Indoor Air Pollutants

An indoor air pollutant is a substance that is present inside buildings that has a harmful health effect on the occupants of the building. Since most people spend more time indoors than outdoors, exposure to indoor air pollutants is an important environmental hazard.

Indoor air pollutants have become a serious problem in recent years due to efforts by builders to make homes and other buildings more energy efficient.  Modern buildings are built to restrict the flow of air from the inside out and vice versa. These new building practices work well to save energy. However, reduced airflow in a building can cause air quality problems in three ways.

• New buildings contain new types of insulation that are developed to help us use less air conditioning during the summer and less heating during the winter.  This new insulation can add to indoor air pollution because of chemicals, like formaldehyde, used to make the newer types of insulation.
• Reduced amounts of outside air entering a building can cause the levels of air pollutants to build up over time and become greater than outdoor levels of air pollution.
• Large air conditioning and heating units have lots of air duct space for molds and bacteria to grow in.
  

There are many types of indoor air pollutants.  Go to the next page to find out about different types of indoor air pollution.