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does indoor air quality affect allergies

When you think of pollution, do you envision smoggy outdoor air, smoke-stacks and coal mines? While pollution does exist outdoors and can come from sources outside of the home, indoor air pollution is also a concern. Your home’s HVAC system, carpeting and flooring, paint and furniture can all affect the quality of the air inside of your house. In many cases, poor indoor air quality can have short-term as well as long-term health effects. Some of those long-term health effects include allergies.

If you have ever wondered why your allergies are so bad or why your allergies are worse indoors, you could be allergic to something in your home. Learn more about indoor air quality and allergies, including what types of allergens are more common indoors and how you can get rid of indoor allergies.

indoor air quality

What Is Indoor Air Quality?

Indoor air quality describes the condition of the air inside your home and surrounding your home. When people mention indoor air quality (IAQ), they usually do so with a focus on how IAQ affects the health of the people who use or live in a house or building. They also usually focus on ways to improve IAQ to preserve or improve people’s health.

IAQ can have either immediate effects on people’s health or long-term health effects, which develop after years of exposure to certain pollutants indoors. Immediate effects show up right after someone is exposed to an irritant indoors. For example, if new carpeting is installed in a house and the carpet off-gasses volatile organic compounds (VOCs), a person might develop a headache or might cough or sneeze after exposure to the VOCs. Opening the windows to the room with the new carpet can help the VOCs dissipate quicker, easing a person’s discomfort.

Long-term health effects can include chronic respiratory problems, which might develop after years of exposure to certain VOCs or exposure to high levels of mold in the air. Cancer can also be a long-term health effect caused by poor indoor air quality.

Several things can affect or reduce indoor air quality in a home. They include:

  • Smoking indoors.
  • Appliances that burn fuel, such as a wood-burning fireplace or a furnace that is not properly ventilated.
  • Excess humidity or moisture, which creates a hospitable environment for mold growth.
  • Carpeting, flooring and paint.
  • Cleaning products.
  • Personal care products, such as hairspray or cologne.
  • Burning candles.
  • Houseplants.
  • Pets.

Can Your Indoor Air Quality Cause Allergies?

Like pollution, it is often assumed that allergens come from the outdoor air. While it is true that many people are allergic to things in the outside world, such as pollen, allergens can also exist inside a home or other buildings. Millions of people have some sort of allergy to substances found indoors.

An allergen is any substance or material that is normally harmless but that the body mistakes for a dangerous intruder. In response to exposure to an allergen, the body’s immune system produces antibodies. The antibodies attack the substance, triggering a response from the body’s immune system. Depending on the type of allergic reaction a person has to an allergen, the response can cause coughing, sneezing, a runny nose or a feeling of scratchiness in the throat, nose or eyes. In some people, the allergic reaction can trigger an asthma attack, making it difficult for them to breathe.

Some types of allergens are more common indoors than others. A few of the most common indoor allergens include:

  • Dust mites: Dust mites are microscopic organisms that live inside many homes. They often live on soft surfaces, such as mattresses and upholstered furniture. Dust mites feed on skin cells that are found in dust and prefer to live in areas that are warm and moist. While they do not bite or sting, they do produce a substance that many people are allergic to. About 80% of homes in the U.S. contain the allergens that dust mites produce.
  • Mold: Like dust mites, mold thrives in humid and warm areas of the home. Mold can grow in bathrooms, damp basements or on walls or floors that are near leaking pipes. Mold releases spores into the air that can trigger allergic reactions in sensitive people. Some mold types are more likely to cause allergic reactions or asthma than others. Alternaria, Cladosporium and Penicillium are some of the molds that are most likely to cause allergies.
  • Pests: Cockroaches are examples of indoor pests that can trigger allergic reactions in sensitive people. Some people are allergic to cockroach droppings or to cockroach saliva and skin. Like dust mites, cockroaches like to live in areas that are moist and warm. One way to control cockroaches is to keep areas dry, such as by fixing leaks and by drying sinks and tubs after use. Keeping food out of the reach of roaches can also deter them.
  • Pet dander: Although many people assume that they are allergic to pet fur, it’s actually the dander, or skin cells of pets, that people are allergic to. Some people are also allergic to pet saliva or urine. The protein that pet dander, urine or saliva contain can trigger an immune response in allergic people, causing symptoms such as sneezing, coughing and a runny nose. Some people experience a worsening of their asthma when they are near pets.


Some substances can affect indoor air quality and cause discomfort or allergy-like symptoms in people but are not actually allergens. For example, some people experience irritation due to exposure to fragrances found in cleaning products or personal care products. Others are sensitive to smoke from cigarettes or other tobacco products.

household allergy

Household Allergy Symptoms

Indoor allergens often cause symptoms of allergic rhinitis, also known as hay fever. Usually, allergic rhinitis is chronic or perennial when it is triggered by indoor allergens,  meaning a person can have symptoms throughout the year, rather than during a particular season. Allergic rhinitis can occur when a person breathes in an allergen, such as mold spores, pet dander or dust mite droppings.

Some of the most common symptoms of allergic rhinitis include:

  • Itchy eyes, mouth, skin or nose.
  • Runny nose.
  • Stuffy nose or nasal congestion.
  • Sneezing.
  • Trouble sleeping and feelings of fatigue.


Exposure to indoor allergens can also trigger symptoms of asthma in certain people. Asthma is a condition that causes the airways to swell or become inflamed. When the airways are swollen, it can be difficult for a person to breathe. Some symptoms of asthma that can occur as a result of indoor allergens include:

  • Wheezing.
  • Chest pain or tightness.
  • Shortness of breath.
  • Coughing.


A person can also experience a reaction to an indoor allergen on their skin, such as a rash or hives. If the allergen gets into the eyes, it might cause redness and itchiness.

Can Allergens Be Removed From Indoor Air?

If you want to breathe easier when you are inside your home and reduce your allergy symptoms, you have options.

Here are some ways to remove allergens and improve air quality in your home:

  • Increase ventilation: One way to improve air quality indoors is to increase the amount of fresh air that makes its way into the house. In some cases, that can be as simple as opening a door or window on a nice day to let some air in. Improving ventilation can also mean running an exhaust fan in the bathroom during and after taking a shower to pull humid air outside of the house. In the kitchen, an exhaust fan can increase ventilation by pulling smoke and cooking fumes out of the house. Depending on the type of HVAC system you have installed in your home, it might have features that are designed to improve airflow and ventilation, without requiring you to open windows or doors.
  • Reduce humidity: Many indoor allergens do best in humid or moist areas, such as bathrooms, bedroom linens and basements. Reducing the humidity in your house can create an environment that is inhospitable to dust mites, mold and cockroaches. You can install and run a dehumidifier in certain rooms, such as in the basement or bathroom. Running an exhaust fan in the bathroom or opening the window during showers can also help to lower humidity levels.
  • Filter allergens: Your furnace, air conditioner or HVAC system most likely have a filter installed to catch dust, hair and other allergens to keep them from circulating throughout your home. To get the most use out of your air filter, it is important to change it often. At the very least, change the filter once per season. If you have pets, it might be a good idea to replace the filter even more frequently, such as once a month or every two months.
  • Purify the air: Air purification systems work to clean the air in your home in one of two ways. Some use ultraviolet (UV) light to kill mold and other germs, while other purification systems use ionic technology. Ionic technology creates positive and negative ions, which makes particles larger so that they are more likely to get trapped in an air filter or become heavy enough to fall to the floor or onto another surface, where they can be swept or vacuumed up.


indoor allergens

Additional Ways to Reduce Indoor Allergens

Along with removing allergens from the air inside of your home, there are things you can do to minimize the number of allergens in your home in the first place. If you or anyone you live with experiences allergy symptoms that might be connected to dust mites, pet dander, mold or cockroaches, try these ideas to help to minimize or eliminate allergens:

  • Rethink carpeting: Wall-to-wall carpeting tends to be a magnet for dust mites and pet dander. If you have allergies or asthma, you are likely to see an improvement in your symptoms if you trade carpets for hard flooring options, such as hardwood, tile or laminate. If you like the feel of a soft rug beneath your bare feet, you can use throw rugs throughout the house. Choose throw rugs that are machine washable or that you can pick up and shake out regularly.
  • Use pillowcase and mattress covers: Over time, pillows, mattresses and other types of cushions can become a haven for dust mites. One way to keep dust mites out of your pillows and mattresses is to use washable covers over the top of them. Wash the covers regularly, using hot water. Dry them on high heat.
  • Wash bed linens often: In addition to washing pillow and mattress covers regularly, it is also a good idea to wash sheets and pillowcases often, preferably once a week, to remove accumulated pet dander, dust mites and other potential allergens. Use hot water and a hot dryer for best results.
  • Vacuum regularly: Even if you do not have wall-to-wall carpeting, you will want to get in the habit of vacuuming your house regularly, at least once a week. If you have pets, you might need to vacuum more frequently. Pick a vacuum that has a good filter to catch any allergens that get sucked up.
  • Clean from top to bottom: When you clean your home, start at the top, near the ceiling and on high surfaces, and work your way down, to make sure you catch as much dust and dander as possible.
  • Keep your pets out of certain rooms: If you have pets and are allergic to them, it can be difficult to keep dander out of the house. Even if you keep your pets outside, there is a chance that their dander will make its way indoors. A compromise might be to restrict your pets’ access to certain rooms, such as the bedrooms. That way, you will be able to get a peaceful night’s sleep relatively undisturbed by pet dander.
  • Reconsider upholstered furniture: Like carpeting, fabric-covered furniture can be a magnet for indoor allergens. You do not need to swap your overstuffed couch for a hard bench, though. A leather or imitation leather couch can be just as comfortable but less likely to trap allergens.
  • Wash dishes daily: Washing the dishes every day, or preferably, after each meal, can help to create an environment that is less friendly to cockroaches. Washing and drying dishes can also reduce the likelihood of mold growing in the kitchen.
  • Keep the area around sinks dry: Cockroaches go where there is water. Drying the inside of sinks and the countertops around sinks each day will deprive the pests of the water they need. Keeping the counters and sinks dry can also cut down on mold growth.
  • Put food away: Putting food away, either in tightly-sealed containers in the pantry or the refrigerator, will keep pests from getting into it. When there is no food around for them, pests are also less likely to come into your kitchen.
  • Do not overwater houseplants: Some types of houseplants can help to clean the air, but overwatered soil can create an environment that is hospitable to mold. Do not water your plants so much that the soil stays saturated.


indoor air quality

SMO Energy Can Help Improve Your Home’s Indoor Air Quality

If you are concerned about indoor allergies, improving the air quality inside your home can help you and your loved ones breathe easier. SMO Energy sells air cleaning systems and can help you choose the air purifier that will work best in your Southern Maryland home. We also perform HVAC installation and replacement and can upgrade your current system to one that provides better filtration, humidity control and ventilation. To learn more, contact us today to schedule a free in-home energy consultation.