IaQ

Indoor air quality (IAQ) refers to the condition of the air inside and around buildings and structures, including homes, schools, and workplaces. IAQ is influenced by outdoor air quality, indoor sources, ventilation effectiveness, and building design and operation.

Common indoor pollutants include particulate matter (PM2.5 and PM10), volatile organic compounds (VOCs), carbon dioxide (CO2) as a ventilation proxy, radon, humidity-related mold and dampness, and biological contaminants such as bacteria, viruses, and dust mites.

Exposure to poor IAQ can cause eye, nose, and throat irritation; headaches; fatigue; and coughing. Long-term exposure may aggravate asthma and other respiratory or cardiovascular conditions. Children, the elderly, and people with allergies or asthma are especially vulnerable.

IAQ is assessed through measurements of pollutant concentrations, airflow, and comfort indicators. Common metrics include PM2.5, PM10, CO2, VOCs, humidity, and radon. Guidelines and standards are provided by organizations such as the WHO, EPA, and ASHRAE, but practices vary by country and building type.

Mitigation emphasizes source control (reducing emissions from cooking, cleaners, and finishes), ventilation optimization (adequate outdoor air supply and heat recovery where appropriate), and filtration (high-efficiency filters, e.g., MERV 13 or HEPA). Humidity control, moisture management, and regular HVAC maintenance are also important.

Good IAQ supports occupant comfort, health, and productivity, and is balanced with energy efficiency goals in building design and operation. Policy measures, building codes, and corporate practices increasingly integrate IAQ considerations into planning and operations.