Evaluating the ten-year health impact of hydrogen sulfide (H2S) and ammonia (NH3) exposure from sargassum seaweed invasions in the Caribbean: Public health implications.

Since 2011, the Caribbean region-including Martinique, Guadeloupe, and French Guiana-has experienced increasing invasions of Sargassum seaweed, leading to significant environmental, economic, and public health challenges. This study evaluates the health impacts of hydrogen sulfide (H₂S) and ammonia (NH₃) emissions from decomposing Sargassum on affected populations. Data were collected from 850 patients admitted to the University Hospital of Martinique between January 2018 and September 2024, all of whom had been exposed to Sargassum emissions for an average of 2-3 months annually. Reported symptoms included neurological (80%), respiratory (80%), and digestive (70%) disorders, as well as central sleep apnea (60%). Pulmonary inflammation was assessed through spirometry and fractional exhaled nitric oxide (FeNO) levels. Psychological and social impacts were also documented. Findings indicate a toxicological syndrome associated with chronic Sargassum exposure, resembling acute H₂S inhalation at low concentrations. This study underscores the urgent need for multidisciplinary research to mitigate these health impacts, calling for immediate attention from governments, international stakeholders, and environmental experts.