Understanding Indoor Air Pollution

The air we breathe often falls short of expectations. Coal plants release harmful CO2, large trucks emit toxic exhaust, and cows contribute methane to the atmosphere. Sometimes, just seeing the pollution outside can make you want to stay inside.

However, what's inside your home may be even more concerning. Indoor air pollution, caused by the accumulation of harmful chemicals and materials, can be up to 10 times worse than outdoor air pollution [source: Dunn]. Enclosed spaces allow pollutants to accumulate more easily than in open environments. Imagine dumping a gallon of oil into the ocean compared to dumping it into a bathtub. In the ocean, it disperses and dilutes in the vast waters, but in the bathtub, it remains concentrated. This is how pollutants behave in small, enclosed spaces like your home or office.

You might assume indoor air pollution doesn’t affect you, especially if you don’t live near highways, farms, or factories. You don’t smoke and avoid using wood-burning stoves. But pollutants can come from unexpected sources, such as your home, its surroundings, and common household products. Given that people spend about 90 percent of their time indoors, with around 65 percent of that in their homes, it’s clear why indoor air quality is a significant concern [source: Dunn].

Some of the side effects of indoor air pollution may seem mild, similar to a common cold, but long-term exposure can lead to severe consequences like coma, lung cancer, and even death. Interested yet? Read on to learn more about the causes of indoor air pollution.

What Causes Indoor Air Pollution?

Formaldehyde, PCB, asbestos: These are substances you definitely don’t want to associate with your living environment. Yet, chances are, you come into contact with at least one of these chemicals daily. If not, you're still not completely safe. Indoor air pollutants can be released in intense bursts, such as when using spray paint, or in smaller quantities over time, like chemicals seeping from your carpet.

Both formaldehyde and polychlorinated biphenyls (PCBs) are found in many everyday household products. Although PCB production was banned in the U.S. in 1970, it still lingers in items like wire coatings, sealants, paints, and wood floor finishes. Asbestos, another notorious indoor pollutant, has been largely banned as well but remains in older homes, insulation materials, textured paints, and floor tiles.

Formaldehyde is commonly used in the manufacturing of building materials and household products. It is predominantly found in pressed wood products used in subflooring, shelving, cabinets, and furniture, but also appears in permanent-press fabrics, adhesives, and paints.

Let’s explore some of the other causes of indoor air pollution and where they originate from:

The harm caused by these pollutants varies depending on individual sensitivity. The elderly, children, and those with weakened immune systems are particularly vulnerable. Ventilation plays an important role in limiting the damage caused by these pollutants. If fresh air is allowed to circulate regularly, pollutants won’t have the chance to build up and reach harmful levels. Returning to the bathtub analogy, ventilation is like slowly draining the polluted bathtub water and replacing it with clean water: Over time, the oil becomes less of an issue. But if the plug is left in place and nothing is done, you’ll be left with a grimy bathtub ring. Unfortunately, many modern, energy-efficient buildings are almost completely airtight—like a bathtub with the plug firmly in place.

Discover how living in a poorly ventilated, polluted indoor environment can affect your health on the next page.

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Sick Building Syndrome and Other Health Consequences

Many individuals who were displaced by Hurricane Katrina in 2005 managed to survive the storm only to face another devastating blow. After relocating to government-provided trailers, they began suffering from various health issues, ranging from headaches and congestion to trouble breathing. Tests soon revealed that the trailers contained formaldehyde levels as much as 50 times higher than the U.S. Environmental Protection Agency's designated "elevated" level of 5 parts per million [source: Brunker]. It turned out that the carcinogen was leaching out of the composite wood and plywood panels in the trailers. Despite years of assurances that the trailers were safe, the U.S. Federal Emergency Management Agency eventually ordered the residents to vacate in early 2008.

Though less widely publicized, similar incidents of indoor air pollution are happening every day. The effects can be immediate and short-lived, or they may be severe, showing up years after repeated exposure. Common symptoms include sore throat, headaches, persistent coughing, and itchy, watery eyes and nose. In more severe cases, long-term exposure can lead to chronic respiratory issues, heart disease, and even cancer.

One of the most noticeable indoor pollutants is environmental tobacco smoke, or secondhand smoke, which contains 200 known toxins and at least 43 compounds that can cause cancer. Even if you're not a smoker, you may still be affected by secondhand smoke if you live or work with someone who is. This "passive smoking" contributes to approximately 3,000 lung cancer deaths and between 35,000 to 50,000 heart disease deaths annually in non-smokers. It also causes between 150,000 and 300,000 respiratory infections in infants each year and worsens the condition of up to 1 million people suffering from asthma [source: American Lung Association, EPA].

There are many other invisible yet equally dangerous indoor air pollutants. For instance, consider the following:

You can explore more about these pollutants in the Mytour articles A Guide to Home Safety and How to Allergy-Proof Your Home. Discover ways to reduce indoor air pollution on the next page.

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Solutions to Indoor Air Pollution

If you think your living space may be polluted, don’t panic. There are simple solutions you can try. If you're unsure whether your home is affected, ask yourself these questions:

Answering “yes” to these questions doesn’t guarantee that your home has indoor air pollution, but it’s a strong indication. A good test is to try some of the solutions for indoor air pollution listed on this page and see if you notice an improvement.

As you might imagine, one of the simplest and most effective ways to reduce indoor air pollution is to tackle the source directly. For some sources, like those that contain asbestos, simply sealing them can help prevent exposure, while for others, like pesticides, complete elimination might be necessary.

Some sources of pollution, such as a gas stove or a fuel-burning space heater, may be harder to remove. However, you can reduce the risks by using these devices according to the manufacturer’s instructions and ensuring proper ventilation at all times.

As you discovered earlier, ventilation plays a key role in reducing indoor pollutants. Since most heating and cooling systems recirculate air instead of bringing in fresh air, it’s a good idea to open windows and doors when possible, use window or attic fans, and run exhaust fans in the bathroom and kitchen. This is especially important when using products with potentially harmful chemicals, like paints.

However, increasing ventilation comes with a caveat. If you live in an area with high outdoor humidity or significant outdoor pollutants, improving ventilation might worsen indoor air quality. If the air you're bringing inside is filtered to remove harmful particles, there’s little to worry about. But if it isn’t, you may want to settle for moderate ventilation rates.

In addition to ventilation, you can reduce biological contaminants in your home by keeping the humidity between 30 to 50 percent. High humidity promotes the growth of dust mites and mold. Regularly cleaning and drying carpets, as well as maintaining a clean home, will also help minimize biological contaminants.

If you're concerned about the potential dangers of household cleaners, you have two options. First, carefully follow the instructions on the label, use them in well-ventilated spaces, and store and dispose of them properly. Second, choose products made with safe ingredients. If you're unsure, check the label: If a product doesn’t list its ingredients or has warning labels, it’s likely unsafe.

Indoor air pollution has many sources, but so do its solutions. To explore more about this subject, be sure to check out the links provided on the next page.

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