Sargassum Lung Syndrome: Air Flow Obstruction and Bronchial Inflammation Are Observed After Prolonged Exposure to Sargassum Gas Emissions in the Eastern Caribbean.

Sargassum inundation of Caribbean and American shorelines is a growing environmental hazard. Hydrogen sulfide (H2S) and ammonia (NH3) produced by decomposing Sargassum could be involved in airway obstruction and bronchial inflammation. The study was undertaken to evaluate the effects of exposure to H2S and NH3 gases emitted during Sargassum decomposition based on measures of airflow obstruction and bronchial inflammation in a study population from the French Caribbean Island of Martinique. Ambient air exposure was estimated by the closest ground H2S/NH3 sensor. Lung function and bronchial inflammation were evaluated by spirometry and fractional measurement of nitric oxide in the exhaled air (FeNO), respectively. Multivariate logistic and linear regression were applied to analyze associations between cumulative Sargassum H2S/NH3 exposure and risk of airway obstruction and FeNO changes. The analyses also took into account the effects of confounding factors, notably air pollution. Among the 335 study patients, 72% were living in Sargassum-impacted zones. Compared with nonexposed patients, exposed patients had lung measures showing airway obstruction and increased FeNO levels. Exposed patients with asthma presented a two-fold rise in FeNO levels. Multivariate modeling retained mean cumulative concentrations of Sargassum H2S and NH3 as independent predictors of increased risk of airway obstruction and bronchial inflammation. The present study highlights a potential association between impaired lung function and exposure to Sargassum H2S and NH3 during coastal stranding episodes. Present study results strongly support the deleterious effect on the respiratory health of individuals chronically exposed to Sargassum gas emissions.