Common Indoor Air Quality Myths Debunked

Misunderstandings about indoor air quality can lead to poor decisions, unnecessary spending, and continued exposure to harmful pollutants. Indoor air can sometimes be more polluted than outdoor air, especially in enclosed spaces with poor ventilation, directly affecting your health, comfort, and daily routines. Common air quality myths can prevent effective action and may contribute to discomfort in individuals with asthma, allergies, or respiratory sensitivities.

From dust mites and volatile organic compounds to mold and tobacco smoke, the pollutants inside your home or workplace can seriously impact your well-being. This article breaks down the most common indoor air pollution myths. It explains what helps improve indoor air quality so you can make informed choices for cleaner, healthier indoor spaces.

Opening windows can sometimes worsen indoor air, especially in poor outdoor air quality. In cities with heavy traffic, industrial activity, or during wildfire events, outdoor air pollution can enter the home and increase exposure to particulate matter and harmful chemicals. During allergy season, letting in outside air can also bring in pollen, pet dander, and other airborne particles that aggravate asthma or respiratory issues. Depending on where you live, relying on outside air for ventilation may not improve indoor air quality.

In areas with good air quality, opening windows on mild weather days can increase air flow and reduce buildup of indoor air pollutants. Short ventilation periods after cooking, using cleaning products, or running equipment that emits strong odors can help flush out polluted air. For best results, check local air quality monitoring tools or apps to identify the cleanest times of day to ventilate. This ensures you’re not replacing one type of polluted air with another.

The idea that houseplants can clean indoor air comes from a NASA study conducted in sealed environments, not typical indoor spaces. In reality, the effect plants have on reducing volatile organic compounds (VOCs) in homes is very limited unless you have a very large number of plants in each room. Indoor air pollution is affected by many sources, including building materials, cleaning products, and poor air flow. Plants can't replace proper ventilation systems or high-efficiency air filters.

While houseplants don’t dramatically improve indoor air quality, they still offer some helpful benefits:

• Add visual appeal to indoor spaces

• May slightly raise humidity levels, especially in dry environments

• Can help reduce stress and support mental well-being

• Absorb small amounts of VOCs, though impact is limited

• Complement other indoor air quality strategies like air purifiers and proper ventilation

Spraying air fresheners may cover unpleasant smells but does not remove pollutants from the indoor environment. Many scented sprays release VOCs and other chemicals contributing to poor indoor air quality. These products may trigger symptoms in individuals with asthma, chronic respiratory conditions, or allergies. Instead of cleaning the air, air fresheners add more airborne particles and chemical compounds to enclosed spaces.

Addressing the root cause of odors is a more effective way to improve indoor air. Safer methods include:

• Removing sources of odor, such as garbage, mold, or dirty pet areas

• Using exhaust fans during cooking or cleaning

• Opening windows only when outdoor pollution levels are low

• Running air purifiers with activated carbon filters to trap odors and pollutants

• Using natural odor neutralizers like baking soda or white vinegar instead of synthetic sprays

Air purifiers can help improve indoor air by removing airborne particles like dust, pet dander, and pollen. Some models include UV lights or ionizers designed to reduce airborne microbes. However, even high-quality units can’t sterilize surfaces or eliminate all germs in your home. Germ-free environments require regular cleaning, good humidity control, and more advanced disinfection systems in healthcare settings. Air purifiers support better air quality but are only one part of maintaining a healthy indoor environment.

HEPA filters effectively trap fine airborne particles, including mold spores and some biological matter, though they do not kill or neutralize microorganisms. Still, they don’t disinfect your space or remove germs from surfaces like counters and doorknobs. Maintaining clean indoor spaces also requires routine handwashing and proper sanitation.

While burning candles or incense may smell pleasant, they do not clean the air. Instead, they release soot, smoke, and volatile organic compounds that can lower indoor air quality. These byproducts can raise indoor particulate levels and may contribute to respiratory discomfort, particularly in sensitive individuals. The scent masks odors but adds more airborne pollutants, making indoor spaces less healthy over time.

For a better indoor environment, consider these safer alternatives:

• Choose unscented or naturally scented soy or beeswax candles with clean-burning wicks

• Limit candle use to short periods in well-ventilated areas

• Address the root cause of odors instead of covering them up

• Use air purifiers with carbon filters for odor removal

• Avoid burning incense in enclosed spaces with poor ventilation

In extreme temperatures, many people seal their homes to conserve energy. While this keeps heat or cool air inside, it also traps polluted air and moisture. Over time, poor indoor air flow leads to high concentrations of pollutants, including carbon dioxide, VOCs, and particles from cooking or cleaning products. Even during hot or cold weather, indoor spaces still need fresh air circulation to maintain safe air quality.

Ventilation systems like exhaust fans and heat recovery ventilators (HRVs) or energy recovery ventilators (ERVs) can exchange indoor air with filtered outside air while retaining temperature. Short bursts of window ventilation, especially during times of lower outdoor air pollution, also help refresh indoor air. Using bathroom and kitchen fans to remove humidity and fumes supports better air quality without sacrificing comfort.

Dusting with a dry cloth might make surfaces look cleaner, but it often worsens indoor air. Dry wiping stirs up dust, pollen, pet dander, and other airborne particles, sending them back into the air instead of removing them. These particles eventually settle again, leaving the indoor environment just as polluted. For cleaner air, it's essential to use methods that trap and remove particulate matter effectively.

To truly reduce dust and improve indoor air quality, use a slightly damp cloth or a microfiber duster that can hold onto particles instead of scattering them. Regular vacuuming with a vacuum that includes a HEPA filter helps capture fine dust and allergens. Reducing clutter also limits areas where dust can build up, helping to maintain better air quality in enclosed spaces.

Changing your HVAC or air purifier filter just once a year isn't enough, especially in homes with pets, high usage, or poor outdoor air quality. Filters trap dust, pollen, and other air pollutants, and when they get clogged, air flow is restricted. This reduces system efficiency and allows pollutants to recirculate, contributing to poor indoor air quality. Most systems require filter changes every 2–3 months or more often, depending on conditions and manufacturer guidelines.

Several signs can indicate it's time to replace your air filter:

• Visible dust buildup on air vents

• A musty or dusty smell in indoor spaces

• Worsening allergy symptoms or respiratory problems

• Filter turning dark grey or brown quickly

• Reduced air flow or HVAC strain

If unsure, check your filter monthly or follow your system’s manual to stay on top of maintenance and improve air quality indoors.

Mold isn’t limited to bathrooms—it can grow anywhere moisture builds up. Basements, attics, crawl spaces, and even behind walls are typical spots where mold can develop, especially when leaks, condensation, or high humidity are present. Mold spores are considered indoor air pollutants and may contribute to respiratory symptoms in sensitive individuals and worsen conditions like asthma. Controlling indoor moisture is key to preventing mold in all parts of the home or building.

Keeping humidity levels between 30% and 50% with a dehumidifier helps prevent mold growth. Fixing plumbing leaks quickly and ensuring ventilation systems are working well reduces moisture buildup. Regular checks in less-visible areas, such as under sinks or around windows, can catch mold early before it spreads and affects indoor air quality.

Even people without existing health issues can be affected by poor indoor air. Breathing in polluted indoor air may lead to symptoms like dry eyes, throat irritation, or fatigue in some individuals. Over time, continued exposure to air pollutants like VOCs, mold, or tobacco smoke may increase the risk of developing respiratory diseases, allergies, or other health problems. Indoor air quality plays a role in your comfort, sleep, and daily productivity—no matter your health status.

Improving indoor air quality benefits everyone in the space:

• Cleaner air can reduce stress, fatigue, and headaches

• Supports better sleep and overall well-being

• Lowers the chance of developing sensitivities or allergies

• Creates a healthier environment for guests or family members with health conditions

• Supports better indoor environments, which may contribute to overall respiratory comfort over time

Many popular beliefs about indoor air pollution sound convincing but don’t hold up under closer inspection. While opening windows, adding plants, or lighting candles may seem helpful, they’re unreliable solutions for improving indoor air. The most effective strategies include source control, consistent ventilation, and high-quality filtration systems.

Since every indoor space is different, taking the time to identify specific issues—such as moisture buildup or high particulate levels—can lead to better results. A well-informed approach backed by proper tools and habits is the key to avoiding poor indoor air quality and supporting long-term health.