(Last Updated On: March 24, 2023)

Why is the Air Inside Your Home More Toxic Than Outside? 

By Becky Dotson

5 min read

Thoughts about air pollution don’t generally conjure up images of your living room. But the Environmental Protection Agency (EPA) says indoor air quality can be two to five times worse than the air outside. Couple that with research that shows we spend about 90 percent of our time indoors, and the result can be breathing in a lot of dirty air.

Air purifier on wooden floor in comfortable home. Fresh air and healthy life.

What Causes Indoor Air Pollution?

Just like pollution outside, there’s no one single source of air pollution inside our homes. It’s a mixture of things inside that release gasses and airborne particles combining to create what ends up being unhealthy air.

The EPA says the following list is the main sources of poor indoor air quality:

  •         Central Heating and Cooling Systems
  •         Coal
  •         Deteriorating Building Materials
  •         Furniture Made of Certain Pressed Wood Products
  •         Gas
  •         Household Cleaning Products
  •         Insulation Containing Asbestos
  •         Kerosene
  •         Oil
  •         Outdoor Pollution Flowing Inside
  •         Personal Care Products
  •         Pesticides
  •         Products Used for Maintenance of Appliances and Vehicles
  •         Radon
  •         Tobacco Products
  •         Wet or Damp Carpet
  •         Wood

There are several reasons why these items cause poor indoor air quality. One of the main reasons is ventilation. The good news is, homes these days are built to be more energy efficient. Everything from the windows to the caulking around them is designed to make it easier to moderate the temperature inside. The bad news is that tight construction can also trap bad air and keep it from escaping – causing it instead to linger and build up inside your home. Running fans regularly and opening windows when you can will help increase ventilation in your home.

Building materials, cleaning solutions and hazardous chemicals are also a big cause of bad indoor air. If you live in a home built before 1978, your paint may contain lead. Some older building materials like drywall, insulation or tile products may contain asbestos. Disturbing these through remodels can send dangerous chemicals into the air. Newer building materials like plywood or pressed wood are made with chemicals that give off gasses and odors as they age.

We store adhesives, carpets, chemicals, cleaning products, paints, polishes, and solvents in our homes and attached garages. As they age they can emit toxic chemicals like benzene and formaldehyde which are bad for the air and for breathing. It’s best to store things like these outside in a shed or detached garage.

10 Ways You Improve the Air Quality in Your Home

There are some other, simple things you can do and changes you can make to help improve the air quality in your home.

Check and Change Your Filters

Your HVAC system can be a contributor to poor indoor air quality if you don’t have the ducts professionally cleaned. The filters used for your HVAC system will primarily only filter out larger particles and will do so only when the system is running. Since your HVAC system circulates air in your home, leaving a dirty filter can force dirty air inside when the system is on. It’s a good idea to buy lower-rated filters. The high-grade HVAC filters can choke off your system and shorten the life of your unit.

It’s easy to forget when to change the filters for your HVAC system – so you can write the date you change them on the filter with a pen, put a reminder in your phone or mark it down on the calendar to help you remember. In between filter changes, check it once a month. There’s a chance it may be dirtier than you expect and might need to be changed sooner.

Don’t Smoke Indoors

If you or a loved one is a smoker, then go outside to do it. And don’t let anyone else smoke inside your home. Smoke from tobacco products is unhealthy to breathe and can cause serious health problems in the short and long-term.

Test Your Home for Radon

Radon is a dangerous, invisible gas that’s produced naturally from the breakdown of uranium in soil and rocks. Sometimes, it can seep into homes that are built on dirt with natural uranium deposits. It’s believed to be a key cause of lung cancer, since it exposes someone to small amounts of radiation when it’s breathed in. It’s important to have your home tested for radon since you can’t see or smell it. You can call a professional or buy a do-it-yourself kit at a hardware store to test your home for it.

Keep the Humidity Level Low

Doing your best to keep the humidity level in your home low – below 50 percent is best. Humidity creates moisture and moisture creates the perfect environment for mold to grow. Mold spores can cause significant breathing issues. Standing water also promotes mold growth, so be sure and fix any leaks or drips you may have in pipes and faucets inside and under your house as soon as you discover them.

Don’t Burn Wood

A wood-burning fireplace is really cozy on a cold night, but burning wood inside causes pollution by sending smoke and unhealthy soot into the air.

Open the Windows

Open your windows from time to time to let fresh air inside. It’s a good idea, even during the winter months. Make sure to check the air quality outside before you do it. You don’t want to choose a day when outdoor air quality is bad – forcing more unhealthy air inside.

Put Things Away

It’s easy to leave food or trash out and think, ‘I’ll get to that later.’ But it’s best to put food away and throw away and cover up your trash. Food and trash create pests like mice and cockroaches. And you may not realize it, but these types of pests leave dander and urine behind that contribute to the pollution in your home.

Keep Things in Working Order

Make sure your stove, furnace, space heater or any other gas-powered piece of equipment is in good working order. Have your HVAC system serviced every spring and fall. The central heat and air system can develop leaks and build up carbon monoxide in your home if it isn’t well-maintained.

Keep Your House Clean

Regular dusting and vacuuming will help keep the air in your home clean. The dust, dirt and pet dander inside your home circulate in the air – making it easier for you to breathe them in. Weekly cleaning and vacuuming won’t get rid of it all, but it will help cut down on the amount that’s inside. And don’t forget to dust off the blades on your ceiling fans. Using them to help circulate air doesn’t do any good if they’re covered in dust.

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Invest in an Air Purifier

Air purifiers are made to purify the air. Most of them come equipped with a HEPA filter – which is a highly effective tool at capturing the smallest of pollutants in the air. HEPA filters can capture up to 99.97 percent of the irritants floating around, sending clean air back out. Air purifiers can greatly reduce the amount of particle pollution inside your home and are one of the best ways to ensure you and your family are breathing in healthy air. Here are a couple of our top recommendations:

Alen BreatheSmart 75i True HEPA Air Purifier

The BreatheSmart 75i cleans up to 1300 square feet every 30 minutes. It works with a HEPA filter and has a particle sensor that can let you know the air quality in real time and adjust accordingly. The unit has five fan speeds and is whisper quiet. It’s also Wi-Fi-enabled and can be run through the app. It sells for between $700 and $800 and has a lifetime warranty.

Blueair Classic 605

This unit covers up to 775 square feet and can purify the air in the room up to five times an hour. It’s Wi-Fi-enabled, has a HEPA and activated carbon filter and is equipped with a child safety lock. The Blueair Classic 605 has three fan speeds and wheels to move it around. It costs between $300 and $400 and has a one-year warranty.


We spend a lot of time at home – because as the saying tells us – there’s no place like it. It can be a source of comfort and peace, but you don’t want it to be a source of polluted air. Taking some simple steps will help clean up the particles that are floating around, and ensure your home is a healthier place to be.


Top Pick

BreatheSmart 75i
Air Purifier
$749 Buy Now

Top Pick

Blueair Classic 605
Air Purifier Buy Now