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Indoor Air Quality

Indoor Air Quality

Research shows that most people spend about 90% of their time indoors. Because of this, indoor air has increasingly become a bigger health concern than outdoor air. Indoor Air Quality (IAQ) is a term used to describe how polluted the air inside a building is. The cleanliness or health effects of air in a building are affected by the amount of pollution from gases or particles released into the air. While there are many pollutants that can cause IAQ problems, a few of the most common are molds, environmental tobacco smoke (ETS), carbon monoxide (CO), pests and pesticides, radon and lead dust.


Molds are small organisms found almost everywhere, inside and outside, including on plants, foods and dry leaves. They can be any color – white, orange, green or black. Molds are beneficial to the environment, but they can affect your health and the structural integrity of your home when mold grows on indoor surfaces.

The key to controlling mold is to control moisture. There are many sources of moisture in a home, including flooding and sewage backups, leaky roofs, humidifiers, high indoor humidity and condensation, damp basements and crawl spaces, plumbing leaks and clothes dryers that are not properly vented.

To reduce humidity:

  • Use air conditioners and/or de-humidifiers when needed. Be sure to keep them clean and dry.
  • Use exhaust fans or open windows in kitchens and bathrooms when showering, cooking or using the dishwasher.
  • Vent clothes dryers outside.

To prevent condensation:

  • Reduce humidity (see above).
  • Increase ventilation or air movement by opening doors and/or windows, when practical. Fans can be used as needed.
  • Increase the air temperature.

The Cook County Department of Public Health (CCDPH) does not test for mold. Even if testing is done, no standards or guidelines exist to judge acceptable levels of mold. CCDPH does not recommend mold testing unless it will result in legal action. Monies spent for testing are best spent on the clean-up.

How to clean up mold:

A homeowner can perform clean-up; however, personal protective equipment, such as, rubber gloves, goggles, clothing to cover skin and an N-95 or HEPA respirator mask should be worn.

Clean-up should not be done by anyone who has a chronic illness, such as asthma or emphysema, allergies or immune disorders. If you have health concerns, consult a health professional before starting clean-up.

The source of moisture should be fixed before the mold is cleaned up. If not, the mold will grow again. How you clean up areas contaminated with mold depends on the surface where the mold is growing. A professional should be consulted if large areas (more than 30 square feet) are contaminated with mold. For hard surfaces, such as glass, plastic, varnished wood, tile, etc., you can take the following steps:

  • The surface first needs to be cleaned:
    • Use a non-ammonia soap or detergent in warm water and scrub the entire area affected by mold. Use a stiff brush or cleaning pad on block walls or uneven surfaces.
    • Rinse clean with water.
    • Dry completely.
  • The next step, if desired, is to disinfect the surfaces to help kill any mold missed by the first cleaning:
    • Ventilate the area before using a disinfectant. Open doors and/or windows or use fans, if necessary.
    • Disinfect the area with a solution of water and bleach (no more than 1 cup of bleach per 1 gallon of water). Never mix bleach with ammonia. The vapors are hazardous. Using bleach alone will not be more effective.
    • Let disinfecting areas air dry completely.

Considering discarding and replacing absorbent materials, such as ceiling tile, drywall and carpeting if they cannot becompletely dried within 48 hours.

How to clean up mold in schools and building:

In addition to the above, in buildings, mold can also be the result of a poorly maintained HVAC system. For information on mold remediation in commercial buildings, consult the U.S. Environmental Protection Agency’s “Mold Remediation in Schools and Commercial Buildings ???.

File a mold complaint:

In unincorporated suburban Cook County, contact CCDPH at (708) 974-7117 or use our complaint form . All other areas of Cook County should contact their local building department.


Carbon monoxide (CO) is an odorless, colorless and toxic gas. Because it is impossible to see, taste or smell the toxic fumes, CO can kill you before you are aware it is present. At lower levels, CO causes mild health effects that can be mistaken for the flu. These symptoms include headaches, dizziness, disorientation, nausea and fatigue. At higher levels, exposure to CO can result in death.

Sources of CO indoors are unvented kerosene and gas space heaters; leaking chimneys and furnaces; back-drafting from furnaces, gas water heaters, wood stoves and fireplaces; gas stoves; generators and other gasoline powered equipment; automobile exhaust from attached garages; and tobacco smoke.

To reduce exposure to CO:

  • Install CO monitors in your home. Check them regularly and make sure they are maintained properly. Effective January 1, 2007, every Illinois home is required to have at least one carbon monoxide alarm in an operating condition within 15 feet of every room used for sleeping.
  • Keep gas appliances properly adjusted.
  • Have a trained professional inspect, clean and tune-up central heating systems, such as furnaces, flues and chimneys, annually. Repair any leaks immediately.
  • Do not idle the car inside the garage.
  • Do not smoke, or allow anyone else, to smoke inside your home or car.
  • Do not use unvented space heaters, gas stoves, charcoal grills or Sterno-type fuels for heating the home.
  • Open flues when fireplaces are in use.
  • Put generators outside. Never use a generator inside homes, garages, crawl spaces, sheds or similar areas. Deadly CO levels can build quickly and linger for hours, even after the generator has shut off.
  • In the workplace, make sure there is adequate ventilation when working around CO sources, such as propane-powered forklifts and space heaters. Where exposure is unavoidable, workers should wear CO monitoring badges. Employers should regularly monitor the workplace.

If you suspect a CO problem, call 911 and leave the area immediately.


Household pests can be any unwanted or destructive insect or animal. This includes cockroaches, ants, rats and mice, to name a few. Droppings or body parts of pests can cause asthma attacks in persons with asthma. While pesticides may be needed in some situations, it is best to first try methods that do not involve the use of pesticides. To control pests:

  • Do not leave food (including dog or cat food) or garbage out.
  • Store food in airtight containers.
  • Clean all food crumbs or spilled liquids immediately.
  • Fix any leaks or moisture problems immediately.
  • Seal cracks or gaps and around windows and doors.
  • Try using poison baits, boric acid (for cockroaches), or traps.

If pesticides must be used:

  • Read the label! A pesticide product label is a legal document. You must follow the label directions.
  • Make sure there is plenty of fresh air when you spray and keep persons with asthma out of the area.
  • Limit the spray to the infested area.
  • Consult a Certified Pest Control Operator.

If someone is accidentally exposed to pesticides, contact the Illinois Poison Control Center at (800) 222-1222.


Radon is a cancer-causing, radioactive gas. According to the U.S. Environmental Protection Agency (EPA), radon is the number one cause of lung cancer in non-smokers and the second leading cause of lung cancer overall. Like carbon monoxide, you cannot see it, taste it, or smell it, but it can be a problem in your home.

Radon comes from the natural (radioactive) breakdown of uranium in soil, rock and water and gets into the air you breathe. Radon can be found all over the U.S. It can get into any type of building — homes, offices, and schools — and result in a high indoor radon level. But you and your family are most likely to get your greatest exposure at home, where you spend most of your time.

Radon from soil gas is the main cause of radon problems. Radon gets into the home by moving up through the ground to the air above and into your home through cracks and other holes in the foundation. Your home traps radon inside, where it can build up. Any home may have a radon problem. This means new and old homes, well-sealed and drafty homes, and homes with or without basements.

Testing is the only way to know if your home has a radon problem. The EPA and the Surgeon General recommend testing all homes below the third floor for radon. The EPA also recommends testing in schools.

To have your home or school tested for radon; contact a Licensed Radon Measurement Professional .


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