What is the relationship between indoor and outdoor air pollution and how do they differ?
Indoor air quality is important to human health because we spend nearly 90 % of our time indoors. Occupants of indoor environments may be exposed to a variety of pollutants originating from human activities; combustion from heating and cooking, consumer products, furnishings, building materials and outdoor air. The quality of indoor air depends both on the quality of outdoor air and on the strength of emissions of indoor sources. In most inhabited spaces there is a continuous exchange of air with the outside. Therefore, all contaminants of outdoor air are likely to be present indoors except ozone which reacts with the surfaces of objects within a house and is thus greatly reduced in concentration.
