Water Purity and Its Meaning

　　Decoding the Illusion of Water Purity

　　When the phrase "water purity" is mentioned, what thoughts arise? You might ponder, "How pure is the water, genuinely?" However, upon further examination, defining purity is a complex task. What does "pure" water actually mean—freedom from contaminants or pollutants? In the United States, the EPA considers "pure" water to be free of bacteria and viruses, yet purity goes beyond this definition.

　　H2O, a combination of hydrogen and oxygen, in its most pristine state, would only contain these elements. But such water is scarce outside of laboratory conditions. Even in labs, obtaining pure water is a challenge. For example, bacterial contamination can compromise sanitized water, flourishing without the presence of nutrients. To avoid metallic contamination, lab water purifiers employ plastics, which bacteria can use as a carbon source, introducing additional contaminants upon their death. Uncontrolled bacterial growth can interfere with laboratory procedures.

　　When it comes to drinking water, "pure water" commonly pertains to bacterial content rather than chemical pollutants. Nevertheless, bacteria are not the only concern; they also generate endotoxins and nucleases. Endotoxins, which are fragments of Gram-negative cell membranes, serve as potent immune stimulants that can potentially lead to sepsis and death. Ultraviolet irradiation efficiently destroys microorganisms, lowering bacterial counts and lightening the load on subsequent purification steps.

　　The concept of "pure" water is a fallacy. Water, as the universal solvent, inherently collects particles and minerals, whether in the form of precipitation or as it moves through streams and rivers. It gathers contaminants such as airborne mercury.

　　Consumers can strive for "healthy" water by identifying and eliminating harmful contaminants. The conversation around water quality is transitioning from "pure" to "healthy," recognizing that the latter is attainable. Healthy water has an optimal pH range of 7.2 to 7.6 and is free from contaminants like chlorine, chloramines, and trihalomethanes, among others, thanks to suitable treatment methods.