zombie + water

alkup. 11.6.2023

Fresh water drowning (90% of drowning deaths occurred in fresh water)

Unlike salt water, fresh water is practically pure water. This means that it has a very low solute concentration and therefore a very low osmolarity. As a result, fresh water is hypotonic to our blood. For this reason, when we expose the cells of our body to fresh water, the water tends to enter the cells through the membrane through the process of osmosis.

When this happens, two things can happen:

• When water enters the cell, it becomes hypotonic to our blood plasma and therefore the cell releases excess water into the bloodstream.
• That the cell does not remove excess water and swells before it bursts, a process known as osmotic lysis.

Both of these two processes are very dangerous when we drown in fresh water.

Consequences of excessive water absorption into the body

First, fresh water doesn't break our skin cells because we have several layers of dead cells and keratin that don't let water in freely. However, when we inhale water and it enters the lungs, it comes into direct contact with the lung cells, which are not protected by skin layers. On the contrary, they are fully optimized to facilitate the passage of gases from the air to the bloodstream.

As a result, fresh water easily enters our blood, increasing its volume and diluting it at the same time.

The same thing happens when we swallow large amounts of fresh water (that is, when we swallow it and it goes into our stomach and then into our intestines). Both pathways cause the body as a whole to absorb large amounts of water when we drown in fresh water.

Now come the secondary consequences of this excessive water absorption. Excess water dilutes the blood, reducing its osmolarity. The decrease in osmolarity causes red blood cells (already thinner due to excess water) to swell and burst (osmotic breakdown of blood cells or hemolysis). This reduces the blood's ability to carry oxygen to our body tissues, even if we manage to remove all the water and restore breathing.

On the other hand, the dilution severely alters the ionic balance of the blood and this can cause ventricular fibrillation in the heart followed by cardiac arrest in just three minutes.

Osmotic breakdown of other tissues

Blood cells, such as red blood cells, are not the only ones that can suffer the effects of osmotic breakdown. Lung cells can also burst from the absorption of pure water by osmosis. This can cause severe damage to the lung tissue and further limit oxygen intake after breathing is restored.

The main consequence of these side effects of contact with fresh water is that many people who drown in fresh water and are rescued in time do not die immediately from hypoxia, but die hours later from heart failure and other complications.