Emerging impact on airway health by airborne red tide toxins following major hurricanes Helene and Milton at the Gulf coast

Red tide is an ongoing environmental health crisis that is fueled by hurricanes and tropical storms. The dinoflagellate Karenia (K.) brevis is indigenous to the waters of the Gulf of Mexico and the Caribbean and is primarily responsible for harmful algae blooms known as “red tide”. Its blooms recur in native regions and multiply to neighboring coastlines. Satellite data from Florida’s Gulf Coast shows escalating concern about red tide rooms, which can impact not only humans but also lead to extensive mortality events among marine animals and land animals that come in contact. Hurricanes and tropical storms, which are frequent in Florida during the hurricane season, stir up nutrient rich waters, fueling red tide algal blooms. Algae toxins are aerosolized with sea spray aerosol and carried inland by winds. One of the major organ systems targeted by the red tide toxin is the respiratory system. Studies suggest that coastal residents may experience 54% higher rates of respiratory diagnoses during red tide periods compared to non-red tide periods. Such diagnoses include bronchitis, pneumonia, asthma, and upper airway disease. Limited data in experimental animal models suggests that red tide can induce asthma-like features, though the mechanisms responsible remain unclear. Additionally, some data suggests that individuals with asthma or compromised airway function are more sensitive to the harmful respiratory effects of red tide algal aerosols. Building upon prior work from MPI Dr. Jang who has showed that red tide brevetoxin in sea spray aerosols undergoes degradation and produces free radicals with sunlight exposure, this proposal seeks to investigate the natural history of red tide blooms and effects of atmospheric aging on airway barrier function and inflammation using primary human airway cells. Our overarching hypothesis is that algal aerosol and toxins disrupts airway epithelial barrier function and induces airway inflammation to predispose individuals to develop asthma-like symptoms. We predict that the degree of airway inflammation and barrier disruption will coincide with the magnitude of the red tide algal bloom, with peak effects observed during peak algal bloom. We will directly collect red-tide sea spray aerosol in 3-5 locations impacted by red tide blooms until the red-tide has recessed. The collected algal aerosol will be resuspended in the Atmospheric Photochemical Outdoor Reactor (UF-APHOR) located in the University of Florida for characterizations and exposure studies. UF-APHOR is one of three large photochemical reactors worldwide that mimics the atmospheric process of algal aerosol under the ambient sunlight. The collected algal aerosol will be applied to normal and asthmatic human primary airway epithelia cultured at airway liquid interface. We will measure inflammation, ion transport mechanisms and barrier function through fluid secretion assays to investigate the adverse impacts of red tide on airway health. Project Number: 1R21ES037899-01 | Fiscal Year: 2025 | NIH Institute/Center: National Institute of Environmental Health Sciences (NIEHS) | Principal Investigator: Leah Reznikov (+1 co-PI) | Institution: UNIVERSITY OF FLORIDA, GAINESVILLE, FL | Award Amount: $416,924 | Activity Code: R21 | Study Section: Special Emphasis Panel[ZES1 MGE-S (TS)] View on NIH RePORTER: https://reporter.nih.gov/project-details/11229489