PFAS are industrial contaminants whose effects are just now starting to be understood. PFAS is a broad category that many chemicals fall under — so first, let's take a look at some common acronyms used when referring to specific types of chemicals within this group.
According to the Environmental Protection Agency (EPA), Per- and polyfluoroalkyl substances, or PFAS for short, are a group of man-made chemicals used to manufacture hundreds of products. PFAS are used in a variety of industries and can be found in the environment and human body. PFAS usage in the United States dates back to the 1940s.
Water is said to be "calcareous" (or "hard") when it contains too much calcium and magnesium. This calcareous water can have an impact on your body, especially on the skin and hair, causing dryness and itching.
Water is one of the most powerful solvents. Although it is difficult to see this over a short period of time, its ability to dissolve rock and sediment has nevertheless created some of the most spectacular landscapes in the world: the Grand Canyon is an impressive example. But by dissolving the rock and limescale all the way to your faucet, the water is enriched with calcium and magnesium: it becomes "hard".
Our planet’s water continuously changes state by advancing through a circuit known as the water cycle. One such step is rain, when water that had evaporated into the atmosphere flows back to earth. In doing so, it comes into contact with calcareous rocks and is loaded with sediment. This water is said to be calcareous or hard: saturated with minerals that it retains once it reaches our running water networks despite the treatment stages to make it drinkable.