According to the U.S. Environmental Protection Agency (EPA), in the last several years, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air, even in the largest and most industrialized cities.1

A definition of indoor air quality:
“Indoor air quality is the air quality within and around buildings and structures.”

There are many factors that can affect indoor air quality in each space.

While the dangers of some of these pollutants (such as radon, lead and water contaminants) are well-documented and relatively easy to test for, the documentation and understanding of other pollutants are still emerging.

According to the U.S. Consumer Products Safety Commission (CPSC), health effects associated with indoor air pollutants include irritation of the eyes, nose and throat; headaches; dizziness; fatigue; respiratory diseases; heart disease; and forms of cancer.2

People who may be exposed to indoor air pollutants for the longest periods of time are often those most susceptible to the effects of indoor air pollution. Such groups include people who are young, elderly or have chronic illness, especially those who have respiratory or cardiovascular disease.3

The American Lung Association has declared that poor indoor air quality can cause or contribute to the development of infections, lung cancer and chronic lung diseases such as asthma and chronic obstructive pulmonary disease (COPD).4

Sources of Indoor Air Pollution

There are many types of indoor air contaminants that result from an abundance of sources. Indoor air pollution does not discriminate. It can be detected in all types and styles of homes—old, new, small, large, urban and rural.

The EPA states that most pollutants affecting indoor air quality come from sources inside buildings, although some originate from the outdoors.5

Indoor Sources:

  • Combustion sources
    including tobacco, wood and coal heating, cooking appliances and fireplaces, can release harmful combustion byproducts such as carbon monoxide, carbon dioxide and particulate matter directly into the indoor environment.
  • Cleaning supplies
    paints, insecticides and other commonly used products introduce many different chemicals, including harmful volatile organic compounds, directly into the indoor air.
  • Building materials
    are potential sources, whether through degrading materials (for example, asbestos fibers released from building insulation) or from new materials (for example, chemical off-gassing from pressed wood products)
  • Mold
    growth can result from high levels of indoor humidity caused by poor construction or rehabilitation, or site design that does not properly manage water, inadequate air exchange or both.
  • Inadequate ventilation
    can contribute to excessive moisture and humidity, and contaminents like mold spores, dust particles or other allergens can be drawn in from the outside by the HVAC system.6

Three Most Commonly Monitored Factors of Indoor Air Quality

Fortunately, the many particles and pollutants that are combined in a household can easily be identified with today’s technologies.

Indoor sources can be categorized into a few different measurements and tested individually. These factors are considered the three most commonly monitored factors of indoor air quality:

1.Particulate matter (PM2.5 and PM10) resulting from pollen, mold spores, allergens, bacteria, settling dust, cement dust, smog, fly ash, oil smoke and more.
These two particulate sizes are typically measured when assessing air quality because these particles are capable of entering the lower respiratory tract and affecting human health. PM10 particles are inhalable coarse particles that are within diameter of about 10 micrometers. They are capable of penetrating to the very deepest parts of the lungs. PM2.5 particles are fine particles that are 2.5 micrometers in diameter and smaller and can cross the blood barrier.7

2. Volatile organic compounds (VOCs) that can result from exhaust fumes, building material off-gases, perfumes, alcohol vapors, off-gases from mold growth and more.

3. Carbon dioxide (CO2) that can be produced by improper ventilation, having excessive people in a confined space, unbalanced HVAC systems, decaying vegetation and more.

What can homeowners do?

Indoor air quality and mold detection are very real, complex, existing issues. Each instance should be looked at independently and thoroughly for specific variables.

Consumers can develop good habits to improve indoor air quality. Dusting and vacuuming regularly, keeping smoke and secondhand smoke out, properly ventilating rooms that have fireplaces, making certain the flue damper is operational, ensuring that the chimney is properly sealed, changing HVAC filters regularly and ensuring that bathrooms have functioning exhaust fans. Becoming habitual in performing these simple steps will improve the air inside a property.

Several comprehensive consumer resources are available through the EPA and the CPSC, and many of these resources are referenced in this article. Consumers can read these resources to educate themselves further on the importance of indoor air quality.