Impact of Hydrogen Sulfide on Lung Health: Study of Chronic Exposure of the Population Living on the Atlantic Coast and on the Caribbean Coast, in Martinique, During the Stranding Period and Outside the Stranding Period of Sargassum Seaweeds (SÉSAR)

  • End date
    Aug 31, 2024
  • participants needed
  • sponsor
    University Hospital Center of Martinique
Updated on 27 October 2022
Accepts healthy volunteers


Sargassum are pelagic brown sea algae. Two species grow on the surface of the ocean and drift freely with ocean currents in the form of slicks: the pelagic Sargassum fluitans and Sargassum natans.

Since 2011, massive strandings of Sargassum seaweed in the French West Indies are to be deplored. In recent years, strandings have increased. In Martinique, sargassum stranding occurs mainly on the Atlantic coast. The duration of stranding from one year to another is variable, but the period during which the stranding is maximum is between April and October.

The accumulation of strandings causes the compaction of algae and limits access to oxygen, which leads to anaerobic degradation which quickly results in the release of various gases, in particular hydrogen sulphide (H2S).

Acute H2S poisoning is well characterized clinically according to exposure (cutaneous, respiratory, ophthalmological, digestive, neurological symptoms, etc.). On the other hand, there are very few data available on the clinical effects of prolonged, repeated exposure and most often at low doses.

Among the toxic effects for which there are still uncertainties regarding long-term exposure to H2S are lung function, measured by spirometry, and airway inflammation, appreciable by measurement of FeNO (fractional exhaled nitric oxide).

The investigators consider it relevant to focus on the clinical and biological characteristics of the population exposed to sargassum in Martinique, in the field, assuming that exposure to sargassum H2S causes pulmonary effects measurable by spirometry and by FeNO, during the stranding period and outside this period.

Condition Obstructive Ventilatory Disorders
Treatment spirometry, Physical Examination, FeNO (fractional exhaled nitric oxide), Interrogation
Clinical Study IdentifierNCT05564546
SponsorUniversity Hospital Center of Martinique
Last Modified on27 October 2022


Yes No Not Sure

Inclusion Criteria

Adult participant (age greater than or equal to 18)
Participant living on the Atlantic coast in Martinique, close (less than 300 meters) to sargassum seaweed stranding areas (exposed group)
Participant living on the Caribbean coast, in Martinique (unexposed group)
Participant having been informed of the research
Participant having given his free, informed and express consent
Participant affiliated to a social security scheme

Exclusion Criteria

Minor Participant
Participant with a known respiratory or cardiac pathology
Participant with a cognitive state that does not allow him to answer the questionnaire
Participant who refused to participate in the study
Pregnant or breastfeeding women
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