Studies by the US EPA show indoor air pollution to be one of the top five environmental problems in public health today. According to some studies, levels of pollutants indoors can be 2-100 times higher than outdoors. Since most people spend up to 90% of their time indoors, indoor air quality is an important part of public health.

Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in homes. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the home. High temperature and humidity levels can also increase concentrations of some pollutants.

Pollutant sources can include combustion sources (i.e. gas, kerosene, coal, wood or tobacco products), mold and moisture, household cleaning products, and radon, amongst many others. The relevance of these pollutants depends on the amount of the pollutant emitted into the indoor environment.

Some pollutant sources continuously release pollutants (i.e. air fresheners, building materials, etc.). Other sources, related to daily activity, release pollutants intermittently in the home. Intermittent sources include smoking, the use of unvented or malfunctioning stoves, furnaces, or space heaters, and the use of cleaning products and pesticides in housekeeping. For more information about a smoke free home, please go to ODH's tobacco use prevention page.






Check out the IAQ pages on the menu bar on top of this page for information on specific IAQ pollutants. The following links will help provide you with some general information and resources to determine the source and solution for your indoor air problems.

US EPA Indoor Air Quality
Information from the US Environmental Protection Agency on various indoor air quality topics, including sources and solutions.
ODH Health Homes
Information from the Ohio Department of Health about their Indoor Environment Program.
OSHA Indoor Air Quality
Information from the US Department of Labor's Occupational Safety and Health Administration about indoor air quality in the Occupational Safety and Health Administration about indoor air quality in the workplace.
Air Cleaners and Your Health
Ohio Indoor Air Quality Coalition fact sheet on choosing the right air cleaners for your home.
Mold is a living organism that occurs naturally in our environment.  It grows in damp or wet environments and eats the matter on which it grows.  Outdoors, mold is an integral part in the natural breakdown of dead organic matter like fallen leaves and dead trees.  Indoors, however, mold can become a serious health threat.   Molds use microscopic spores which float through the air to reproduce.  If there is a high enough concentration of mold in an indoor environment, it may cause allergic reactions, asthma attacks, infections, or other respiratory problems.  Continuous exposure to high levels of mold may lead to allergies or increased individual sensitivity.

Mold will not grow unless water is present.  If you have mold growing in your home, there is a moisture problem that must be addressed.  The sooner the source of moisture (i.e. leaky plumbing) is removed, the less mold will need to be cleaned up.  If you have a water problem, it is best to correct the problem within 24-48 hours to help prevent mold from growing and spreading.

Ohio Department of Health Indoor Environments Section - Provides advice and information on indoor air hazards. Phone: 800-200-2526.
Radon detection kits are inexpensive and easy to use. You can purchase a kit at your local hardware store or other retail outlets. After you've completed testing your home, mail the entire kit to the manufacturer for analysis.  Short-term or long-term testing kits are available. To order a Free Radon Test Kit and have it shipped to your home, visit:

Radon is a gaseous radioactive element that is naturally occurring in our environment. It is an extremely toxic, colorless gas that can be condensed to a transparent liquid and to an opaque, glowing solid. It is derived from the radioactive decay of radium and is used in cancer treatment, as a tracer in leak detection, and in radiography.  Radon is completely invisible to sight, smell, or taste.  Radon is a known carcinogen and exposure to high levels over a period of time can lead to lung cancer.  It is considered the second leading cause of lung cancer in the United States.  Potential sources of radon in your home include earth and rock beneath the home, well water, and building materials.

The risk of developing lung cancer from exposure to radon is dependent on the average annual level of radon in your home and how much time you spend there. The longer your exposure to radon, the greater the risk. Risk is even greater for smokers.  Based on a national residential radon survey completed in 1991, the average indoor radon level is 1.3 picocuries per liter (pCi/L) in the United States. The average outdoor level is about 0.4 pCi/L.

For more information, contact the Ohio Department of Health at their toll free number, 1-800-523-4439 or
Lead is a naturally occurring metal that has long been considered a harmful pollutant in the environment.  The US EPA lists lead-based paint, contaminated soil, dust and drinking water as the most common sources of lead.

Lead affects many systems within the human body, including the central nervous system, kidneys, and red blood cells.  Higher levels of lead in the body can lead to convulsions, coma, or even death.  In 1991, the Secretary of the Department of Health and Human Services named lead "the number one threat to the health of children in the United States."  Children are more vulnerable because the lead is more easily absorbed into growing bodies.  The tissues of children are more sensitive to the damaging effects of lead to the body.

There are two primary sources of lead in the home: lead based paint and lead-contaminated dust.  Many older homes in the United States contain lead based paint.  If you are renovating an older home with lead-based paint, consult a professional on proper removal before you begin any work.  Mini blinds manufactured in Mexico and Asia also contain lead.  Over time, the mini blinds break down due to exposure from sunlight.  As the blinds break down, a layer of lead-contaminated dust forms on the blinds.  This lead-contaminated dust can be hazardous to a child if accidentally ingested directly or indirectly.
Volatile organic compounds are emitted as gases from both solid and liquid products in the home.  VOCs contain chemicals that can have both short-term and long term effects on your health.  There are literally thousands of products available that emit VOCs to the environment.  The concentration of VOCs inside the home can be up to ten times higher than outdoors.  Some common products known to emit VOCs are paints, paint strippers, pesticides, cleaning supplies, aerosol sprays, air fresheners, copiers, printers, correction fluid, glues, adhesives, permanent markers, and dry cleaned clothing.

Potential health effects from VOCs include eye, nose, and throat irritation; headaches; nausea; loss of coordination; and liver, kidney and central nervous system damage.  As is the case with most pollutants, the degree of health effects varies based on the concentration of exposure levels and the amount of time exposed.

More information is available on the US EPA for Indoor Air.
Asbestos is a mineral fiber that was widely used in the 20th century for various building materials as a fire retardant.  The widest use of asbestos in buildings was 1940-1975.  Asbestos can typically be found in homes in old insulation, fire-proofing, acoustical material, or floor tiles.  When asbestos containing materials are disturbed or deteriorate, microscopic asbestos fibers are released into the air.While there are no immediate health effects from exposure to asbestos, there is a higher risk of chest and abdominal cancers, as well as lung disease.  Asbestos fibers small enough to be inhaled can accumulate in the lungs and lead to lung cancer, mesothelioma, and asbestosis.  Most people that experience asbestos-related illness have had occupational exposure to elevated levels of asbestos.

While current regulations ban or restrict the use of asbestos in new buildings, many older buildings still contain asbestos.  If you have asbestos in your home, it is best to leave it alone if it will not be disturbed.  Material in good condition will not release asbestos fibers if they are not disturbed.  If the asbestos in your home must be removed, it must be done by a qualified professional contractor that is certified for asbestos removal.