Central sleep apnea and exposure to ambient hydrogen sulfide emissions from massive strandings of decomposing sargassum in the Caribbean

• Published in: The Science of the total environment Vol. 912; p. 168886
• Main Authors: Banydeen, Rishika, Lacavalerie, Mickael Rejaudry, Florentin, Jonathan, Boullanger, Carole, Medhaoui, Hossein, Resiere, Dabor, Neviere, Remi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20.02.2024; Elsevier
• Subjects: Apnea-hypopnea index; Central nervous system; Central sleep apnea; Hydrogen sulfide; Life Sciences; Sargassum; Sleep disordered breathing; Hydrogen sulfide; Central sleep apnea; Sargassum; Sleep disordered breathing; Central nervous system; Apnea-hypopnea index
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.168886

Sargassum invasion of Caribbean and American shorelines is a recurring environmental hazard. Potential health effects of long-term chronic exposure to sargassum gaseous emissions, notably hydrogen sulfide (H2S), are overlooked. H2S plays an important role in neurotransmission and is involved in generating and transmitting respiratory rhythm. Central sleep apnea (CSA) has been attributed to the depression of respiratory centers. Evaluate the effects of exposure to sargassum-H2S on CSA. This study, set in the Caribbean, describes the clinical and polysomnographic characteristics of individuals living and/or working in areas impacted by sargassum strandings, in comparison with non-exposed subjects. Environmental exposure was estimated by the closest ground H2S sensor. Multivariate linear regression was applied to analyze CSA changes according to cumulative H2S exposure over time. Effects of air pollution and other sargassum toxic compounds (NH3) on CSA were also controlled. Among the 685 study patients, 27 % were living and/or working in sargassum impacted areas. Compared with non-exposed patients, exposed ones had similar sleep apnea syndrome risk factors, but had increased levels of CSA events (expressed as absolute number or % of total sleep apnea). 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. This pioneer work highlights a potential effect of sargassum-H2S on the central nervous system, notably on the modulation of the activity of the brain's respiratory control center. These observations, jointly with previous studies from our group, 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. Exposure to hydrogen sulfide emissions from decomposing sargassum induces increased frequency of central sleep apnea. [Display omitted] •Massive sargassum beachings produce toxic gases during decomposition of the algae.•Nearby populations are chronically exposed to such emissions containing H2S and NH3.•H2S regulates many neurological functions including central breathing regulation.•Sargassum H2S exposure is associated with a rise in central sleep apnea events.•Sargassum NH3 or air pollution had no significant effect on central sleep apnea.