Cooperative Institute for Research in Environmental Sciences

Noah Fierer

Research Interests

Microbial ecology. Terrestrial ecosystem ecology. Microbial biogeography. Impact of global change factors on microbial communities and processes.

Current Research: A microbial perspective on air quality

Microbes are ubiquitous and abundant in the atmosphere. There are typically millions of bacterial and fungal cells per cubic meter of air, and we inhale these microbes every time we step outside. Although most of these microbes are harmless, some can cause disease in livestock, plants, and humans. For the 10 percent of the U.S. population who suffers from asthma, airborne microbes are particularly important given that they are common triggers of allergies and allergenic asthma.

Despite the well-recognized importance of airborne microbes, the microbial diversity found in the near-surface atmosphere remains poorly studied. We have a limited understanding of the spatial variability in airborne bacterial and fungal communities and what factors influence this variability. In particular, we do not know how climatic conditions, surrounding land-use types, and proximity to point sources influence microbial air quality.

To address these knowledge gaps, my group has been using recent advances in high-throughput DNA sequencing to describe bacterial and fungal diversity in dust samples collected outside 1,500 homes located throughout the United States. These samples were collected as part of a unique citizen-science project (http://homes.yourwildlife. org/) that offers an opportunity for people across the United States to participate in the scientific process. This broad-scale survey has not only allowed us to build the first maps of airborne bacterial and fungal diversity across the United States, but we also have been able to quantify how environmental conditions outside the home influence the relative abundances of bacteria and fungi found in the atmosphere.

For example, we have shown that fungal diversity varies in a predictable manner across the U.S. and that we can use information on the hundreds of fungal taxa found in individual dust samples to identify the geographic origin of that sample. Likewise, we have shown how proximity to point sources of bacteria (including livestock enclosures) can be determined by analyzing the types of bacteria found in dust samples. Current work is focused on understanding the distributions of specific microbial pathogens and allergens so we can begin to predict how climate change or land-use change may alter the relative abundances of these taxa in the near-surface atmosphere.

 

Publications

Click here for a complete list of published works »