher productivity and fewer lost work days. EPA estimates that poor indoor air may cost the nation tens of billions of dollars each year in lost productivity and medical care. Indoor Air Pollution and Health Health effects from indoor air pollutants may be experienced soon after exposure or, possibly, years later. Indoor air quality (IAQ) problems are not limited to homes. In fact, many office buildings have significant air pollution sources. Some of these buildings may be inadequately ventilated. For example, mechanical ventilation systems may not be designed or operated to provide adequate amounts of outdoor air. Finally, people generally have less control over the indoor environment in their offices than they do in their homes. As a result, there has been an increase in the incidence of reported health problems. Immediate effects Immediate effects may show up after a single exposure or repeated exposures. These include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Such immediate effects are usually short-term and treatable. Sometimes the treatment is simply eliminating the person's exposure to the source of the pollution, if it can be identified. Symptoms of some diseases, including asthma, hypersensitivity pneumonitis, and humidifier fever, may also show up soon after exposure to some indoor air pollutants. Long-term effects Other health effects may show up either years after exposure has occurred or only after long or repeated periods of exposure. These effects, which include some respiratory diseases, heart disease, and cancer, can be severely debilitating or fatal. It is prudent to try to improve the indoor air quality in your home or office even if symptoms are not noticeable. Sick Building Syndrome The term "sick building syndrome" (SBS) is used to describe situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. The complaints may be localized in a particular room or zone, or may be widespread throughout the building. In contrast, the term "building related illness" (BRI) is used when symptoms of diagnosable illness are identified and can be attributed directly to airborne building contaminants. A 1984 World Health Organization Committee report suggested that up to 30 percent of new and remodeled buildings worldwide may be the subject of excessive complaints related to indoor air quality (IAQ). Often this condition is temporary, but some buildings have long- term problems. Frequently, problems result when a building is operated or maintained in a manner that is inconsistent with its original design or prescribed operating procedures. Sometimes indoor air problems are a result of poor building design or occupant activities. Indicators of SBS include: •        Building occupants complain of symptoms associated with acute discomfort, e.g., headache; eye, nose, or throat irritation; dry cough; dry or itchy skin; dizziness and nausea; difficulty in concentrating; fatigue; and sensitivity to odors. •        The cause of the symptoms is not known. •        Most of the complainants report relief soon after leaving the building. Indicators of BRI include: •        Building occupants complain of symptoms such as cough; chest tightness; fever, chills; and muscle aches •        The symptoms can be clinically defined and have clearly identifiable causes. •        Complainants may require prolonged recovery times after leaving the building