Understanding Indoor Air Quality: 11 Terms You Should Know

Understanding indoor air quality (IAQ) involves familiarizing yourself with key terms that describe the various components, pollutants, and factors that influence the cleanliness of the air we breathe. Here are 11 essential terms you need to know:


Air Quality Monitoring: The process of collecting and analyzing data on pollutants present in the air. Monitoring provides information about current air quality and trends over time.

Indoor Air Quality (IAQ) Assessment: The evaluation of indoor air to determine the presence of pollutants inside the facility, identify potential sources of contamination and define remediation actions. The final goal is to develop a long-term strategy to maintain a safe and healthy environment for all occupants.

Particulate Matter (PM): Tiny airborne particles suspended in the air, categorized by size. PM2.5 refers to particles with a diameter of 2.5 micrometers or smaller, while PM10 refers to particles with a diameter of 10 micrometers or smaller. For comparison, consider that a human hair has an approximate diameter of 100 micrometers. It would therefore take about 10 PM10 particles or 40 PM2.5 particles to completely surround a hair. PM can include dust, pollen, smoke, and other  pollutants. Read more in this blog post.

Carbon Dioxide (CO2): A colorless, odorless gas produced by human respiration and combustion processes. Elevated indoor CO2 levels can cause headache, dizziness, nausea and other symptoms [1].

Volatile Organic Compounds (VOCs): Organic chemicals that can easily vaporize into the air at room temperature. VOCs are emitted from various sources, including vehicle exhaust, industrial processes, and household products. They can contribute to air pollution and have health implications. More info here.

Humidity: The amount of moisture or water vapor present in the air. Maintaining appropriate humidity levels is essential for comfort and health.

Relative Humidity (RH): The amount of moisture in the air compared to the maximum amount the air can hold at a given temperature. RH is expressed as a percentage.

Air Quality Index (AQI): A standardized system that provides information about the quality of the air in a specific area, usually based on concentrations of major air pollutants. The AQI categorizes air quality into different levels, such as "Good," "Moderate," "Unhealthy," and more, indicating the potential health impacts.

Ventilation: The intentional exchange of indoor and outdoor air to maintain good indoor air quality. Proper ventilation helps dilute indoor pollutants.

HVAC (Heating, Ventilation, and Air Conditioning): Systems that control temperature, humidity, and ventilation in buildings. Properly maintained HVAC systems play a key role in maintaining IAQ.

Sick Building Syndrome (SBS): A term used to describe a range of symptoms experienced by building occupants, often attributed to poor IAQ. Symptoms may include headaches, fatigue, and respiratory issues.

Having gained familiarity with essential terminology, you are now prepared to embark on your journey in the realm of Indoor Air Quality (IAQ).

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[1] https://www.health.state.mn.us/communities/environment/air/toxins/co2.html#:~:text=Occupants%20may%20experience%20health%20effects,dizziness%2C%20nausea%20and%20other%20symptoms.