It is impossible to imagine the seashore without the bitter smell of salt water, which is strongly associated with summer vacations and the hot sand of the coast. Nevertheless, from the very childhood, everyone knows for sure that it is categorically impossible to drink sea water, although many do not understand why.
At first glance, it seems that water is water, all equally transparent and flowing freely. Despite the external similarity, sea and fresh water have different chemical and physical properties, which is the reason for the impossibility of drinking salt water. This reason lies in human physiology, which is not adapted to the increased content of salts dissolved in sea water. During the day, an adult should drink about 3 liters of water, and this amount is necessary to maintain the normal functioning of all organs and systems. This volume is not the net volume of water you drink, but the liquid that you absorb with food. But at the same time with this liquid you take a certain amount of table salt. This is an important step in maintaining the water-salt balance, since a person cannot live long without salt. However, seawater contains so many different salts that the body's excretory system cannot cope with. In a normal situation, when such an amount of salts gets into the blood, the body tries to remove them as soon as possible, but this will require much more water than the person consumed. The thing is that not all the liquid absorbed by a person is excreted from the body in the form of urine, but about a third of it. Therefore, when using sea water, the body finds itself in a vicious circle, in which more and more liquid is required to remove salts, and an increase in the amount of sea salt will provoke an increase in the amount of salt in the blood and a violation of the water-electrolyte balance of the body. Sea water is not suitable for drinking, not only for humans, but also for all other warm-blooded animals. The kidneys cannot cope with such a salt content in the body, so after a very short time they begin to fail. More often than not, people are forced to drink seawater due to shipwrecks in the open ocean, when there is no other way to survive. It is believed that such drinking can prolong life by 2-3 days, but it is not known whether such a risk is justified, since it is quite possible that salts will cause damage to the body much more than the forced refusal of water.