Sargazo: la irrupción atípica de un ecosistema milenario / Sargassum: the atypical irruption of an ancient ecosystem

Resumen El sargazo es un ecosistema marino milenario que circula en el sentido de las manecillas del reloj en el Océano Atlántico. A partir de 2011, el alga flotante que lo compone ha comenzado a recalar en playas de 19 países del Caribe, con consecuencias ambientales, sanitarias y económicas que deben atenderse con urgencia.

Abstract Sargassum constitutes an ancient marine ecosystem that circulates clockwise on the Atlantic Ocean. Upon 2011, the pelagic seaweed which is the main component of sargassum started to reach beaches on 19 Caribbean countries, with environmental, health and economic impacts that need to be addressed urgently.

Cognitive functions changes in Egyptian sewage networks workers

Hydrogen sulfide is a toxic gas about which much has been written. It constitutes one of the most serious chemical hazards to which sewage network workers are exposed to. The current work aimed at assessment of cognitive dysfunctions among workers of sewer networks and the relation of these changes, if any, to the level of exposure to the biomarker, urinary thiosulfate. A trial for setting a screening test for cognitive function change. The work was conducted among 34 male workers involved in the maintenance of the sewage network and a matched unexposed control group [n = 21]. The participants were subjected to clinical neurological examination, estimation of urinary thiosulfate as hydrogen sulfide exposure biomarker, and assessment of cognitive functions changes by using neurophysiological [simple reaction time, P300 test] and neuropsychological tests [Wechsler Memory Scale] and frontal executive functions. Clinical neurological history revealed significantly higher neurological symptoms [headache, memory defects, lack of concentration] among exposed workers compared to their controls [P < 0.05]. Marked elevation of urinary thiosulfate was observed among the exposed workers [P < 0.001] although this elevation was not correlated with the duration of exposure. Exposed workers showed poor performance of most of neuropsychological tests compared to control subjects. Significantly prolonged simple reaction time and delayed P300 latency were found among sewer network workers. Most of exposed workers had significantly lower Mini-Mental State Examination [MMSE] scoring than that of the controls [P < 0.001]. MMSE was significantly correlated with other neuropsychological tests. Exposure of sewer network workers is associated with significant cognitive dysfunction which can be screened by applying MMSE annually as a screening test of the exposed workers

Hydrogen sulphide gas poisoning aboard a fishing trawler: A report of four fishermen

Hydrogen sulphide is a colourless; foul-smelling gas that results from the decay of organic material. It is a by-product of various industrial processes; including the processing of fish; and is an important cause of work-related sudden death. Its toxicity is mainly due to its inhibition of oxidative phosphorylation in human metabolic pathways. Although there is some anecdotal evidence to suggest that the early use of amyl nitrate and hyperbaric oxygen is beneficial; supportive care remains the mainstay of therapy. This report highlights an incident during which four anchovy fishermen exposed to this gas; resulted in one fatality; two Intensive Care Unit admissions for pulmonary oedema and one minor case of bronchial irritation. This incident illustrates the need for more stringent enforcement of health and safety regulations in the fishing and seafood processing industry

Some morphologic and physiologic responses of tomato plants to hydrogen sulphide

Fifty and Hundred ppm of H2 were supplied to tomato plants growing under field conditions. The results indicated that all growth parameters studied decreased. The reduction became greater when concentration and/or number of treatments increased. H2S induced significant inhibitory effects on photosynthetic activities, accumulation of soluble sugars, biosynthesis of polysaccharides and most of the soluble nitrogen. H2S greatly reduced the activities of peroxidase nitrate reductase and glutamate dehydrogenase enzymes. H2S also showed effects on different amino acid levels