Quantifying the Impact of Sargassum Stranding on Bioaerosols and Volatile Sulfur Compounds

SHAHAR TSAMERET, Nohhyeon Kwak, Sofia Hoffman, Isabella Tavarez, Rivka Reiner, Jack Balseiro, Larissa Montas, Helena Solo-Gabriele, Jiayu Li, University of Miami

     Abstract Number: 789
     Working Group: Aerosol-Ecosystem Interactions

Abstract
Sargassum is a genus of marine macroalgae that washes up on the shorelines in large quantities. This phenomenon, known as Sargassum stranding, challenges coastal communities and ecosystems. Previous research has shown the impact of Sargassum on water quality, but its impact on air quality remains unclear. It has been proven that the decomposing of Sargassum releases volatile sulfur compounds such as hydrogen sulfide (H2S), dimethyl sulfide (DMS), and dimethyl disulfide (DMDS), but the quantities that it emits are undetermined. Exposure to VSCs can lead to acute respiratory symptoms, so this is a public health concern. In addition, Sargassumcan act as a breeding ground for marine bacteria, so there is a possibility that bioaerosols from Sargassum stranding will contain significant levels of bacteria, which is another public health concern. We investigated the impacts of Sargassum stranding in South Florida on concentrations of VSCs and bioaerosols. Biosamplers were used to capture bioaerosols on-site at a beach experiencing Sargassum stranding, and UV fluorescence analyzers were implemented to detect levels of VSCs. In addition to air samples, water and Sargassum samples were also taken and cultured for enterococci indicator bacteria. Average concentrations of total sulfur and H2S in the air were 43 ppb and 8.3 ppb, respectively. The Sargassum contained more than 10 times the concentration of enterococci CFUs than the ocean water. These findings further support claims that Sargassum impacts coastal air quality, demonstrating its potential to transmit harmful pathogens if a bioaerosol pathway is confirmed.