PhD Proposal Defense: Haley Plaas (ESE – Paerl), Understanding the Impacts of Harmful Cyanobacteria Blooms on Air Quality

The environmental health of aquatic ecosystems is threatened by the global proliferation of cyanobacterial harmful algal blooms (CHABs) in key drinking water and recreational water resources. In recent decades, the occurrence of CHABs has increased spatiotemporally due to climate change and eutrophication, increasing associated public health impacts. In addition to the impacts that CHABs and their biochemical compounds have on water quality, recent work has demonstrated that they also influence air quality, posing unexplored respiratory health issues. Aquatic cyanobacteria and several of their compounds occur in respirable aerosol across diverse ecosystems, but the environmental conditions which promote the aerosolization of cyanobacterial cells, their toxins, and other metabolites are understudied. Additionally, the chemical composition and potential health effects of secondary organic aerosol (SOA) derived from freshwater CHABs have yet to be explored. As CHABs expand across North Carolina (NC) and beyond, it is essential to gain a better understanding of the composition and fate of aerosol emitted by and derived from CHABs. Accordingly, the key aims of this dissertation research are to: 1) identify key environmental drivers of cyanobacterial cell aerosolization in the airshed of the Chowan River-Albemarle Sound estuary, NC, 2) examine SOA formation from cyanobacterial volatile compounds and identify molecular tracers of cyanobacterial-derived SOA, 3) quantify cyanotoxins in health-relevant aerosol size fractions in the airshed of the San Francisco Bay Delta estuary, California, and 4) identify associations between indicators of CHABs and aerosol concentrations in the airshed of the Chowan River-Albemarle Sound Estuary, NC. Results obtained from this ongoing dissertation effort will yield new information regarding the environmental drivers of CHAB cell and cyanotoxin aerosolization, as well novel tracers of cyanobacterial-derived SOA in the air. Findings will inform the emergent public health risks potentially associated with CHABs and aquatic aerosol.