Continental-scale distributions of dust-associated bacteria and fungi

Albert Barberán, Joshua Ladau, Jonathan W. Leff, Katherine S. Pollard, Holly L. Menninger, Robert R. Dunn, Noah Fierer

Research output: Contribution to journalArticlepeer-review

317 Scopus citations


It has been known for centuries that microorganisms are ubiquitous in the atmosphere, where they are capable of long-distance dispersal. Likewise, it is well-established that these airborne bacteria and fungi can have myriad effects on human health, as well as the health of plants and livestock. However, we have a limited understanding of how these airborne communities vary across different geographic regions or the factors that structure the geographic patterns of near-surface microbes across large spatial scales. We collected dust samples from the external surfaces of ∼1,200 households located across the United States to understand the continental-scale distributions of bacteria and fungi in the near-surface atmosphere. The microbial communities were highly variable in composition across the United States, but the geographic patterns could be explained by climatic and soil variables, with coastal regions of the United States sharing similar airborne microbial communities. Although people living in more urbanized areas were not found to be exposed to distinct outdoor air microbial communities compared with those living in more rural areas, our results do suggest that urbanization leads to homogenization of the airborne microbiota, with more urban communities exhibiting less continental-scale geographic variability than more rural areas. These results provide our first insight into the continen-tal- scale distributions of airborne microbes, which is information that could be used to identify likely associations between microbial exposures in outdoor air and incidences of disease in crops, livestock, and humans.

Original languageEnglish (US)
Pages (from-to)5756-5761
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number18
StatePublished - May 5 2015
Externally publishedYes


  • Aerobiology
  • Allergens
  • Microbial dispersal
  • Microbial ecology
  • Urbanization

ASJC Scopus subject areas

  • General

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