IAQ FAQ

  1. What is Indoor Air Quality (IAQ)?
  2. What causes indoor air problems?
  3. What problems are caused by poor IAQ?
  4. Where does radon come from?
  5. Should I test the soil for radon before building?
  6. What about schools, mold, and indoor air quality?
  7. What are Volatile Organic Compounds (VOCs)?

What is Indoor Air Quality (IAQ)?

Indoor Air Quality (IAQ is a term used to characterize health and comfort-related conditions inside a building designed for human occupancy. Relevant factors include air temperature, relative humidity levels, airborne and surface contaminant concentrations, lighting, and noise. A building\’s IAQ is typically considered acceptable if occupants are not exposed to harmful contaminant concentrations and a large majority of the occupants are satisfied with Indoor Air conditions. Occupants\’ perceptions of IAQ for a building, or a space within a building, can vary because of individual variations in temperature/humidity level preferences and sensitivities to chemical and biological contaminants. Perceptions can also be affected by issues that are not associated with Indoor Air conditions, such as unrelated health problems and psychosocial factors (work-related or personal stress).

What causes indoor air problems?

Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the building. High temperature and humidity levels can also increase concentrations of some pollutants.

What problems are caused by poor IAQ?

With poor IAQ, the same air born particles are circulated continuously throughout the building. This can lead to an unhealthy and uncomfortable indoor environment and put you and your employees’ health at risk. Resulting problems can range from recurring flus and aggravated allergies to persistent coughs, headaches, and poor concentration. Another common problem that can result from poor IAQ is humidity. Trapped moisture can, over time, lead to serious mold and/or bacteria concerns in a buildling. Recently, the American Society of Heating, Refrigeration and Air Conditioning reported that 90% of all building failures are related to moisture.

Where does radon come from?

Radon-222 is the decay product of radium-226. Radon-222 and its parent, radium-226, are part of the long decay chain for uranium-238. Since uranium is essentially ubiquitous (being or seeming to be everywhere at the same time) in the earth\’s crust, radium-226 and radon-222 are present in almost all rock and all soil and water.The amount of radon in the soil depends on soil chemistry, which varies from one house to the next. Radon levels in the soil range from a few hundred to several thousands of pCi/L (pico Curries per Liter). The amount of radon that escapes from the soil to enter the house depends on the weather, soil porosity, soil moisture, and the suction within the building.

Should I test the soil for radon before building?

Soil testing for radon is not recommended for determining whether a house should be built radon-resistant. Although soil testing can be done, it cannot rule out the possibility that radon could be a problem in the house you build on a lot. Even if soil testing reveals low levels of radon gas in the soil, the amount of radon that may enter the finished house cannot be accurately predicted because one cannot predict the impact that the site preparation will have on introducing new radon pathways or the extent to which a vacuum will be produced by the house.  Furthermore, the cost of a single soil test for radon ranges from $70 to $150, and at least 4 to 8 tests could be required to accurately characterize the radon in the soil at a single building site.  Therefore, the cost to perform the soil testing is very high when compared with installing the passive radon system in high radon potential areas (see the EPA Map of Radon Zones at www.epa.gov/radon/zonemap.html).

What about schools, mold, and indoor air quality?

Moisture problems in school buildings can be caused by a variety of conditions, including roof and plumbing leaks, condensation, and excess humidity. Some moisture problems in schools have been linked to changes in building construction practices during the past twenty to thirty years. These changes have resulted in more tightly sealed buildings that may not allow moisture to escape easily. Moisture problems in schools are also associated with delayed maintenance or insufficient maintenance, due to budget and other constraints. Temporary structures in schools, such as trailers and portable classrooms, have frequently been associated with moisture and mold problems.

What are Volatile Organic Compounds (VOCs)?

Volatile organic compounds are compounds that have a high vapor pressure and low water solubility. Many VOCs are human-made chemicals that are used and produced in the manufacture of paints, pharmaceuticals, and refrigerants. VOCs typically are industrial solvents, such as trichloroethylene; fuel oxygenates, such as methyl tert-butyl ether (MTBE); or by-products produced by chlorination in water treatment, such as chloroform. VOCs are often components of petroleum fuels, hydraulic fluids, paint thinners, and dry cleaning agents. VOCs are common ground-water contaminants.