Salt water represents about 97.5% of all water on the planet. Despite its wide availability, it is not used for human consumption and many people believe that we are wasting an important source of this natural resource. But, after all, can we or can we not drink the water found in the seas and oceans?
Salt water, as available, cannot be consumed. This water is rich in sodium chloride, the same salt we use to prepare food, and excess salt in our body causes cells to start losing water through osmosis, which causes dehydration. It is estimated that the concentration of salts in drinking water is about seven times lower than in sea and ocean water.
Due to dehydration caused by ingesting salt water, the person begins to feel more and more thirsty. It is estimated that for every liter of salt water ingested, two liters of fresh water are needed to dissolve the entire amount of salt. It can be seen, therefore, that when there is a shortage of fresh drinking water, the ingestion of salt water can trigger a worsening of thirst.
In addition to this problem, seawater has some other salts that cause intestinal irritation. This irritation can trigger diarrhea and, consequently, lead to the loss of a greater amount of water.
Do not stop now... There's more after the advertising ;)
However, there are modern techniques that allow the population to use sea water. The process known as water desalination it is already carried out in several parts of the world and could be an alternative when water scarcity takes on alarming proportions.
The desalination of water, which in the eyes of many is a great step forward in the face of the current water crisis, presents a big problem: the cost. The creation of plants and the high consumption of electricity are two factors that make the production of drinking water from sea water more expensive.
Despite being a great source of water, the oceans and seas are still not a good alternative for human consumption. In addition to not being able to consume untreated water, the cost of making it drinkable is often unfeasible. Therefore, desalination should only be used as a last resort, when freshwater reserves are no longer available.
Before the water crisis we face, the main solution is for the population to consume consciously, reuse water and make the most of rainwater. The sustainable use of water resources is the most effective way to avoid rationing.
By Ma. Vanessa dos Santos
Would you like to reference this text in a school or academic work? Look:
SANTOS, Vanessa Sardinha dos. "Can we drink sea water?"; Brazil School. Available in: https://brasilescola.uol.com.br/biologia/podemos-beber-agua-mar.htm. Accessed on July 27, 2021.
