Microbiomes of built environments: 2011 symposium highlights and workgroup recommendations

The air we breathe inside buildings dominates overall inhalation exposure to most air pollutants, whether of indoor or outdoor origin. The same is true for our exposure to microorganisms. Over the past three decades much has been learned about chemicals (in gas and particle phases) in building air, including typical levels, sources, fate, and control. Far less has been learned about the types, sources, and fate of microorganisms in buildings, and about how building design, and operation and maintenance affect microorganisms in buildings. Knowledge creation has been constrained by historical reliance on culture-based methods that can yield only partial or biased assessments of microbial community structure, sometimes dramatically underestimating uncultivable organisms, and failing to detect fragments of organisms that may themselves influence human health. However, in the past several years, advances in culture-independent analytical methods have significantly increased knowledge related to microbial communities and diversity in buildings. We are positioned to make even stronger gains in the coming years.