Aerosolized Harmful Algal Blooms: Distinct Toxins and Congeners Quantified in the Atmosphere

Jia Shi, Nicole Olson, Johnna Birbeck, Rebecca Parham, Jin Pan, Nicholas Peraino, Andrew Holen, Isabel Ledsky, Stephen Jacquemin, Linsey Marr, David Schmale, Judy Westrick, ANDREW AULT, University of Michigan

     Abstract Number: 583
     Working Group: Aerosol-Ecosystem Interactions

Abstract
Cyanobacterial harmful algal blooms (cHABs) have the potential to adversely affect public health through the production of toxins, such as microcystins, which consist of numerous molecularly-distinct congeners. cHAB toxins have been observed in the atmosphere after emission from freshwater lakes, but little is known about the health effects of inhaling these toxins and factors contributing to their aerosolization. This word discusses quantification of microcystin congener and other toxin concentrations in water and aerosol samples collected around Grand Lake St. Marys (GLSM), Ohio. Concentrations in water ranged from 13-110 µg/L, with microcystins dominated by the D-Asp3-MC-RR congener. In particulate matter ≤2.5 µm (PM2.5), microcystin concentrations up to 156 pg/m^3 were detected; the microcystins were comprised primarily of D-Asp3-MC-RR, with additional congeners (D-Asp3-MC-HtyR and D-Asp3-MC-LR) observed during periods of elevated wind speeds. The PM size fraction containing the highest MC concentrations ranged from 0.44 to 2.5 µm. Aerosolized bacterial 16S rDNA using qPCR, were observed in samples (≤3 µm) with concentrations up to 9.4×10^4 gc/m^3. Concentrations of aerosolized microcystins varied even when concentrations in water were relatively constant, demonstrating the importance of meteorological conditions (wind speed and direction) and aerosol generation mechanism(s) (wave breaking, spillway, aeration systems) when evaluating inhalation exposure to microcystins and other toxins, along with their subsequent impacts on human health.