Indoor air quality and wellness

Poor indoor air quality can restrict occupant productivity and comfort and cause sickness.

Possible health effects associated with indoor air pollutants include irritation of the eyes, nose, and throat; headaches, dizziness and fatigue; and respiratory diseases, heart disease and cancer.

Some common indoor air pollutants can negatively impact health. Radon is a carcinogen and can cause lung cancer. Exposure to elevated carbon monoxide levels in indoor settings can be lethal since it is toxic. Legionnaires' disease, a type of pneumonia caused by exposure to the Legionella bacterium, have been linked to buildings with poorly maintained air-conditioning or heating systems.

Several indoor air pollutants—dust mites, mold, pet dander, tobacco smoke, cockroach allergens, particulate matter and others—are asthma triggers.

Sick building syndrome occurs when building occupants experience similar symptoms after entering a particular building but then symptoms dissipate after they leave the building. Increasingly, this is being attributed to a building’s indoor air quality or composition.

Degrading materials such as asbestos, as well as newer building materials that off-gas chemicals, including pressed wood products, are potential sources of indoor air pollutants. Combustion sources, like cooking appliances and fireplaces, and cleaning products, paints, and insecticides are also sources of pollutants. Outdoor air pollutants can enter buildings through open doors or windows, ventilation systems and cracks in building foundations.

Infiltration, natural ventilation and mechanical ventilation all contribute to a building’s air exchange rate with the outdoors, which impacts concentrations of indoor air pollutants.

More extreme weather prompts occupant behavior such as opening or closing windows and operating air conditioners, humidifiers, or heaters; it also can increase the potential for indoor moisture and mold growth if not controlled by sufficient ventilation or air conditioning.

How WRBs can improve IAQ

IAQ conditions depend on a building’s design, construction, durability, and maintenance. If incorrectly installed or with mediocre materials, a WRB can lower the IAQ. That’s why contractors should inspect buildings that are under construction for inconsistencies that could possibly allow in water or other outdoor elements. The building should be kept at a suitable temperature and low humidity (between 30–50%) to prevent mold from forming.

The properly installed WRB can improve a building’s indoor air quality by reducing air leakage, which helps the HVAC system maintain comfortable temperatures; by reducing mold formation (through preventing water into the wall assembly and allowing water vapor inside to evaporate); and by reducing external contaminants entering the building.

Learning the important aspects of proper air quality management helps occupants to maintain a comfortable and healthy environment.