We cannot drink sea water because ingesting it can cause serious problems of dehydration and diarrhea.
Have you ever wondered how you would get water if you were wrecked? The answer to this question is often sea water, however, ingestion of this substance can cause serious damage to health.
Salt water represents about 97.5% of the total water on the planet and differs from fresh water in that it has a large amount of dissolved salts. In sea water, we find a salinity of 30% or more, while in fresh water the values are less than 0.5%.
Blood, like water, has salts, however, the amount is extremely low. When we ingest seawater, a large amount of salt reaches the digestive system, which causes the body to try to eliminate this excess. In an attempt to dilute the salt, the body begins to lose water through osmosis, that is, the water tends to leave the less concentrated place (blood) to the more concentrated one. Excessive water loss triggers a problem known as dehydration , which, if not treated properly, can lead to death.
As dehydration sets in, the person begins to feel more thirsty, a signal from the body that indicates that the body needs water. At this point, the ideal is to drink fresh drinking water. If salt water is ingested, the process can get worse and lead to death.
Another problem resulting from the ingestion of sea water is the existence of some salts that can irritate the intestine and cause diarrhea . This process is also dangerous because the loss of water through the stool can also lead to dehydration.
So, if you are stuck in the sea, the ideal is not to ingest salt water and look for other ways to hydrate yourself. A person may be able to meet his needs by drinking rainwater, removing water from food, such as fish, and using a simple evaporation technique. To obtain fresh water through evaporation, simply place salt water in a container and cover it with a plastic bag or other material. After evaporating, the water vapor reaches the material that is covering the container and condenses, forming small droplets of water free of salt. Despite being a small amount, this can help keep the body functioning.
It is worth mentioning, however, that today there are techniques that allow sea water to be treated and become drinkable. This process is called desalination and is already a reality in several parts of the world. The problem with this technology is that the expense with the construction of the plants and the energy for their realization is high, which makes the technique unfeasible in several places. Sea water is a potential source of drinking water, but the ideal is to invest in the preservation of fresh water sources and the conscious use of this resource, which are more economical measures.