August, 2004
Inspection News and Views from the American Society of Home Inspectors

IAQ: Indoor Air Quality


Educate yourself. Educate your clients.

The major sources of indoor air pollution include:
  • Radon
  • Environmental Tobacco Smoke (ETS)
  • Biologicals
  • Carbon Monoxide (CO)
  • Nitrogen Dioxide
  • Organic Gases
  • Respirable Particles
  • Formaldehyde
  • Pesticides
  • Asbestos
  • Lead

The relative importance of any single source depends on how much of a given pollutant it emits and how hazardous those emissions are. In some cases, factors such as how old the source is and whether it is properly maintained are significant. For example, an improperly adjusted gas stove can emit significantly more carbon monoxide than one that is properly adjusted.

The Environmental Protection Agency publishes a booklet that outlines the sources, health effects, levels in homes and steps to reduce exposure for each of the major causes of indoor air pollution.”The Inside Story: A Guide to Indoor Air Quality” is  online at

To order a single copy of the booklet:
EPA’s IAQ Information Clearinghouse (IAQINFO)
800-438-4318; 703-356-4020
P.O. Box 37133 Washington, DC, 20013-7133

To order a bundle of 25 for $44:
Call The Government Printing Office at
202-783-3238 or send check or money order
for $44.00 to: Superintendent of Documents, P.O. Box 371954,
Pittsburgh, PA, 15250-7954. Include the stock number 055-000-00441-2.