Water is not unique to the Earth, several studies have shown that water exists on other planets and moons in the solar system. This fact is a prelude to life and paramount in the case of hypothetical migrations out of planet Earth.
There is a big difference between salt water and fresh water on our planet. Only 3.5% of the total water is fresh water, whether drinkable or not (rivers, streams, ice at the poles and on the tops of the mountains), while the remaining 96.5% is salt water.
We might think that our existence is almost a miracle, especially when observing the percentage of drinking water available. Only 1% of this precious liquid is found in rivers, lakes and streams of the land area, while the remaining 99% is distributed in solid state in the mountains and poles (80%), and in a liquid state underground (the remaining 20%).
Water can contain microorganisms that are harmful to our health, to remove them and get drinking water is necessary to perform a process that consists of 4 stages: coagulation, flocculation, sedimentation (or settling) and filtration. These 4 stages are vital because, if this procedure is not followed, health can be seriously affected.
This is due to the difference between the levels of salinity of the human body and seawater. Seawater has a salinity level of 35 while our bodies only have a value of 9. Why is this important? Since an increase in the salinity of our blood by drinking seawater will cause the body to try to expel it through the urine, eventually the process will cause dehydration.
The water is considered to be the "universal solvent" because there are a lot of substances which can be diluted in water, even more than with any acid, including sulfuric acid.
At birth the human being is 75% water, the percentage decreases to 65% in adulthood. Around 65% of this water is stored in our cells, while the rest is circulating in the blood and other tissues.
Being approximately 70% of its composition, water is one of its vital elements. It is estimated that a dehydrated person may suffer a 15% drop in concentration and a 10% in short-term memory.
The answer varies depending on gender and age. For example, boys between 9 and 13 should consume about 2.1 litres of water, while girls only 1.9 litres. This figure changes for adults, optimal amount would be 2 litres of water for women and 2.5 litres for men.
A man can stand up to a month without eating, but not as much without drinking. It is estimated that, on average, a person can not survive more than five days without water before dying, depending on many factors such as age, sex, body mass, etc.
Thirst is the body's alert against dehydration, which is controlled by the hypothalamus. The body sends drink orders depending on the density detected in blood and other body fluids either by a deficit in the water concentration or by a high salt concentration.
Quite incredibly it is estimated that, of the total water covering the planet, only 0.007% is drinking water, which must supply nearly 7 billion people in the world.