Indoor Air Quality

Protect the Integrity of Air Quality in Your Home for Safety

Maintaining the integrity of air in your home is critical to the health and safety of your family. Your home is where you live for one-third of your life or more. The air you breathe and substances you encounter there play an immense role in long-term health. Here is a list of dangerous intruders that sometimes confront unsuspecting homeowners. These are risks that need to be actively monitored and managed.


Radon is a radioactive gas that is emitted from soils that can move into your home through gaps in the foundation. Any home may contain radon. Radon can come from many sources, including well water or building materials, but most commonly it comes from soil.

If you would like to test your home for radon, or would like more information, contact your State Radon Contact and click on your state to get contact information. Or, you can contact one or both of the two privately-run National Radon Proficiency Programs (listed below alphabetically) that offer proficiency listing, accreditation and certification in radon testing and mitigation.

The National Environmental Health Association (NEHA)
National Radon Proficiency Program
Toll Free: (800) 269-4174 or (828) 890-4117
Fax: (828) 890-4161
The National Radon Safety Board (NRSB)
Toll Free: (866) 329-3474
Fax: (914) 345-1169
E-mail Address:

Radon is estimated to cause some 21,000 lung cancer deaths each year in the United States. There has been no evidence of other effects of radon exposure. International scientific communities are united in the belief that radon causes lung cancer. Radon in schools is often remedied by increasing ventilation, but this does not necessarily solve the problem completely.

There are several ways to lower radon exposure in your home. Some methods prevent radon from entering, and others decrease the levels once the radon is inside.

Dangerous Biological Pollutants in Your Home

While outdoor pollution continues to be a source of concern and a matter for public attention, indoor pollution can be a significant problem as well. Everyday activities such as cooking, heating, cooling, cleaning, and redecorating can cause the release and spread of indoor pollutants. Many Americans spend up to 90 percent of their time indoors, often at home.

Indoor pollutants may include animal dander, dust mites, cockroach parts, infectious bacteria or viruses, or pollen. It is impossible to be rid of them completely, but they can be reduced.

Allergic reactions may be the greatest sign of indoor pollution, and can range in symptoms from watery eyes, runny nose, sneezing, congestion, itching, and coughing, to wheezing, headaches, fatigue, and difficulty breathing. Those with asthma are at the highest risk. If you fall into this category, you may want to speak with your physician.

The following questions may help you assess whether biological pollution could be affecting your health:

  • Do you or your family members have frequent headaches, fevers, itchy and watery eyes, a stuffy nose, dry throat, or a cough or, do you complain of feeling tired or dizzy all the time, wheeze or have difficulties breathing on a regular basis?
  • Did these symptoms appear after you moved?
  • Do the symptoms disappear when you are away from your home?
  • Have you recently remodeled your home?
  • Did your symptoms occur during or after these activities?
  • Does your home feel humid? Can you see moisture on the windows or on other surfaces, such as walls and ceilings?
  • What is the usual temperature in your home? Is it very hot or cold?
  • Have you recently had water damage, or is your basement wet or damp?
  • Is there any obvious mold or mildew?
  • Does any part of your home have a musty or moldy odor?
  • Is the air stale?
  • Do you have pets?
  • Do your house plants show signs of mold?
  • Do you have air conditioners or humidifiers that have not been properly cleaned?
  • Does your home have cockroaches or rodents?

Infectious diseases may pass through indoor ventilation systems and then spread indoors.

Experts suggest that you explore your home using your senses. Fix leaks, cover dirt crawlspaces, use exhaust fans in bathrooms and kitchens, use dehumidifiers, raise temperatures of cold surfaces, check carpet on concrete for moisture, address regional climate-specific issues, clean air conditioners and dehumidifiers, wash bedding, clean appliances, clean refrigerator drip pans, clean moist surfaces, replace moldy things, dust and vacuum often, have professionals check your heating and cooling systems, look for stains or anything rotting, do not mix chemicals indoors, avoid breathing cleaning vapors, and discard water-damaged items.

The following article reviews common dangerous substances found in homes.

The 10 Most Dangerous Toxins in Your Household

By Claude Morgan

“Toxins in U.S. homes now account for 90 percent of all reported poisonings each year,” says Rose Ann Soloway, administrator of the American Association of Poison Control Centers. That’s an epidemic of hazardous living by any standard. And while these figures include everything from non-fatal aspirin overdoses to the deadly consumption of drain cleaners, they fail to include long-term exposure to toxins like lead and asbestos.

To address the climbing domestic injury rates associated with household toxins, Congress and the Centers for Disease Control (CDC) in 1992 created the Unintentional Injury Center to focus on the health dangers of consumer goods and modern home living. Other federal agencies are following suit. The Environmental Protection Agency (EPA) now has branches which deal with home indoor air quality, lead exposure and ubiquitous low-level toxicity, and the Department of Housing and Urban Development publishes a pollution look-out list for first-time homebuyers.

The short list of toxins under your roof may surprise you:

Formaldehyde off-gasses (evaporates) from cushions, particleboard and adhesives used to manufacture most inexpensive wood-based products. Carpets and carpet cushions may also off-gas formaldehyde, causing eye and upper respiratory irritation. According to the EPA, formaldehyde may even cause cancer;

Radon is the second-leading cause of lung cancer in the U.S., warns the Surgeon General. Radon is a natural radioactive gas which can seep into homes through cracks in the basement, the surrounding foundation, and in well water. It enters the body quietly through the airway;

Lead keeps epidemiologists returning to the drawing board, says Soloway, “mostly because we know more now about the adverse effects of low-level exposure.” Levels once thought to be acceptable are now known contributors to learning disabilities and behavioral problems. Lead is found in paint in older houses, old plumbing, and soil near highways and busy roads. It causes neurological and kidney damage, high blood pressure, disrupted blood cell production, and reproductive problems;

Carbon monoxide will kill an estimated 660 Americans this year. Don’t look for exhaust fumes in the attached garage; the biggest culprit is the unserviced furnace burning propane, natural gas, butane or oil

Arsenic is still laced in many household pesticides and is increasingly used as a wood preservative. Low levels of inorganic arsenic “may increase lung cancer risk,” according to the CDC. The Department of Health and Human Services agrees, adding arsenic compounds to the list of known carcinogens;

Vinyl chloride is the source of “new car smell”: The plastic interior of a new car off-gasses this known carcinogen. Water sitting in PVC pipes overnight may be steeping into a toxic tea. Very large exposures can lead to “vinyl chloride disease,” which causes severe liver damage and ballooning of the fingertips;

Hydrofluoric acid “can cause intense pain and damage to tissues and bone if the recommended gloves happen to have holes in them,” says Soloway. This highly corrosive substance is the active ingredient in many household rust removers;

But even the most liberal list of known toxins pales next to the order of volatile organic compounds (VOCs). VOCs comprise hundreds of natural and man-made, carbon-based agents. They react quickly with other carbon-based compounds, and evaporate easily, making them ideal solvents. VOCs can be found in disinfectants and pesticides too.

Solvents: Benzene and methyl ethyl ketone traverse cell walls unchecked by normal cell defenses. Both are known carcinogens. Cousins toluene, xylene, 1,1,1-trichloroethane (TCA) and trichloroethylene (TCE) make up the lion’s share of the solvent market;

Disinfectants: Phenols, which include biphenyl, phenolics and the preservative pentachloraphenol, are found in disinfectants, antiseptics, perfumes, mouthwashes, glues and air fresheners;

Pesticides: Chlordane, aldrin, dieldrin, though all banned for nearly two decades, continue to show up airborne in older houses.

Don’t be a statistical figure on the CDC’s tracking list: Be aware of what substances, from pesticides to cleaners, pose real threats in your household. Maintain ingredient awareness. Many poisonings still occur because of product combinations, like the ammonia-chlorine bleach reaction, which produces the deadly respiratory irritant chloramine (a problem labeling practices have not addressed). Replace toxic agents with non-toxic alternatives. Above all, educate your household to reduce risk and exposure.

For practical ideas on reducing risk, consult the following books: Living Healthy in a Toxic World by David Steinman and R. Michael Wisner (Berkley, 1996); Toxins A-Z: A Guide to Everyday Pollution Hazards by John Harte, Cheryl Holdren, Richard Schneider, and Christine Shirley (University of California, 1991); Home Safe Home: Protecting Yourself and Your Family from Everyday Toxics and Harmful Household Products by Debra L. Dadd (Putnam, 1997).

For more information, contact the Unintentional Injury Center, (770)488-4652.

Copyright 1997, The Los Angeles Times Syndicate, All Rights Reserved

A Guide to Indoor Air Quality

According to research, those living in industrialized nations spend more than 90% of their lives indoors, making indoor air pollution a great concern. Infants, elderly, and those with chronic diseases are at even greater risk than the general population.

Lungs are most vulnerable to pollutants, and manifest the greatest number of symptoms of pollution exposure, but diagnosis can be difficult as the symptoms can mimic colds, flu, and other allergies. Below are some topics to research for anyone interested in more information about indoor air quality.

  • Diagnostic Quick Reference
  • Diagnostic Checklist
  • Environmental Tobacco Smoke (ETS)
  • Other Combustion Products
  • Carbon Monoxide (CO)
  • Nitrogen dioxide and Sulfur dioxide
  • Animal Dander, Molds, Dust Mites, Other Biologicals
  • Tuberculosis
  • Legionnaires Disease
  • Allergic Reactions
  • Hypersensitivity Pneumonitis
  • Humidifier Fever
  • Mycotoxins
  • Volatile Organic Compounds (VOCs)
  • Formaldehyde
  • Pesticides
  • Heavy Metals: Airborne Lead and Mercury Vapors
  • Airborne Lead
  • Mercury Vapor
  • Sick Building Syndrome (SBS)
  • Asbestos
  • Radon

Methods to Control Indoor Air Pollution

There are three basic methods of controlling indoor air pollution: addressing the source, enhancing ventilation, and cleaning the air. Source control is the most effective means, but air ventilation is very common also. Air cleaning is not viewed as an effective solution by itself.

New technologies in home construction increasingly incorporate systems that use outdoor air, including heat exchangers.

The air purifiers on the market vary widely and are equipped to deal with gaseous pollutants. Sufficient equipment must collect the pollutants well and provide adequate circulation. There has been public discussion about houseplants helping with indoor pollution, but this has not been verified in research. The EPA does not recommend using air cleaners to address radon and its decay products.

For most indoor air quality problems in the home, source control is the most effective solution. This section is a source-by-source review of the most common indoor air pollutants, their potential health effects, and ways to reduce levels in the home. (For a summary of the points made in this section, see the section entitled “Reference Guide to Major Indoor Air Pollutants in the Home“).