Week 12 - Materials

Whilst adequate ventilation can dilute or remove contaminants, it can also provide a source of contamination if poorly maintained (e.g. dust or mold spores).  Designing a watertight building which does not contain plumbing leaks can help to prevent mold formation.  However good ventilation is an essential feature of houses situated in areas with high radon emissions (US EPA).  Radon is a gas that occurs naturally from the breakdown—or the radioactive decay—of uranium. Exposure can occur through breathing outdoor air, in buildings and homes, and by eating or drinking (ingestion). Radon gas can seep through cracks in buildings and expose people to the radiation, which can lead to severe health problems.  It is the second leading cause of lung cancer in the United States, estimated to be responsible for more than 20,000 lung cancer deaths each year (Centers for disease control and prevention, 2010).

Prior to building, an important factor in providing optimal indoor air quality is the most effective positioning of the property.   Amongst other things, it is important to consider:

• active soil depressurisation and sealing of vapour intrusion routes to avoid radan contaminiation.
• Positioning buildings away from strong electromagnetic fields
• Position building intakes away and upwind from pollution sources (e.g motorways)