What is IAQ and Why is Indoor Air Quality Important?
- Jen Stout
- 16 hours ago
- 10 min read
Indoor air quality (IAQ) matters because the air inside your home is often more polluted than the air outside — sometimes 2 to 5 times more, according to the EPA. Most people spend around 90% of their time indoors, which means poor IAQ is one of the most significant — and most overlooked — environmental health risks families face. Common indoor pollutants include volatile organic compounds (VOCs) from furniture, paint, and flooring; formaldehyde from manufactured wood products; mold from moisture; and particulates from dust, pet dander, and outdoor air infiltration. Short-term exposure causes eye irritation, headaches, and worsened asthma. Long-term exposure is linked to respiratory disease, organ damage, and cancer.
According to the U.S. Environmental Protection Agency (EPA), indoor air can be 2 to 5 times more polluted than outdoor air, and in some cases, even higher.
The good news: IAQ is largely within your control. This guide covers the main causes of poor indoor air quality, how to detect it, and the most effective steps to improve it — starting today.
What is Indoor Air Quality (IAQ)?
Indoor air quality (IAQ) is the condition of the air inside buildings, including homes, offices, and schools. It is influenced by pollutants such as dust, mold, pet dander, volatile organic compounds (VOCs), and carbon monoxide, as well as factors like ventilation, humidity, and temperature.
Most of us spend about 90% of our time indoors. Chillin' out, maxin', relaxin', all cool. But, there's a chance that you're being exposed to harmful pollutants - from inside your own home.
That's why we put together this quick guide to share why indoor air quality is important and how to improve the IAQ in your home today!
>> IAQ Meaning
Indoor air quality is the air quality inside or around your home and other buildings. This includes: your office, schools, local churches, gyms and more.
We're used to thinking of pollution as something that happens outside. Yet, organic pollutant levels are 2 to 5 times higher inside your house than on the outside, according to the EPA. And, it doesn't matter whether your home is in a crowded city or a wide-open rural area.
That's because what's inside your home determines your indoor air quality.
Our favorite furnishings might look lovely on the outside. But, there are a lot of chemicals used during the production of our much-loved items that we're unaware of. These chemicals end up releasing gasses called volatile organic compounds (VOCs).
Think about that “new car smell” or the last time you unwrapped something new.
Yeah, that was off-gassing.
VOCs can be found in paints, solvents, furniture, wallpaper and more. Everything from your much-loved couch to the dining table you sit around for dinner. And, they stay in the air for years to come. Even worse, they can harm both people and animals when they're inhaled.
Why is Indoor Air Quality Important?
The most affected by this are children and older adults. Especially people who are sensitive or have allergies and those with chronic illnesses.
Why Indoor Air Quality Matters for Your Health
Poor indoor air quality can lead to both short-term and long-term health effects.
Short-term effects include:
Headaches and dizziness
Eye, nose, and throat irritation
Fatigue and difficulty concentrating
Long-term effects may include:
Chronic respiratory diseases
Worsening asthma and allergies
Increased risk of cardiovascular disease
What Causes Poor Indoor Air Quality?
Several common household factors contribute to indoor air pollution:
Inadequate ventilation
Household cleaning chemicals
Tobacco smoke
Mold and moisture buildup
Dust and pet dander
How to Improve Indoor Air Quality (Quick Wins)
You can significantly improve your indoor air quality by taking simple steps:
Increase ventilation by opening windows or using exhaust fans
Use a high-quality air purifier with HEPA filters
Control humidity levels to prevent mold growth
Regularly clean and vacuum your home
Avoid products with strong chemical emissions
What Causes Poor Air Quality in Homes or Indoors?
Now that we're all wanting a zen-like home, let's take a look at the leading causes of poor indoor air quality.
>> The Classics – Lead and Asbestos
These might be the two you’re most familiar with. Asbestos is a harmful substance mainly found in insulation materials. Lead can be found in paints and solvents. Both of these toxic substances were used in homes built pre-1980s.
Yes, these substances are dangerous to your health, but only if you’re exposed to them. If they’re properly sealed up inside your walls or by extra coats of paint they’re often OK to leave alone. Check the interior structure and surfaces of your home to make sure they’re in good condition.
If you decide to remove either asbestos or lead from your home, we recommend you work with a professional. Someone with experience in removing either substance.
>> Mass Manufacturing Mayhem - Formaldehyde
This colorless and flammable gas is one of the worst VOCs out there. In higher concentrations, formaldehyde can cause cancer and other health problems. It has a distinctive smell, often likened to vinegar or burnt matches.
Formaldehyde is used in almost all mass-manufactured products. It also acts as a preservative in construction materials. There are other harmful VOCs like benzene and toluene that are used in a lot of our household items. Anything from your paints and flooring to your air fresheners and cosmetics.
>> Moisture and Messy Mold
Mold thrives in warm and damp areas. The simple leak from the faucet you keep forgetting to repair. Or, just plain high humidity weather entering your home.
High indoor humidity creates the ideal environment for mold to grow. Too much moisture can even lead to more dust mites in your home and cockroach infestations (eek!).
Indoor mold exposure can trigger irritation to your eyes, nose and throat. It can also lead to allergic reactions and asthma. Those of us with weakened immune systems can suffer from more severe health problems.
>> The Danger Duo – Dust and Dander
Dust is on our most wanted list for skin irritation, coughing and allergy triggers. These tiny particles carry skin cells, mold spores, biotoxins and other chemical pollutants. It’s not always possible to see every corner of your home if you’ve got large pieces of furniture against the wall. It could be worth periodically cleaning behind wardrobes, cabinets and dressers. Anywhere the dust mites could be hiding.
Pet dander can also contribute to dust in your home. If you do have a pet, you can limit the build up of dander by regularly brushing them and vacuuming more often. It’s super easy for pet hair to get caught up in carpet too. You might want to reconsider your flooring if you have a couple furry family members at home.
>> Air From Outside
It’s a hot and stuffy day and you open up your windows to let some fresh air into your home. You’re turning on the exhaust fans in your kitchen while you’re cooking dinner. After taking a long hot shower in your bathroom, you leave the windows open. Or, you’re just coming and going through your front door.
All of these normal and everyday movements draw in outside air into your home. There are outdoor pollutants, like pollen and carbon monoxide, drifting indoors. Through windows, doors, small crevices in the attic or your HVAC system.
So, how do you get around that? Leave windows and doors open on days when pollen levels are low. You can check online for air pollution and humidity warnings too.
Did You Know? Radon exposure is the second leading cause of lung cancer in the US, right after smoking. This naturally occurs as a result of uranium in the soil breaking down over time. Radon is a colorless, tasteless and odorless radioactive gas. It can enter your home over time through cracks and small openings. Found in every state, limited exposure to radon is inevitable. But it becomes dangerous when trapped indoors.
Signs of Poor Air Quality in Homes or Indoors
There are different types of harmful pollutants that could be lurking indoors. How do you know if they’re in your home?
>> Air Quality Meters
You can buy an air quality meter to measure the level of VOCs or CO2 in your home. Meters can tell you important information about your VOC levels. There are meters that measure your total volatile organic compounds (TVOC) indoors. Some VOC meters can be used to measure formaldehyde levels in particular.
Keep in mind: Brand new items off-gas unless you’ve bought a non toxic, zero-VOC alternative. Particle board, OSB and MDF are major sources of formaldehyde fumes from furniture! Instead, choose furniture made from sustainable, natural materials.
So, VOC meters are not always 100% accurate. And some harmless things like vinegar will register as a VOC. However, they’re still a great way to assess if you have a serious VOC issue in your home.
CO2 sensors let you know if there’s enough ventilation in your home. A high level of CO2 would indicate that there’s not enough fresh air in your home to sustain the occupants inside.
>> Visual Signs at Home
There are a few things you can routinely check around your home to check for signs of poor air quality.
Condensation on Windows: condensation often appears on windows and glass doors at home. It can be easier to spot as the weather cools down outdoors and you turn on the heating at home. Condensation can lead to mold growth, so it's important to keep in check.
Mold Growth: Any dark or fuzzy spots on your window panes or walls can be signs of moisture issues in your home. Mold can also grow on materials like grout and sheetrock too.
Dust Build-up: Dust can build up on your sofa, tables, floors and baseboard. Any and all surfaces need to be routinely cleaned and dusted to prevent dust build-up.
>> Physical Symptoms
We’re definitely not as gifted as our canine pals, but our noses can still sense when something’s in the air. If you’re smelling a pungent, sweet aroma, this could be coming from petro-based solvents. A musty indoor smell coming from the basement could be a telltale sign of mold growing.
You might find yourself with unusual throat, skin or eye irritation at home. This could be a short-term effect if you haven’t cleaned in a while or the beginnings of a serious health issue. Trust in your instincts – there might be something up with your indoor air.
How to Improve Indoor Air Quality
So, you’re looking around your home, wondering what toxins are keeping you company. And, how you’re gonna get rid of them. In the meantime, we’ve got some tips on the best way to improve air quality in your home.
1. Keep Your Home Clean
Avoiding build up of dust and pet dander can go a long way to keeping your home fresh and breathable. Set a timer for 10 minutes before you go to bed to tidy up one area of your home in the evenings. Schedule cleaning days where you tackle the tricky areas of the house like the attic or basement. Put on your favorite playlist and get into a cleaning groove. A clean home is a healthy home.
2. Control Humidity Levels
Keeping your humidity levels in an optimal range can help prevent mold from growing. This is a major issue faced by homeowners. You can buy humidity sensors and install dehumidifiers in your home. The recommended level is between 30-50% humidity. Any lower can lead to eczema and respiratory issues because your environment is too arid. On the other hand, high humidity can lead to a damp environment where dust mites and mold spores thrive.
3. Choose Non Toxic and Zero VOC Household Products
The items you bring home are the biggest contributors to your indoor air quality. Take a few extra minutes to check labels. Do your research and don’t believe everything that has a green or organic sticker on it. Don’t forget that harmful VOCs can be sealed by additional coats of paint. Your walls are the largest surface in your home and dictate your air quality.
Frequently Asked Questions About Indoor Air Quality
What is indoor air quality (IAQ)?
Indoor air quality refers to the condition of the air inside and around buildings, including homes, offices, and schools. It is determined by the presence of pollutants such as VOCs, mold spores, dust, pet dander, carbon monoxide, and radon. The EPA consistently finds that indoor air contains higher concentrations of many pollutants than outdoor air.
Why is indoor air quality important?
Poor indoor air quality is a significant health risk because most people spend up to 90% of their time indoors. Exposure to indoor pollutants can cause immediate symptoms like headaches, eye irritation, and worsened asthma, and long-term effects including respiratory disease, immune suppression, and increased cancer risk — particularly in children, older adults, and people with chronic conditions.
What are the most common indoor air pollutants?
The most common indoor air pollutants are: volatile organic compounds (VOCs) from paints, solvents, and furniture; formaldehyde from particle board and manufactured wood products; mold from moisture and humidity; lead and asbestos in pre-1980s homes; radon gas (the second leading cause of lung cancer in the US); and particulates from dust, pet dander, and outdoor air infiltration.
How can I test my home's air quality?
You can use an air quality meter to measure VOC and CO2 levels at home. Look for a meter that measures total volatile organic compounds (TVOC) — some also detect formaldehyde specifically. Visual signs of poor IAQ include condensation on windows, visible mold growth, and excessive dust buildup. Physical symptoms like persistent headaches, fatigue, or worsening allergies can also signal a problem.
How can I improve indoor air quality quickly?
The fastest improvements come from: increasing ventilation by opening windows when outdoor air quality is good; running exhaust fans in kitchens and bathrooms; vacuuming regularly with a HEPA filter; choosing low-VOC or zero-VOC paints and materials for any renovations; reducing humidity to below 50% to prevent mold; and replacing synthetic air fresheners with natural alternatives. For serious concerns, consider an air purifier with a HEPA and activated carbon filter.
