Human Swimming - Risks

Risks

There are many risks associated with voluntary or involuntary human presence in water, which may result in death directly or through drowning asphyxiation. Swimming is both the goal of much voluntary presence, and the prime means of regaining land in accidental situations.

Most recorded water deaths fall into these categories:

• Panic where the inexperienced swimmer or non swimmer becomes mentally overwhelmed by the circumstances of their immersion, leading to sinking and drowning. Occasionally panic can kill through hyperventilation even in very shallow water.
• Exhaustion where the person is unable to sustain effort to swim or tread water, often leading to death through drowning.

An adult with fully developed and extended lungs has generally positive or at least neutral buoyancy, and can float with modest effort when calm and in still water. A small child has negative buoyancy and will either sink rapidly or have to make a sustained effort to stay near the surface.

• Hypothermia where the person loses critical core temperature, leading to unconsciousness or heart failure.
• Dehydration from prolonged exposure to hypertonic salt water, less frequently salt water aspiration syndrome where inhaled salt water creates foam in the lungs that restricts breathing.

Hypothermia and dehydration also kill directly, without causing drowning, even when the person wears a life vest.

• Blunt trauma in fast moving flood or river water.

Less common are

• Other adverse effects:
  • Exostosis is an abnormal bony overgrowth narrowing the ear canal due to frequent, long-term splashing or filling of cold water into the ear canal, also known as surfer's ear.
  • Infection due to water-borne bacteria, viruses, or parasites.
  • Chlorine inhalation (in swimming pools).

• Adverse encounters with aquatic life:
  • Stings from sea lice, jellyfish, fish, sea shells, and some species of coral.
  • Puncture wounds caused by crabs, lobsters, sea urchins, zebra mussels, stingrays, flying fish, sea birds, and rubbish.
  • Hemorrhaging bites from fish, marine mammals, and marine reptiles, occasionally resulting from predation.
  • Venomous bites from sea snakes and certain species of octopus.
  • Electrocution or mild shock from electric eels and electric rays.=))

Around any pool area, safety equipment and supervision by personnel trained in rescue techniques is important. It is required at most competitive swimming meets, and is a zoning requirement for most residential pools in the United States.