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gepost door: roosmcd op 18/10/07 01:12 |
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Laatst was mij dit stukje opgevallen:
Bron New Scientist
Quote:
"Drowning
The "surface struggle" for breath
Death by drowning has a certain dark romance to it: countless literary heroines have met their end slipping beneath the waves with billowy layers of petticoats floating around their heads. In reality, suffocating to death in water is neither pretty nor painless, though it can be surprisingly swift.
Just how fast people drown depends on several factors, including swimming ability and water temperature. In the UK, where the water is generally cold, 55 per cent of open-water drownings occur within 3 metres of safety. Two-thirds of victims are good swimmers, suggesting that people can get into difficulties within seconds, says Mike Tipton, a physiologist and expert in marine survival at the University of Portsmouth in the UK.
Typically, when a victim realises that they cannot keep their head above water they tend to panic, leading to the classic "surface struggle". They gasp for air at the surface and hold their breath as they bob beneath, says Tipton. Struggling to breathe, they can't call for help. Their bodies are upright, arms weakly grasping, as if trying to climb a non-existent ladder from the sea. Studies with New York lifeguards in the 1950s and 1960s found that this stage lasts just 20 to 60 seconds.
When victims eventually submerge, they hold their breath for as long as possible, typically 30 to 90 seconds. After that, they inhale some water, splutter, cough and inhale more. Water in the lungs blocks gas exchange in delicate tissues, while inhaling water also triggers the airway to seal shut - a reflex called a laryngospasm. "There is a feeling of tearing and a burning sensation in the chest as water goes down into the airway. Then that sort of slips into a feeling of calmness and tranquility," says Tipton, describing reports from survivors.
That calmness represents the beginnings of the loss of consciousness from oxygen deprivation, which eventually results in the heart stopping and brain death." |
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| Manos esto var a lastimar |
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. Maar eigenlijk viel mij ook vooral het stukje op dat een groot deel van de mensen verdrinken vlakbij een stuk waar ze veilig zouden zijn geweest. De afgelopen tijd heb ik gewoon iets te vaak van het soort verhalen gehoord dat er toch niets kan gebeuren.... 
