Types of Salt Water
There are two types of salt water: seawater, which naturally contains salt and is found in the ocean; and salt water that is made artificially by adding table salt to a glass of drinking water. Both kinds of water are dangerous to drink, especially in large quantities.
Why Can't We Drink Salt Water?
Salt water causes dehydration instead of hydration. If you have tasted seawater, you're familiar with the high level of salt in the water. Drinking seawater or salt water creates a high level of sodium in your body, which would produce urine in an effort to remove the sodium. Thus, rather than adding more water to the body, the act of drinking salt water is more dehydrating than drinking no water at all. Additionally, in the case of seawater, there are thousands of bacteria and microorganisms swimming in every gulp of seawater, and these living creatures are unhealthy for the body to digest and process.
Salt Content of Seawater
Seawater contains about 35,000 ppm (parts per million) of saline, or salt. Our drinking water has some salt in it, but not nearly as much as is in seawater. For water to be deemed drinkable, it must contain less than 1,000 ppm of salt. While the water does still have a slight amount of salt, it is more hydrating than dehydrating.
The one way you are able to consume seawater or salt water is by desalinating it. Desalinating salt water might sound like the answer to some of the world's drought and water problems, but it is a very expensive and involved process that uses more energy to turn the water into something humans can drink than filtering water that does not contain salt.