Which of the following factors contributes to Indoor Air Quality (IAQ)?

The factor that significantly contributes to Indoor Air Quality (IAQ) is the building materials and activities within the building. Building materials can release volatile organic compounds (VOCs) and other pollutants into the air, which can affect air quality. Activities such as cooking, cleaning, and the use of appliances can introduce additional contaminants like particulates, fumes, and chemical residues.

Understanding how these materials and activities impact air quality is crucial for maintaining a healthy indoor environment. For instance, newer buildings may have materials that off-gas over time, while renovation activities can disturb dust and mold. Proper ventilation and the choice of low-emission materials can help mitigate these risks, improving overall IAQ.

In contrast, while the age of the building may relate to certain safety codes and conditions, external weather patterns primarily affect outdoor air quality rather than directly contributing to IAQ. Furthermore, while the number of people in an elevator might have a negligible effect on IAQ temporarily, it does not address broader or more substantial factors influencing air quality throughout a building.