Chemical, biological and physical contamination of indoor air. It may result in adverse health effects. In developing countries, the main source of indoor air pollution is biomass smoke which contains suspended particulate matter (SPM), nitrogen dioxide (NO2), sulphur dioxide (SO2), carbon monoxide (CO), formaldehyde and polycyclic aromatic hydrocarbons (PAHs). In industrialized countries, in addition to NO2, CO, and formaldehyde, radon, asbestos, mercury, human-made mineral fibres, volatile organic compounds, allergens, tobacco smoke, bacteria and viruses are the main contributors to indoor air pollution. (source: United Nations Statistics Division)
Air pollutants that occur inside buildings or other enclosed spaces, Some examples of indoor air pollutants are nitrogen oxides, tobacco smoke, asbestos, formaldehyde, and carbon monoxide.
Indoor Air Pollution is the term used to describe the amount of contaminants in the air inside a building. Indoor air pollution can often be worse than outside air pollution due to poor ventilation. Unfortunately, it is often ignored. About 80 per cent of all indoor air pollution is human skin. The remaining 20 per cent is usually made up of dust mites, pet dander, smoke, pollen, sweat, and chemical compounds from various substances.