What is Indoor Air Quality?

Indoor Air Quality (IAQ) refers to the quality of the air indoors, whether it’s a home, office building, school, or other types of buildings. The majority of people may not be aware that the quality of the air indoors is just as important as the quality of the air outdoors. Many people are familiar with outdoor pollutants such as carbon emissions and burning fuel, but they’re not aware that indoor air pollutants are much higher than outdoor air pollutants. Here’s a look at what causes indoor air pollution, the effects it has on human health, and how to improve air quality indoors.

Threats to IAQ

Many things can threaten the air quality indoors, especially in your own home. In fact, there are only six major outdoor pollutants, while there are nine major indoor pollutants.

Biological Agents

Mold is an example of a biological agent that can be a threat to IAQ. Mold requires moisture to grow, which is why bathrooms and kitchens are most susceptible to mold growth.

Combustion Byproducts

Carbon monoxide, cigarette smoke, and particulate matter (specifically smoke and soot) are all examples of combustion byproducts.


Lead (which used to be found in paint) interferes with the enzymes inside the cells in the organs. Even a small amount of lead can cause serious health issues— especially in children.

Natural Substances

Even though these substances are “natural” or “naturally occurring”, they’re still considered to be a threat to indoor air quality. An example of one of these substances includes pet dander, but radon and asbestos naturally occur in the environment— the latter of which naturally occurs in rock and soil.

Volatile Organic Compounds

Volatile organic compounds (VOCs) are gasses emitted from both solids and liquids, and they’re usually human-made chemicals. VOCs can be found in a variety of household products, including:

  • Wood preservatives
  • Pesticides
  • Paints/paint strippers
  • Furniture
  • Dry-cleaned clothing
  • Cleaners and disinfectants
  • Aerosol sprays

VOCs are also found in building materials, office equipment, and hobby supplies, such as craft materials and photographic solutions.

Poor IAQ and Human Health

Indoor air pollutants are known to irritate the eyes, nose, and throat, as well as headaches, dizziness, and fatigue. These conditions are usually minor, but indoor air pollutants can also irritate existing conditions and/or cause much more serious conditions.


While indoor air pollutants don’t necessarily cause someone to develop asthma, they do trigger attacks in asthmatics. Byproducts of combustion, biological agents, natural substances, and VOCs are all considered to be asthma triggers.


Radon is a known human carcinogen (causes cancer in humans) and is the number one cause of lung cancer in non-smokers, and the second leading cause of lung cancer overall (after cigarette smoke).

Legionnaires’ Disease

Legionnaires’ disease is a severe form of pneumonia caused by the bacterium legionella. Poorly maintained air conditioning and heating systems can cause this.


Mesothelioma is a type of cancer that forms in the thin layer of tissue that covers the organs, with the lungs being a commonly affected organ. Asbestos exposure is the most common cause of mesothelioma, with industrial employees being at the highest risk of being exposed to asbestos. Fortunately, a mesothelioma lawyer can help these victims get compensation, but unfortunately, mesothelioma is incurable.

How to Improve IAQ

The good news is that it’s not that hard to improve the IAQ of your home. Even though there are a lot of air pollutants that can make their way into your home, there are even more ways to help eliminate them.

Change Your Air Filters

If you have an HVAC (heating, ventilation, air conditioning) system in your home, you should change your air filters regularly. Replacing them once a month ensures that unnecessary allergens aren’t flowing through your home.

Buy Air-Purifying Plants

Just as trees help purify the air outdoors, certain houseplants can purify the air indoors. Examples include:

  • Spider plants
  • Snake plants
  • English ivy
  • Aloe vera

Just keep in mind that certain plants are toxic to pets.

Invest in a Dehumidifier

As mentioned earlier, mold likes to grow in wet and humid places, such as a bathroom. Buying a dehumidifier can remove excess moisture from the air.

Vacuum Regularly/Switch to Hard Flooring

Regularly vacuuming your carpet and rugs reduces the amount of dust and pet dander (if you own pets) inside your home. However, vacuuming doesn’t remove 100% of the allergens from the carpet, so you may want to try hard floorings such as hardwood or laminate.

It’s also important to test your home for radon (especially if you have a basement) and also invest in a carbon monoxide detector. Taking these extra steps can greatly improve your home’s indoor air quality.