Understanding Rainwater: Is it Safe to Drink?

 Rainwater, also known as precipitation is formed when water interacts with the air and then condenses. It is pure water with very low salt content. If we think of rain as natures way of "air cleansing" for a hours we'll find that it contains impressively low levels of pollutants and particulate matter. However a small portion of particles and pollutants inevitably make their way to the ground.

When determining if water is drinkable or potable it's not about its purity. We also consider the mineral content in both public mains waters and mineral waters. These waters contain mineral salts that are important for our biological processes. So being clear odorless tasteless, colorless and free from microorganisms and chemicals isn't enough for water to be considered drinkable.

There are guidelines that define the maximum allowable amounts of toxic substances, in water. Interestingly rainwater rarely exceeds these limits. However what rainwater lacks compared to sources is an adequate amount of salts.

The Significance of Water Hardness

Water hardness, which indicates the presence of mineral salts is measured in degrees French (°F). As per DL 31/01 regulations water is considered safe for drinking if its hardness (measured in degrees French) ranges from 15 to 50. Each degree French corresponds to 10 mg/L of calcium carbonate (CaCO3) resulting in a calcium carbonate concentration range of 150 500 mg/L.

Final Verdict; Can Rainwater Be Consumed?

Considering these details it is not advisable to consider rainwater as suitable for drinking. In fact consuming amounts of rainwater could potentially lead to severe health complications due, to its extremely low mineral salt content.  In the Rainwater, researchers found that concentrations of perfluoroalkyl substances (pfas) have reached worldwide values above the limits set by U.S. drinking water guidelines.

Pfas are very persistent molecules that have serious health effects, and can cause cancer, among other things.