Indoor Pollution: How Healthy Is Your Home?

Ahhh, home at last. Time to unwind, kick off your shoes, and take a deep breath of . . . pollution?

Yep. Indoor pollution. You may be surprised to know that indoor air -- in homes and other buildings -- can be more polluted than outdoor air, even in big cities and industrialized areas. And the average home contains hundreds of sources of potentially harmful pollutants, from cleaning supplies to carpets.

So how concerned should you be?

It depends on your particular situation and how you conduct yourself around the known problem substances. By and large, there's probably no need to be frightened of the air in your own home if you take a few commonsense steps when problematic substances are involved.

Which Ones May Pose Problems?

Some indoor pollutants are more dangerous than others. But the health risks associated with indoor air pollution are related to the levels you're exposed to and the amount of time you're exposed to them, so limiting those aspects of your exposure is key.

We're all exposed to pollutants, indoor and outdoor, every day. But we've evolved to tolerate low levels of exposure, though some people may be more sensitive than others.

For the most part, you can rest assured -- evidence suggests you'd have to breathe in unusually high levels of household pollutants for an extended period of time to suffer serious, long-term health effects. And in an average home, that's unlikely to happen.

But for people who are sensitive to chemicals and allergens, even low levels in the home can trigger irritating and uncomfortable reactions. And some pollutants, like carbon monoxide, can be lethal.

So don't let your home wreak havoc with your health. Put your pollution radar to the test with this RealAge quiz, and find out how you can minimize your exposure to common household pollutants.


This pungent pollutant can be found in most homes, but can you identify its source? Is it:

  • A. Cosmetics

  • B. Glues and adhesives

  • C. Pressed-wood furniture, shelving, or paneling
D. Insulation materials

  • E. All of the above

The correct answer is: E. All of the above.

This strong-smelling, colorless chemical is used widely in the production of everything from building materials to nail polish.

In homes, the biggest source of formaldehyde tends to be pressed-wood products, such as plywood, particleboard, and medium-density fiberboard (MDF). Used to make shelving, cabinets, furniture, and paneling, pressed-wood products release formaldehyde fumes into the air.

The amount of formaldehyde released from these products gradually decreases over time, which means new pressed-wood products emit more formaldehyde than older items.

Even so, the amount of formaldehyde that these products may emit is regulated by the U.S. government, and there is little evidence to suggest that household exposure level causes any long-term negative health effects -- although studies show that levels of formaldehyde vary significantly from home to home.

Most research showing negative health consequences from exposure to formaldehyde involved industrial exposure levels. Studies show that people who work with formaldehyde, and therefore are exposed to high levels for prolonged periods, may have a slightly increased risk of developing certain types of cancer. But the impact of typical home-level formaldehyde on cancer risk is considered to be negligibly low.

The bottom line: If you or a member of your family is sensitive to the stuff, keep the possible health effects in mind when you're making decisions about new furniture or home improvement projects. Using products that contain formaldehyde can temporarily increase levels in the air and may cause short-term symptoms in people sensitive to the fumes.

Other household items that may emit formaldehyde gas include:

  • Wallpaper
  • Permanent-press fabrics, such as drapes and linens
  • Glues and adhesives
  • Nail polish
  • Foam insulation

Formaldehyde is just one of many chemicals classified as volatile organic compounds (VOCs). Some are harmless, some are hazardous. Learn about other unwanted VOCs in your home by answering the question below.

Volatile Organic Compounds (VOCs)

Which of the following household products is likely to contain VOCs?

  • A. Air fresheners

  • B. Tap water

  • C. Dry-cleaned clothing

  • D. None of the above

  • E. All of the above

The correct answer is: E. All of the above.

Read on to find out more about VOCs in your home.

Volatile organic compounds (VOCs) are present in thousands of products. And although they pollute both indoor and outdoor air, VOC levels are typically much higher indoors.

Like formaldehyde, VOC levels vary from home to home and from room to room within a house. Factors linked to elevated levels of VOCs include indoor painting within the previous 12 months, new carpet, indoor smoking, and new furniture.

Studies conducted by the U.S. Environmental Protection Agency (EPA) indicate that people may be exposed to elevated levels of VOCs while they're using products that contain them. Hundreds of items found in the average home may contain VOCs. Check out the table below for a list of common sources of VOCs in the home.

Household Sources of VOCs

These products are likely to contain benzene, methylene chloride, or trichloroethelyne.

Paint, paint strippers, and glues
These products are likely to contain benzene, methylene chloride, or trichloroethelyne.

Dry-cleaned clothing or fabrics
Perchloroethylene (Perc) is used in dry cleaning. It evaporates slowly at room temperature and may linger on recently dry-cleaned items.

Air fresheners, cleaning supplies, mothballs, and moth repellants
Dichlorobenzene is the main ingredient in mothballs and some bathroom deodorizers. It also may be found in some cleaning supplies.

Water: tap water, swimming pools, and hot tubs
Most municipal water supplies, as well as swimming pools and hot tubs, are treated with chlorine as a disinfectant. When chlorine reacts with naturally occurring organic matter in the water, it can create chloroform as a by-product.

So What Might They Do to You? 

Immediate health effects of exposure to high levels of VOCs may include ear, nose, and throat irritation; headaches; dizziness; nausea; fatigue; loss of coordination; and allergic skin reactions. And results from a study of young children suggest that exposure to elevated levels of VOCs in the home may be linked to an increased risk of childhood asthma.

In high doses, some VOCs have been linked to an increased risk of cancer. But typical home levels are well below those associated with this risk. Still, avoiding concentrated exposure to sources of VOCs in the home is a commonsense move that can prevent both short-term reactions and long-term health consequences.

Find out more about carcinogens, and how they are classified, from the American Cancer Society.

Unlike pungent VOC pollutants, some other indoor air pollutants are entirely odorless. Answer the next question to learn more about what you can't smell.


Radon is the second leading cause of lung cancer in America; the cancer risks from radon exposure are particularly relevant for people who smoke. But do you know where radon comes from?Is it from:

  • A. Radiators

  • B. Fluorescent lighting

  • C. Soil and groundwater
D. Wood-burning stoves or fireplaces

  • E. All of the above

The correct answer is: C. Soil and groundwater.

Radon is a radioactive gas that occurs naturally in soil and rock. It is also found in well water and some building materials made from earth or stone. Building materials, however, are unlikely to cause dangerous levels of radon in your home. It's radon from soil that causes most cases of elevated residential radon.

Radon gas moves up from the soil underneath the house and wafts its way inside through cracks in the foundation, gaps in floorboards, and openings around pipes. Once it's in your home, radon gets trapped and can build up to dangerous levels. It's estimated that elevated levels of radon are present in 1 of every 15 homes in America.

Radon testing is fairly inexpensive. If someone in your household smokes, or if you are concerned about radon levels for other reasons, you can have the air tested quickly and easily.

Had enough of gases and chemicals? Answer this final question to find out how to reduce pollution from living things.

Biological Baddies

Biological pollutants, such as dust mites, pollen, and animal dander, can trigger allergic reactions and symptoms similar to hay fever. Do you know where these irritants are most likely to be lurking in your home?

  • A. Carpets and rugs

  • B. Fluffy toys

  • C. Beds and bedding

  • D. Air-conditioning systems
E. All of the above

The correct answer is: E. All of the above.

Biological pollutants are present to some degree in every home. They include dust, dust mites, mold spores, bacteria, animal dander, insects, and pollen.

The main sources of these pollutants are pets; damp or moist areas; bathrooms; air conditioners, humidifiers, and dehumidifiers; mattresses, blankets, pillows, and sheets; carpets and rugs; upholstered furniture and soft furnishings.
Fortunately, these allergens don't affect everyone, but if you or someone in your family suffers from allergies, you'll want to take active steps to reduce levels of these allergens in your home.

Think you might be allergic? If this list of symptoms sounds familiar, see your healthcare provider for allergy testing:

  • Sneezing
  • Wheezing
  • Coughing
  • Difficulty breathing
  • Eye, nose, and throat irritation
  • Headaches
  • Fatigue
  • Dizziness

So now that you have a realistic picture of what to worry about and what not to worry about when it comes to indoor air quality, is there anything you can do to help keep the air in your home clean? Certainly -- read on.

Five Steps to a Healthier Home

1. When there is a good alternative, avoid buying products that contain high levels of formaldehyde or other VOCs. For example, try solid wood or stainless steel if someone in your home is sensitive to formaldehyde. When possible, choose cleansers that have low VOC levels. Also, store materials with high VOC levels -- such as paints and solvents -- in the garage instead of the house. And keep cleaners, paints, and solvents tightly sealed when not in use.

2. Keep your home well ventilated, especially when putting up wallpaper; doing any varnishing or painting; using cleansers or solvents; bringing new pressed-wood furniture into your home; hanging freshly dry-cleaned drapes; or even when painting your nails.

Open doors and windows to let fresh air in and help disperse fumes. And keep the indoor temperature moderate to minimize formaldehyde emissions.

To the extent that the water in your area is chlorinated, it may contain low levels of chlorination by-products such as chloroform. Low levels are not considered to be harmful, but if your water has a strong chlorine smell, you may want to open a window or turn on the exhaust fan when taking a hot shower or bath.

3. Test your home for radon. You can test for radon yourself or hire a qualified radon tester to do it for you.
Radon test kits are available at most hardware stores. The National Safety Council (NSC) also sells short-term and long-term test kits that meet all EPA requirements. 

If you'd prefer to have a professional test your home, the EPA can help you find a qualified radon tester in your area. 
If your home has elevated levels of radon, take action. There are several fix-it options available to reduce the amount of radon in your house. 

4. Dust and vacuum your home frequently. If someone in your home has active allergies. Dust mites thrive in beds, bedding, and upholstered furniture, so make sure you vacuum those as well as the floor. Keep in mind, however, that cleaning can momentarily increase the allergens in the air. If you have severe allergies or asthma, have someone else do the dusting and vacuuming, throw open all the windows, and wait a couple of hours before returning to the house.
You may want to consider investing in a HEPA-filter vacuum. HEPA vacuums improve air quality and reduce both allergens and allergic reactions.

5. Don't let moisture or humidity build up anywhere. Mold and dust mites flourish in warm, moist environments, and heat and humidity can increase formaldehyde emissions.

Use exhaust fans in the bathroom and kitchen to help keep humidity levels low. If you use an air conditioner, humidifier, or dehumidifier, make sure it's well maintained and cleaned regularly.

And if you find mold in your home, clean it up immediately. Mold needs water to grow, so try to identify the source of the moisture. If a leak, pooling water, or excess condensation is feeding the mold, fix the problem to prevent the mold from returning.

A Breath of Fresh Air

You look after your body by eating a healthful diet, exercising, and getting preventive screenings. Don't overlook the spaces in which you live, work, and play when patrolling your health. Although it's unrealistic -- and unnecessary -- to try to rid your home of pollutants entirely, keeping the levels of potentially harmful gases, chemicals, and allergens in your home to a minimum may improve your day-to-day health and well-being.

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