O-39 Sargassum Invasions and Their Impact on Caribbean Shorelines: Exploring Environmental Violence and Potential Effects on the Human Neurological System

Methods:  This single-center retrospective cohort study is set at the tertiary-care sleep center of the University Hospital of the French Caribbean Island of Martinique. The records of patients having programmed functional polysomnography explorations from 01/01/2018 to 31/12/2022 were retrospectively reviewed and socio-demographic data, medical history and polysomnographic characteristics were collected.

Results:  685 patients were considered (mean age: 55 ± 16 years, 60 % women). Frequent medical histories were systemic hypertension (50.9 %) and diabetes (11.8 %). Related sleep apnea symptoms were as follows: 67.5% nycturia, 24.5% dyspnea, 24% headache. A total of 186 patients (27 %) were exposed to sargassum emissions. Compared with non-exposed patients, exposed ones had similar sleep apnea syndrome risk factors, but had increased levels of central sleep apneic (CSA) events. Multivariate regression retained only male gender and mean H2S concentration over a 6-month exposure period as independent predictors of an increase in CSA events. A minimal exposure length of 1 month generated a significant rise in CSA events, with the latter increasing proportionally with a cumulative increase in H2S concentration over time.

Conclusion:  This novel work adds to previous findings by our team describing, in exposed individuals, a symptomatologic presentation (general, respiratory, digestive, neurological, cardiological) suggestive of chronic exposure to average H2S doses <10 ppm, and a risk of early onset of preeclampsia in pregnant women living close (<2 km) to impacted coastlines.  Jointly, these studies now constitute a body of evidence strongly supporting a deleterious effect of sargassum-H2S on the health of individuals chronically exposed to low to moderate concentration levels over time. Further multidisciplinary studies targeting the cognitive functions and brain structures of exposed subjects should be considered.