What if we Drink only Seawater? and Why can’t people drink seawater?
On average seawater has a salinity of about 3.5%. When we drink seawater, water, as well as excess salt, get absorbed in our blood. One of the functions of our kidneys is to remove this excess salt from our blood. But urine produced by kidneys has a salt concentration. Which is less than the 3.5% of that of sea-water. Hence it needs more water to remove all the excess salt. As a result, we feel thirsty after drinking seawater. Excess seawater consumption can lead to dehydration. Secondly, excess drinking of seawater. Will also hinder the blood purifying process of our kidneys. How? Because of solute concentration inside the filtering units of our kidneys. Will be lower than that of the highly saline blood. Hence, due to osmosis, blood doesn’t get purified.