How Clean Is Your Indoor Air?


What to Do About Air Pollution in Your Home

A recent 2018 report on climate change indicates that air quality is becoming an increased threat to human health. While the quality of outdoor air has been the focus of climate change discussion, indoor air quality is equally significant

According to research by the U.S. Environmental Protection Agency (EPA), we spend a shocking 90 percent of our lives in indoor environments such as homes, schools, workplaces, gyms, and transportation vehicles. (1)

The extensive amount of time we spend inside buildings exposes us to a variety of indoor air pollutants, some of which are more harmful than outdoor air pollutants!

Read on to learn about the types of indoor air pollutants you may encounter in your home and workplace, how these pollutants impact health, and what you can do to clean up the air in your living and work environments.

The 11 Types of Indoor Air Pollution

According to the recently-published Fourth National Climate Assessment, more than 100 million people in the United States live in communities where air pollution exceeds health-based air quality standards. (2)

In addition, it is estimated that nearly 2.6 million people globally die per year from illnesses attributable to indoor air pollution. Together, these two sources of pollution are a looming threat to our health with significant long-term, even transgenerational, consequences.

Indoor air pollution represents the sum total of outdoor air pollutants, which easily enter indoor environments through windows and air ventilation systems, and pollutants originating indoors. Some of the most common indoor air pollutants include asbestos, gases, biological particles (bacteria, fungi, pollen, and animal dander), particulate matter, and volatile organic compounds (VOCs).


What is it? Asbestos is a type of mineral fiber that naturally occurs in rock and soil.

Why is it in our air? The strength and heat resistance of asbestos fibers was discovered in the early 20th century, leading to the enthusiastic incorporation of asbestos into numerous building materials as an insulator and fire retardant.

Is it harmful? While scientific research first linked asbestos exposure to mesothelioma, a type of lung tumor, in the 1930s, it wasn’t until the 1970s that the U.S. government passed legislation to limit asbestos use in construction and manufacturing. However, contrary to what many people believe, asbestos is not banned in the U.S!

While more than 50 other countries have banned toxic asbestos, including the U.K., Australia, Canada, and all 28 countries in the European Union, the U.S. continues to allow these substances to be used in hundreds of consumer products, including gaskets, roofing materials, and fireproofing materials. (3)

Asbestos exposure is an established cause of mesothelioma, lung cancer, and other chronic, debilitating respiratory conditions. Remediation by a highly-qualified professional is the only recommended strategy for eliminating asbestos in living and workspaces; DIY attempts to remove asbestos can significantly worsen the problem by spreading the asbestos, further contaminating the indoor environment.

Biological Pollutants

What are they? The term “biological pollutants” refers to indoor air pollutants that are biological in nature, such as mold and mycotoxins, bacteria, viruses, animal dander, cat saliva, dust mites, cockroaches, and pollen.

Why are they in our air? Standing water and water-damaged materials are particularly hospitable substrates for the growth and proliferation of mold, bacteria, viruses, and their toxic byproducts.

Are they harmful? Shocking statistics from the U.S. EPA indicate that 85 percent of buildings in the U.S. have past water damage and 45 percent have current water leaks; these figures suggest that our indoor spaces are quite the breeding ground for indoor biological pollutants! (4)

Carbon Monoxide

What is it? Carbon monoxide is an odorless, colorless, deadly gas.

Why is it in our air? Carbon monoxide is produced by a variety of indoor sources, including gas water heaters, gas stoves, wood stoves, fireplaces, generators, gas space heaters, and car exhaust from attached garages. (5)

Is it harmful? Because it is impossible to see, taste, or smell, carbon monoxide can cause adverse health effects (at low levels) or kill you (at high levels) before you are even aware that it is in your home. Properly maintaining gas appliances, opening flues when fireplaces are in use, not idling your car in the garage, and hiring a trained professional to inspect, clean, and regularly tune up your central heating system can reduce the potential for exposure to carbon monoxide.

Nitrogen Dioxide

What is it? Nitrogen dioxide is a highly reactive gas.

Why is it in our air? Nitrogen dioxide is produced indoors by unvented combustion appliances (gas stoves and wood stoves), welding, tobacco smoke, and kerosene heaters.

Is it harmful? This gas is linked to respiratory problems and other issues. Properly maintaining and venting gas appliances, regularly maintaining and cleaning your central heating system, and not idling your car in the garage can reduce your exposure to nitrogen dioxide.


What is it? Radon is another colorless, odorless gas.

Why is it in our air? It results from the radioactive decay of radium in soil. It has a high density that causes it to sink in air; as a result, it is often found in the basements of homes.

Is it harmful? Exposure to radon is also linked to respiratory issues and lung cancer. Sealing basements to prevent gas exchange with the surrounding soil can reduce the potential for radon pollution.


What is it? Formaldehyde is a colorless gas with an acrid odor.

Why is it in our air? It is emitted by many indoor sources, including plywood, particleboard, pressed/composite wood products, permanent press fabrics, and combustion appliances (6).

Is it harmful? Formaldehyde is highly irritating to the eyes, nose, and lungs as well as cytotoxic and carcinogenic.


What is it? Lead is a toxic heavy metal.

Why is it in our air? Lead was historically used in paint, gasoline, water pipes, and many other consumer products. If your home was built before 1978, there’s a good chance it contains lead-based paint, which creates air-polluting lead dust. (7)

Is it harmful? Heavy metals in our bodies are linked to many health issues. Unfortunately, merely painting over lead-based paint with conventional paint does not eliminate the problem; typically, remediation by a professional is required to manage the existing lead and prevent further contamination of your living space. High levels of airborne lead can also originate from lead-contaminated soil tracked indoors.

You can reduce airborne lead levels in your home by remediating existing lead-painted surfaces and by removing your shoes when you head indoors.


What is it? Pesticides, including Roundup, are simply chemicals used to kill off unwanted plant growth.

Why is it in our air? According to recent statistics, a whopping 75 percent of U.S. households used at least one pesticide product indoors in the past year. (8) In addition, farm fields, public parks, and soccer fields are all subject to pesticide spraying, so whether you live in a rural or suburban area, it is likely that your shoes are in regular contact with pesticide-contaminated soil and dust.

Is it harmful? Yes! Since these chemicals are meant to kill plant growth, we don’t want them in our bodies. (To learn more about pesticides, check out my blog here.)

To reduce your exposure to pesticides, avoid using them in your home and make your living space a “no shoes” zone to minimize the opportunity for pesticide-contaminated soil or dust to enter your home.

Secondhand Smoke and E-cigarettes

It’s abundantly clear that secondhand smoke represents a serious form of indoor air pollution. However, recent research indicates that e-cigarettes, widely promoted as “less harmful” than cigarettes, produce equally harmful indoor air pollution (9).

Volatile Organic Compounds (VOCs)

What are they? Volatile organic compounds are substances emitted as gases from certain liquids and solids.

Why are they in our air? Indoor volatile organic compounds are released by paint, varnishes, cleaning and disinfecting agents, aerosol sprays, paraffin candles, furniture, and automotive products.

Is it harmful? VOCs have been linked to various issues, including respiratory, liver, kidney, and nervious system problems.

Indoor Particulate Matter

What is it? Particulate matter (PM) is a mixture of solid and liquid particles.

Why is it in our air? PM is released into the air during the combustion of wood, coal, gasoline, and diesel as well as from natural sources such as road dust and wild fires.

Is it harmful? Surprisingly, indoor PM levels frequently exceed those of PM found in outdoor environments, making indoor PM pollution a significant threat to human health. (10) The most common sources of indoor particulate matter include wood and gas stoves, heaters, fireplaces, candles, cooking, and cigarette smoke.

The Health Effects of Indoor Air Pollution

The health effects of indoor air pollutants may be experienced shortly after exposure or, possibly, years later. Regardless, indoor air pollution has a host of adverse effects on our health. Leaving indoor air pollution unaddressed is arguably equally as harmful to our health as eating an unhealthy diet or skimping on sleep.

Respiratory Diseases

Air pollutants of all types have demonstrated adverse effects on the respiratory system.

Indoor mold and mycotoxins increase the risk of asthma-like symptoms, respiratory infections, and allergic rhinitis.

Nitrogen dioxide, tobacco smoke, formaldehyde, VOCs, and particulate matter are associated with asthma, bronchitis, and COPD. (11, 12)

Of course, asbestos is notorious for its harmful effects on the respiratory system – it is firmly established that they cause pulmonary fibrosis (scar tissue accumulation in the lungs), lung cancer, shortness of breath, cough, and chest pain.

Heart Disease

Air pollution promotes the development of atherosclerosis, the buildup of fats, cholesterol, and pro-inflammatory molecules in artery walls that is a major driver of cardiovascular disease. (13)

Gaseous pollutants (carbon monoxide, nitrogen dioxide) appear to promote atherosclerosis by crossing the airway epithelium, entering blood vessels, and instigating the production of free radicals and pro-inflammatory cytokines. These inflammatory molecules raise blood pressure, alter the nervous system’s control of heart function, and oxidize circulating cholesterol, causing atherosclerosis.

Autoimmune Disease

Prolonged exposure to air pollution structurally modifies body proteins to create autoantigens, induces an aberrant immune response, and stimulates chronic inflammation; together, these factors may provoke the development of autoimmune disease. (14)

Indeed, asbestos exposure is an established risk factor for autoimmune disease. (15) Occupational exposure to silica dust, pesticides, solvents, and other airborne substances increases the risk of systemic lupus erythematosus, while PM pollution exacerbates type 1 diabetes, rheumatoid arthritis, juvenile idiopathic arthritis, and multiple sclerosis. (16)

If you or someone you love is struggling with autoimmune disease, as so many people are today, then cleaning up your indoor air should be a priority!

Antibiotic-Resistant Bacteria

Alarmingly, indoor air is a significant source of antibiotic-resistant bacteria. Employees in office buildings and students in schools share enclosed spaces with a broad spectrum of microorganisms present on their skin and in their mouths and nasal cavities.

These crowded environments allow for the transfer of microbes from one person to another and for the evolution of dangerous drug-resistant bacteria (17, 18). Furthermore, these microorganisms produce bioaerosols, tiny airborne particles that are biological in nature and have adverse effects on human health.

Brain Function

While air pollution is classically associated with respiratory and cardiovascular disease, emerging research indicates that it also affects the brain. (19) Indoor fine and ultrafine particulate matter from sources such as cooking, scented candles, and cigarette smoke, poses a unique threat to the brain because these tiny particles cross the blood-brain barrier and subsequently induce brain oxidative stress and neuroinflammation.

The inhalation of mold mycotoxins inside water-damaged buildings also triggers brain inflammation, induces apoptosis of brain cells, and alters brain neurotransmitter levels. (20)

The cellular effects of indoor air pollutants on the brain have serious neurocognitive repercussions. Exposure to indoor air pollutants has been found to alter brain development, impair memory and reasoning, and increase the risk of neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases. (21, 22, 23)

Interestingly, the neurocognitive effects of indoor air pollution may adversely affect an individual’s ability to perform his or her job; a recent study found that for each 10-unit increase in outdoor air pollution, a phenomenon that worsens indoor air quality, worker productivity declined by 0.35 percent. (24)

This can really add up on poor air quality days! If you want to optimize your children’s brain health and preserve your own cognitive function, then cleaning up your indoor air is a must.

Children’s Health

Indoor air pollution has particularly detrimental effects on children. Indoor airborne particulate matter and molds increase the risk of childhood allergies while traffic-related air pollution (which can easily carry over indoors) reduces cognitive function and may contribute to ADHD. (25, 26, 27)

Importantly, the types of air pollutants to which a woman is exposed during pregnancy may affect her children’s health down the road; maternal exposure to polycyclic aromatic hydrocarbons, a type of particulate matter, during pregnancy has been found to increase the risk of neurobehavioral problems in offspring. (28)

How to Clean up Your Indoor Air

The first step you should take to clean up your indoor air, whether in your home or workplace, is to eliminate sources of airborne pollutants. Listed here are key strategies for reducing sources of indoor air contaminants:

  • Get your indoor air quality assessed by a home air quality testing company.

  • Work with an indoor air specialist to remediate sources of indoor air pollution, including asbestos, moldy and water-damaged areas, and lead-painted surfaces. Repair existing water leaks to prevent future water damage.

  • Maintain a relative home humidity of 30-50 percent to inhibit the growth of mold and other biological pollutants in your home. A dehumidifier can help you accomplish this. Be sure to empty the water-collecting reservoir of the dehumidifier regularly to prevent mold growth in the machine.

  • Properly maintain, clean, and fine-tune combustion appliances and make sure that all appliances are vented to the outdoors.

  • Regularly replace the filters on central heating and cooling systems.

  • Swap formaldehyde-containing building materials for solid wood, stainless steel, adobe, bricks, and tile. Avoid upholstering your furniture or wearing permanent press fabrics.

  • Use low-VOC paint, varnishes, furniture, and fabrics in your home.

  • Don’t use pesticides in your home or yard.

  • Don’t burn paraffin candles or use aerosol sprays like Pledge or Febreze. Opt for 100 percent beeswax candles scented with essential oils instead.

  • Don’t idle your car in the garage.

  • Regularly clean your home with a HEPA vacuum and keep surfaces free of dust.

  • Install a radon detector.

  • Make your home a “no shoes zone” to limit the tracking of lead or pesticide-containing dust indoors.

  • Prohibit smoking of any sort inside your home.

Once you've taken these steps, you should also consider investing in a high-quality air filter to clean the air in your living space continuously.

The Air Filter We Recommend

I do think an air filter is worth the investment, for all the reasons outlined above! But it can be hard to choose one. I have spent some time reviewing air filter options and I am now planning to purchase a filter from Rabbit Air.

Rabbit Air does a better job than filters you’ll find at Target and the like. It’s also more effective than filters like Everest and Molekule. While these ‘filterless filters’ sound great, because there’s no filter to change, they are just dropping contaminants to the floor. If you don’t capture contaminants in a filter, they will be in your house dust where your baby and your dog will roll in them and your kids will kick them back up. House dust is already laden with toxins, and we don’t need to increase the load!

You can get a discount on your Rabbit Air filter by entering the code ‘ABD1743’ at checkout.

Considering that indoor air quality is worse than ever these days, this is a great investment for your family’s health!

Now, I’d love to hear from you! Do you live or work in a building with air quality issues? What steps have you taken to improve the air quality in your living environment? Let me know in the comments below.


Bridgit Danner, LAc, FDNP, is trained in functional health coaching and has worked with thousands of women over her career since 2004. She is the founder of Women’s Wellness Collaborative llc and