Atmospheric Chemistry of Bioaerosols

Nevada System Of Higher Education, Desert Research Institute, Reno NV

Investigators

Abstract

This project is focused on characterizing biological aerosol particles or bioaerosols (e.g. fungi, bacteria and pollen) in the atmosphere. Bioaerosols affect the physical and chemical properties of atmospheric aerosols and play a crucial role in various climate-relevant atmospheric processes, such as the formation of cloud and ice nuclei. This study will improve understanding of the atmospheric chemistry of bioaerosols as well as yield insights on the parameterization of bioaerosols in regional and global climate models. The study will address the following questions: (1) What is the chemical composition of atmospherically-relevant biological species (fungi, bacteria and pollen)? (2) How do bioaerosols affect atmospheric aerosol mass? (3) How do chemical properties of bioaerosols change as they age in the atmosphere? The analyses will determine chemical composition and changes due to photo-chemical aging using an oxidation flow reactor. Collected ambient bioaerosol samples will be analyzed for biological constituents using high-resolution microscopy and DNA sequence-based techniques, while organic compounds will be quantitatively analyzed using analytical techniques to identify tracer compounds representing primary and oxidized bioaerosol compounds. Project results will help: (i) identify organic tracers specific for bioaerosol genera, (ii) determine the contribution of bioaerosols as well as primary and aged organic compounds to atmospheric organic molecular composition, and (iii) obtain source profiles for bioaerosols to be used in Chemical Mass Balance (CMB) receptor modeling. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.