The famous American specialist Paul Bragg believed that the human body absolutely did not need table salt, and called it a poison.
The fallacy of such views is now considered fully proven. Salt is vital for man, as well as for all other living things. Salt is involved in maintaining and regulating water balance in the body. Sperm, urine, blood, tears, sweat, and almost any human organ actually contain salt, without which cells cannot work. If there is no water and salt, the cells do not receive nutrition and die from dehydration. With a chronic lack of salt in the body, a fatal outcome is possible.
On the other hand, death is inevitable with a single overeating of salt. The lethal dose is 3 grams per kilogram of body weight. For example, for a person weighing 80 kg, it will be fatal to eat about 240 grams per meal. By the way, approximately this amount of salt is constantly present in the body of an adult.
The average daily intake of salt for an adult is 3-5 grams of salt in cold countries and up to 20 grams in hot countries. The difference is caused by the different intensity of sweating in hot and cold climates.
There are many different salts, some of which can also be eaten. But sodium chloride (NaCl) is most suitable for eating, and it is precisely its taste that we call salty. Other salts have an undesirable bitter or sour taste, although they may also have some value in the human diet. The infant formula contains three salts - magnesium chloride, potassium chloride and sodium chloride.
Table salt serves as a source of formation in the stomach of hydrochloric (hydrochloric) acid, which is an integral part of gastric juice.
With low acidity, doctors prescribe a weak aqueous solution of hydrochloric (hydrochloric) acid to the patient, and with high acidity, he experiences heartburn and is recommended to take baking soda. It neutralizes excess acid.
Table salt has mild antiseptic properties; The 10-15% salt content prevents the development of putrefactive bacteria, which is the reason for its widespread use as a food preservative.
In ancient times, salt was mined by burning some plants in fires; the resulting ash was used as a seasoning.
Ancient peoples valued salt as much as gold. For example, part of the salary of Roman soldiers (lat. Salarium argentum) was given out with salt (lat. Sal); from here, in particular, came the English. salary ("salary").
Already two thousand years BC. the Chinese have learned to obtain table salt by evaporating sea water.
When seawater freezes, the ice becomes unsalted, and the remaining unfrozen water becomes much saltier. By melting ice, you can get fresh water from sea water, and salt was boiled from brine with less energy consumption.
Pure sodium chloride is a non-hygroscopic substance, i.e. does not absorb moisture. Magnesium and calcium chlorides are hygroscopic. Their impurities are almost always found in table salt and it is because of their presence that the salt damp.
The world's largest salt marsh is the Uyuni salt marsh in Bolivia (photo below). Due to its large size, flat surface and high reflectivity in the presence of a thin layer of water, the Uyuni Salt Flats is an ideal tool for testing and calibrating remote sensing instruments on orbiting satellites.
The world consumption of table salt exceeds 22 million tons per year. Each person consumes on average about 8 kg of salt per year. One third of the salt produced is evaporated from seawater.