Characterizing Local and Regional Contributions to the Aerobiome of the University of California, Irvine Campus

JASMINE OSEI-ENIN, Celia Faiola, University of California, Irvine

     Abstract Number: 487
     Working Group: Aerosol-Ecosystem Interactions

Abstract
Bioaerosols account for approximately thirty percent of atmospheric aerosol loads in the coarse particle size range. The collective composition of bioaerosols that reside in the planetary boundary layer are referred to as the aerobiome. Atmospheric aerosols PM₁₀ and PM_2.5 are regulated by the Environmental Protection Agency due to their negative impacts on human health, but it is unclear how the aerobiome composition could modulate this effect. The aerobiome can lead to positive or negative effects for humans by providing microbes that strengthen the immune system or transmitting pathogens, respectively, depending on the microbial composition. Urban areas with limited plant life have low aerobiome biodiversity, which has been linked to negative consequences for human and environmental health. Microbe contributions from soil, plants, and animals are believed to increase the biodiversity of local aerobiomes, but it remains unclear how proximity to these sources influence the microbial composition of a local aerobiome in an urbanized setting.

In this preliminary study, we compared and contrasted aerobiome composition between four sampling sites located on the University of California, Irvine campus across four seasons. Each sampling location was selected to represent different levels of greenness, types of vegetation, and local versus regional sources. Sampling locations at Aldrich park and San Joaquin Marsh represent high greenness with managed and natural vegetation, respectively, while collection at a parking lot was considered isolated from vegetation. One sampling location was the roof of Croul Hall, 121.5 meters above ground level, to observe the regional aerobiome of the campus. Using gravitational settling methods, bioaerosol samples were collected at 1.0 and 2.0 meter heights to capture the vertical range of air most experienced by children and adults because aerobiome composition exhibits steep vertical gradients near Earth’s surface. Each aerobiome will be characterized from bioaerosol samples using a Zymobiomics micro kit and sequenced via Illumina 16s rRNA and ITS protocols for bacterial and fungi communities, respectively. With these findings, we can better understand the role of aerobiomes in the urban setting.