Viruses & Bacteria - Crowded conditions with poor air circulation can promote the spread of infectious diseases. Some bacteria & viruses thrive in buildings and circulate through indoor ventilation systems. For example, the bacterium causing Legionnaire's disease, a serious & sometimes lethal infection, and Pontiac Fever, a flu-like illness, have circulated in some large buildings.
Dust Mites - Ninety percent of the population that experience any allergy-based sensitivities react to the dust mite allergen. Once produced, the allergens settle into fabrics and carpet. The dust mite allergen remains potent for approximately 9 months. Individuals come into contact with the allergen after some activity like vacuuming, dusting, or making beds has “stirred-up” the area and caused the allergen to become airborne.
Molds produce tiny spores to reproduce, just as plants produce seeds. Mold spores waft through the air continually. When mold spores land on a damp spot indoors, they may begin growing and digesting whatever they are growing on in order to survive. When excessive moisture accumulates indoors, mold growth will often occur. Molds can trigger asthma episodes in individuals with an allergic reaction to mold.
Other Indoor pollutants: Combustion contaminants, carbon monoxide, carbon dioxide, nitrogen dioxide, sulfur dioxide.|
Organic compounds such as formaldehyde, fragrance products, pesticides, solvents, cleaning agents.
Airborne Heavy metals, lead and mercury vapor. Natural and Synthetic gasses like Radon.