1. Atmosphere E

2. Indoor Air Quality  Indoor air quality refers to the properties of indoor air that affect the health and well- being of those in it.  There have been as many as 900 contaminants identified as present in indoor air at ppb or higher.

3. Types of contaminates  VOCs are volatile organic compounds such as formaldehyde (H 2 CO), benzene (C 6 H 6 ), toluene (C 7 H 8 ), chloroform (CHCl 3 ), acetone (C 2 H 6 O) and styrene (C 8 H 8 ). These come from cleaning products, plastics, perfumes, hair sprays, paints, carpet, furnishings, dry-cleaned clothes, plywood and other products.

4. Biological Contaminants  Molds, fungi, bacteria, viruses, pollen, and insects. In order to lessen biological contaminants, indoor humidity should not exceed 50%.

5. Combustion Products  Carbon monoxide, nitrogen dioxide, sulfur dioxide, tobacco smoke components, and polyaromatic hydrocarbons such as benzo [a] pyrene.

6.  Contaminants generated by office equipment and supplies such as ozone from computer terminals and photocopiers, ethanol and methanol from duplicating machines, and acetone from typewriter correction fluid.

7.  Environmental tobacco smoke (ETS)  It is estimated that 470,000 tons of tobacco are burned indoors each year generating both mainstream and sidestream smoke.

8.  The concentration of pollutants include:  1. air exchange rate  2. the rate at which pollutants are generated indoors.  3. reaction rates among indoor air components.

9. RADON  Radon is a radioactive, colorless, odorless and tasteless gas formed by the nuclear decay of U-238 in ground under and around buildings.  When inhaled it can cause lung cancer.  It is measured in picocuries per liter.  A picocurie is equal to about 4 nuclear disintegrations per minute or about 16 nuclear disintegrations per minute in a liter of air.

10. FORMALDEHYDE  Formaldehyde, H 2 CO is a pungent-smelling gas found both indoors and outdoors.  It comes from carpets, cabinets, cigarettes, and insulation.  Phenol-formaldehyde and urea- formaldehyde resins are found in plywood and foam insulation (UFFI).  UFFI was banned in 1982 but a court action reinstated its use in 1983.  Formaldehyde irritates tissue and is a possible carcinogenic (cancer causing) chemical.