When you think about air pollution, you may picture hazy smog hanging over a city’s skyline, or perhaps a factory tower belching out black smoke. But did you realize the air inside your home could be even more dangerous than the outdoor air? According to the U.S. Environmental Protection Agency, the concentrations of air pollutants such as volatile organic compounds and chemicals from cleaning products may be up to five times higher indoors than they are outdoors. 

With more and more Americans spending as much as 90% of their time indoors, indoor air quality should be a significant concern for you and your household. Air contaminants can lead to health concerns like headaches, dizziness and persistent fatigue. Prolonged exposure to poor-quality air can cause or worsen respiratory conditions like allergies and asthma. If you and your family feel chronically ill without understanding why, indoor air quality might be to blame. 

In this guide, we’ll explain everything you need to know about indoor air quality and its impacts on your health, and offer some solutions you can use to create a healthier, happier home.

Short-Term Effects of Poor Indoor Air Quality 

With every breath you take, you’re also inhaling any pollutants that may be lingering in the air around you. Indoors, those could include pesticides, mold, pet dander, cigarette smoke and off-gassed chemicals from furniture, cooking and cleaning products. 

In some cases, poor air quality can begin causing issues almost immediately. Common short-term effects include lightheadedness, tiredness, confusion, headaches, nausea, and irritation of the eyes, nose and throat. Some people may also experience sneezing, wheezing or asthma attacks.

Long-Term Effects of Poor Indoor Air Quality 

Brief exposure to contaminated indoor air usually causes mild symptoms that go away after leaving the affected space. With repeated, long-term exposure, the dangers may increase significantly. Being in the presence of indoor air pollution for longer periods could lead to health conditions such as mood changes, respiratory and cardiovascular diseases, neurological disorders and some forms of cancer. Airborne pollution is also more dangerous for elderly people, young children and pregnant people, plus anyone with compromised health.  

To make matters worse, almost anyone can be highly susceptible to these health issues, even people who are generally healthy with no chronic conditions. That’s primarily because most Americans tend to spend the bulk of their time indoors, whether at home or at work.

What Are Some of the Most Common Indoor Contaminants?  

You want the best for yourself and your family, and that includes protecting your home from threats. However, we tend to focus our attention only on risk factors we can see and touch, which is why so many people ignore indoor air quality. 

Pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in homes. Examples of these are furniture, carpets, cooking, secondhand tobacco smoke, paint and cleaning products. Some of these emit harmful air pollution continuously.


Biological air pollutants are, or are byproducts of, living things. Many of them are tiny enough for you or your family to unknowingly inhale, which can trigger allergic reactions such as sniffling, sneezing, coughing, itchy or watering eyes, lethargy, dizziness, fever and digestive issues.


Poorly maintained central air conditioning systems can become ideal breeding grounds for mold and mildew because these biological contaminants thrive in moisture-rich environments such as cooling coils, humidifiers and condensate pans. Scientists have identified more than 100,000 mold species, and while not all of them represent health hazards, identifying toxic mold can be challenging without the help of a trained professional. If you discover mold growth within your HVAC system or anywhere else in your home, it’s best to call an experienced technician to inspect the area and determine if your home requires treatment.

Dust Mites 

Household dust is more than merely a nuisance – it’s an invitation to dust mites to share your home with them. Dust mites feed on dead skin cells and other things that make up dust, and the mites and their waste products add to the dust. Since dust mites are microscopic, most people have no idea how many mites might be living in their home. The mites don’t bite, but they can affect your indoor air quality and cause allergic reactions. One simple step you can take to reduce dust mites is to dust more often. Another thing you should consider is controlling your home’s humidity levels. Dust mite populations increase in high-humidity environments.


Pollen is one of the most common allergy triggers worldwide. Many seasonal allergy sufferers stay inside when the forecast calls for high levels of pollen from plants like grass and ragweed, but pollen can still circulate throughout your HVAC system and affect your indoor air quality. For example, pets’ fur can trap pollen, which they bring inside with them. You and your family can also track pollen inside on your shoes and clothes, and even in your hair. You can take steps to limit pollen in your home by dusting and vacuuming frequently. You may want to invest in a HEPA vacuum cleaner and air filters.


Chemicals’ ability to cause health effects varies greatly. We know some, like carbon monoxide and benzene, are highly toxic, while others seem to have no apparent adverse effects. Signs and symptoms associated with exposure to chemicals include eye and respiratory tract irritation, headaches, dizziness and memory loss.

Volatile Organic Compounds 

In a phenomenon called off-gassing, many items in your home release gases known as volatile organic compounds. VOCs are consistently higher indoors than outdoors. VOC sources can include new furniture, mattresses, carpet and building materials; paint and varnish; cleaning products; scented air fresheners; and pesticides. VOCs may react with ozone to produce secondary pollutants, some of which can cause irritation and poor air quality. 


Formaldehyde is a colorless, noxious-smelling and irritating VOC, and can cause cancer in humans. You may remember its pungent odor if you ever dissected a frog in biology class, since anatomists and embalmers use formaldehyde as a preservative. In your house, possible formaldehyde sources include pressed wood products such as particleboard and fiberboard. Some adhesives and glues also contain formaldehyde, and it is one of the hundreds of toxic chemicals present in cigarette smoke.


Lead is a toxic metal that was once a standard component of many everyday household products, including paint and gasoline. Lead is a naturally occurring element. Unlike many other air pollutants, lead levels do not diminish or dissipate over time.

In the past, manufacturers added lead to gas, paints, sewage pipes, ceramic glazes and fertilizers. Since the late 1970s, nationwide elimination of lead in gasoline and paints has drastically reduced lead pollution in the U.S. However, if you have an older house built before 1978, lead-based paint may be a significant source of air pollution inside your home. Lead-contaminated soil tracked in from the outside may also be a cause for concern if you live near a lead smelter or industrial area.


Radon is a radioactive gas found naturally underground, especially in areas where the bedrock contains excessive uranium. It can diffuse through the soil and usually enters buildings through cracks in the floors and walls or gaps around pipes. For people with wells, trace amounts of radon may also be present in their drinking water.

In small quantities, radon is usually harmless. However, its presence in indoor air can lead to lung cancer. After smoking, radon exposure is the second leading cause of lung cancer in the U.S. The EPA estimates that one in every 15 homes in the United States could have elevated radon levels.


Combustion pollutants are the toxins released when you burn any fuel, such as wood, natural gas, kerosene, charcoal or tobacco. Combustion pollutants affect indoor air quality and make people more vulnerable to illnesses ranging from mild to severe.


If anyone in your household smokes indoors, they are putting everyone’s health at risk. The EPA has categorized secondhand tobacco smoke as a Group A carcinogen because it contains thousands of dangerous chemicals. Therefore, smokers affect everyone around them with their unhealthy habit. Exposure to tobacco smoke can multiply someone’s chances of developing severe issues such as cardiovascular disease and cancer. It can also cause asthmatic people to experience more frequent and severe asthma attacks. If you smoke, the best thing you can do for your and your family’s well-being is to quit. 

Carbon Monoxide 

Carbon monoxide is a dangerous chemical combination that may emanate from gas stoves and heaters, wood-burning fireplaces, cigarette smoke and gasoline-powered vehicles and equipment.  Because it is impossible to see, taste or smell the fumes, you may not be aware that CO is present in your home until it’s too late. At low concentrations, carbon monoxide can cause fatigue in healthy people and chest pains among people living with heart disease. In higher amounts, CO can lead to impaired vision and coordination, dizziness, disorientation, headaches and flu-like symptoms, including nausea. Extremely high concentrations of CO can be fatal.

What Can You Do to Limit Common Indoor Contaminants? 

Now that you understand what pollutants adversely affect your indoor air quality and your family’s well-being, what steps should you take to limit these hazards? Achieving this goal may require you to change some habits and behaviors. For instance, if you smoke or vape indoors, quitting is one of the most considerate things to do for yourself and everyone around you. 

You can also do yourself a favor by switching from harsh, chemical-laden cleaning products to organic ones, or making all-natural, DIY vinegar-based cleaner at home. If you or any member of your household has allergies or asthma, consider investing in a vacuum cleaner with a built-in HEPA filter, and vacuum your floors and furniture daily to minimize the amount of allergens circulating through your air ducts.

How to Improve Your Indoor Air Quality 

Most of the air pollutants we’ve discussed are colorless, odorless and invisible to the naked eye. While it’s probably not possible to eliminate all the allergens inside your home, you can reduce the number – and your exposure to them – by making some simple adjustments.

Change Your AC Filter 

Your AC air filter plays a central role in improving your indoor air quality because it’s designed to trap allergens and other contaminants. Routine  filter changes are crucial, especially if anyone in your family struggles with respiratory issues like allergies or asthma. 

Changing your AC filter is a quick, DIY chore that only takes a few minutes and doesn’t require any specialized tools or training. Set a reminder on your smartphone to change your filter every three months – more frequently during peak cooling season or if you have furry or feathered family members.

Don’t Forget About Other Air Filters 

Have you ever stopped to consider all the various filters that work to 

improve your indoor air quality? Aside from your AC filter, you likely also have filters in appliances like your vacuum cleaner and clothes dryer. If you use a room air purification system, that also uses a filter. When you change out your AC filter, don’t forget to check these filters and replace them if necessary

Check Your Air Ducts 

Central HVAC systems rely on a network of air ducts to direct heated or cooled air into your home. However, dust, pollen, pet dander, mold and other pollutants can accumulate in your ductwork. It’s smart to add professional duct cleaning and inspection services to your preventive HVAC maintenance checklist to ensure your HVAC system is only circulating fresh, clean, healthy air through your ductwork and air vents.

Use Cooking Vents 

Cooking nutritious, balanced meals for your family can keep everyone healthy and support your active lifestyle. However, if you have a gas stove, it can release carbon monoxide and nitrogen oxide into the air. Electric stoves can also emit smaller quantities of indoor air pollution. While you’re preparing tasty, healthy foods, remember to turn on your cooking vent. If you have a kitchen window, you can also crack it open whenever you’re using your stove or oven. 

Keep Your Rugs and Carpets Clean 

Cleaner homes are healthier for everyone, because thorough indoor hygiene practices can dramatically reduce dust and animal dander circulating throughout the indoor air. Because upholstery and carpet fibers can trap contaminants like pet dander and pollen, vacuum your floors and furniture at least once or twice per week with a HEPA filter vacuum cleaner. You should also routinely wash bedding, drapes and other allergen-attracting furnishings, especially if your household includes pets. If anyone in your family has allergies or asthma, keeping a tidy house and cutting down on clutter can help ease their symptoms.

Control Humidity in Your Home 

Excess humidity can make you feel uncomfortable, hot and sweaty. But did you know this unwanted moisture can also damage your wood flooring and furniture? Humidity also causes condensation, which can promote mold and mildew growth. In extreme circumstances, excessive moisture can undermine your home’s structural integrity. The easiest way to determine if your house is too humid is to buy an inexpensive hygrometer, which is a device that measures indoor humidity levels. If you measure the air in your home and find it is higher than 40 to 50%, you can reduce humidity by using your air conditioner and investing in a dehumidifier.

What About Houseplants? How Do They Affect Indoor Air Quality? 

Realizing how many invisible air pollutants might be circulating throughout your air ducts might make you anxious about your family’s safety. Luckily, there’s an easy, attractive and all-natural way to clean the air in your home: houseplants. In 1989, NASA published an extensive study of houseplants’ air-scrubbing abilities and tested their effectiveness at removing contaminants such as formaldehyde, smoke, radon and organic chemicals from enclosed spaces. 

The NASA researchers concluded that plant roots and their associated microorganisms gradually neutralize air pollutants and convert them into new plant tissue. Based on this knowledge, you can use household plants for more than purely decorative purposes.

20 Plants You Can Use to Improve Your Home’s Air Quality

Plants absorb some of the particulates in the air while taking in carbon dioxide, which they process into oxygen during photosynthesis. They are also naturally beautiful and can complement any decor! Here are 20 plants that purify the air in your home.

Devil’s Ivy or Pothos (Epipremnum aureum) 

Pothos, also known as devil’s ivy, is a low-maintenance plant that thrives almost anywhere. It has large, heart-shaped leaves with a waxy texture. The leaves are dark green, often with yellow or gold accents. Pothos plants prefer bright, indirect light, but can grow well in darker conditions. Water your pothos when its soil feels dry to the touch, and cut back the vines if they get excessively long. You can also propagate pothos plants by putting the cut ends in water and planting them after they grow roots.

Dwarf Date Palm (Phoenix roebelenii) 

Dwarf date palm trees are a subtropical species that can grow five to six feet tall indoors. The trees grow small, yellow flowers that become small, purple fruits. To care for your pygmy date palm, be sure to maintain a regular watering schedule and plant this tree in sandy, well-drained soil in an area of sun all the way to full shade.

Peace Lily (Spathiphyllum) 

Peace lilies have generously sized, dark green leaves with graceful white flowers. While peace lilies are not true members of the lily family, they are a lovely, easy-care houseplant. They can grow in shade or partial shade, and even in fluorescent light if you are keeping them in an office. The plant will droop to let you know when it needs watering. 


Philodendron is one of the best houseplants for indoor air quality. These plants have large, glossy leaves that will add an exotic touch to any home decor. Philodendron plants prefer natural light, plenty of moisture and warmth. If the weather allows, giving your philodendron some time outside will help it thrive.

Spider Plant (Chlorophytum comosum) 

Spider plants are adaptable, forgiving and one of the easiest plants to grow. If you’re new to indoor plant care but still want to beautify your space and improve your indoor air quality, a spider plant is an excellent choice. With well-drained soil and bright, indirect light, they will flourish. Spider plants also benefit from occasional pruning.

Chrysanthemums (Chrysanthemum morifolium) 

Chrysanthemums are perennial plants and members of the daisy family. Though you may associate them with autumn, it’s best to plant them in the early spring. Mums come in many bright colors and have bluish-green leaves. These flowering plants can remove many harmful indoor pollutants, including formaldehyde, benzene and xylene. They’re also hardy and easy to care for, and some varieties thrive in indoor pots.

Rubber Plants (Ficus elastic)

Rubber trees make excellent houseplants. They do well in low-light conditions, and help clean pollutants from the indoor air. With its large, shiny leaves, a rubber plant can add a dramatic accent to any room. Water every one to two weeks, allowing the soil to dry out between waterings. For maximum air-purifying benefits, periodically wipe the leaves down with a damp cloth to keep their pores open.

Boston Fern (Nephrolepis exaltata v. Bostoniesis) 

Boston fern care is simple. These plants have low sunlight needs and require moist, well-drained soil. Because ferns like warm, humid conditions, regularly misting your fern is essential to keep it healthy. Plan to water frequently to keep the soil from drying out.

Areca Palms (Chrysalidocarpus lutescens) 

Areca palms resemble bamboo and are native to Madagascar. When grown outdoors, they make an excellent privacy screen, but they are also beautiful indoor plants. Like many palms, areca palms like moist soil. However, they can’t tolerate being waterlogged, so be careful not to overwater them.

Pineapple Plant 

If you enjoy indoor gardening, a pineapple plant could be a fun project for you to take on. This herbaceous perennial has long sword-like leaves growing in a spiral around a central stem. Each pineapple plant produces one flower stalk. After the flower blooms, the edible pineapple fruit emerges. 

Dracaena “Janet Craig” (Dracaena deremensis) 

Despite their tropical origins, dracaenas require little water and grow well in low light. Water thoroughly, allowing the top inch of soil to dry out between waterings. If overwatered, a Janet Craig plant’s leaves will turn yellow and fall off. Brown leaf tips indicate dry soil or a buildup of salts.

Ficus/Weeping Fig (Ficus benjamina) 

Weeping fig is a stylish plant with slender branches growing from a light gray trunk. When grown indoors, they rarely grow taller than three to six feet. You might want to look for one with a braided trunk for more aesthetic appeal. Weeping fig is one of the best plants for improving indoor air quality. It is one of the best plants for removing airborne toxins such as formaldehyde and benzene. 

Snake Plant/Mother-in-Law’s Tongue (Sansevieria trifasciata) 

Snake plants are succulents with characteristic long, sword-shaped leaves. The ancient Chinese were the first people to cultivate snake plants because they believed the gods would bestow blessings on those who cared for these plants. The snake plant was one of the subjects of NASA’s landmark 1989 study on how plants can purify indoor air. 

(Aloe vera or A. barbadensis) 

Aloe vera is a succulent plant with many healing properties. Besides being a low-maintenance choice, succulents are also cute and trendy. In addition to its air-scrubbing properties, aloe vera also has a range of healing benefits. You can use the gel from the leaves to soothe burns and cuts.

English Ivy (Hedera helix) 

Ivy is an attractive, bright-light houseplant. The leaves are green, often tinged with white, yellow or cream colors. Without sufficient light, the leaves will droop and become sickly-looking. The ivy plant will also be more vulnerable to pest infestations. Ivies prefer slightly dry soil, so do not water your ivy plant again if you feel any moisture in the potting soil.

Flamingo Lily/Fleur (Anthurium andraeanum) 

The flamingo lily is a tropical plant that can add a dramatic flair to your home decor. Average home temperatures and humidity levels mimic flamingo lilies’ natural habitat. This plant has a bright red flower surrounded by green, glossy, heart-shaped leaves. To keep your flamingo flower healthy, put it in bright, indoor sunlight and water it when the top inch of soil dries out.

Lady Palm (Rhapis excelsa) 

The lady palm, also called the miniature fan palm, is a small plant that rarely grows taller than six feet when planted indoors. These plants are highly tolerant of low-light conditions and fit easily into the corner of most rooms. Lady palms thrive in the same indoor conditions you would also be comfortable in.

Chinese Evergreen (Aglaonema) 

Even if you don’t have a green thumb, a Chinese evergreen will do well in almost any growing conditions. Known as one of the hardiest houseplants, Chinese evergreens are easy to care for and provide your home with natural beauty year-round. Older Chinese evergreen plants sometimes produce white flowers similar to peace lilies.

Kimberly Queen Ferns (Nephrolepis obliterata) 

Native to Australia, the Kimberly queen fern is a striking plant with upright fronds. These plants require a bit of special attention to thrive indoors, including consistent moisture and humidity levels. Depending on how much light your Kimberly queen fern receives, you may need to water it a few times per week to keep it healthy. 

Bamboo Palm (Chamaedorea seifrizii) 

While most tropical palm species need bright light to flourish, the bamboo palm can thrive in lower light. As an air-scrubbing plant, the bamboo palm can eliminate carbon monoxide, formaldehyde and benzene from your indoor air. It also brings a little tropical flair to any room that needs brightening up.


If you’re ready to learn more about improving indoor air quality in your home, our expert team at Above & Beyond HVAC Services is here to help. Our Delaware heating and cooling experts always go the extra mile for our customers throughout our extensive service area. We’ve been serving our neighbors for more than two decades with preventive maintenance plans, 24/7/365 emergency repair services and thorough installation of new, energy-efficient heating and cooling equipment. We are so confident about the quality of our work that we stand behind it with a 100% satisfaction guarantee. To schedule a service appointment or request a service quote, reach out to us today.