The main causes of indoor air quality problems are pollution sources that release particles or gases into the air inside your home. Poor ventilation can raise indoor pollution levels by impeding fresh air circulation, which prevents dilution and transfer of indoor air pollutants outside the home. In places where heat and humidity are high, there tends to be higher concentrations of some pollutants.
Sources of indoor air pollution
Indoor air pollution can come from sources such as gas, oil, coal, kerosene, and wood burning products. Certain building materials can increase pollutant levels, such as asbestos, damp carpets, certain pressed wood products. Household cleaning, renovation and hobby products can be sources of indoor air pollution, as can central heating and cooling systems. Finally, outdoor sources such as pesticides, radon, and outdoor air pollution can contribute to indoor air pollution in your home.
Whether or not any of these things results in poor or dangerous indoor air quality depends on many factors. These factors include the age of the source, the quantity of pollutant it releases, how hazardous the pollutants are, and how well maintained the source is. For example, a gas stove emits carbon monoxide, but a properly adjusted stove emits far less than an improperly adjusted stove.
Effects on health
Poor indoor air quality can result in a variety of symptoms including nose and eye irritation, sore throat, dizziness, headache, and fatigue. These symptoms are treatable and, if the exposure to the pollutants is stopped, usually go away quickly. More serious illnesses, such as asthma pneumonitis, and humidifier fever are also possible consequences of poor indoor air quality. Your age and your general health status affect your sensitivity to indoor air pollutants, as does your genetic makeup, which varies from person to person. Sometimes the symptoms resemble those of a viral or bacterial infection, so it can be hard to know if the problem is due to indoor air pollution. It is important to note the time and place the symptoms started, and if they change depending on location. If the symptoms fade when away from home, for example, indoor air quality problems are a likely source of the problem. Some health effects take years of exposure to develop. They include cancer, heart disease, and respiratory diseases. Because these illnesses are so serious, it is a good idea to ensure good indoor air quality in your home at all times, even if no one living in your house has any symptoms. This is accomplished by eliminating sources of pollution or reducing their emissions, improving ventilation in the home, and by using effective air cleaners.
An Introduction to Indoor Air Quality (IAQ). http://www.epa.gov/iaq/ia-intro.html