What Exactly is Purified Water?
Purified water is water from any source, including tap water, that has been processed to remove impurities and contaminants to a very high degree. In the United States, for water to be labeled 'purified,' it must meet strict U.S. Environmental Protection Agency (EPA) and U.S. Food and Drug Administration (FDA) standards for bottled water, with a total dissolved solids (TDS) level of no more than 10 parts per million (ppm). This is achieved through various methods, which can significantly alter the water's composition.
Common Water Purification Methods
- Reverse Osmosis (RO): This process forces water through a semi-permeable membrane that filters out dissolved solids, bacteria, and other contaminants. RO is highly effective but can also remove beneficial minerals.
- Distillation: Water is boiled into steam, which is then condensed back into a liquid, leaving most contaminants behind. Distilled water is exceptionally pure but lacks all minerals, which can result in a flat taste.
- Deionization (DI): Using ion-exchange resins, this method removes ionized salts and minerals from the water. DI is typically used for industrial or laboratory applications where mineral-free water is essential.
- Filtration (Advanced): While basic filters improve taste, advanced systems often incorporate multiple stages, including carbon filters and UV treatment, to remove a wide range of contaminants, including bacteria and viruses.
The Health Implications: Benefits and Drawbacks
Drinking purified water offers several advantages, but it also comes with a few considerations, primarily regarding mineral content.
The Benefits of Drinking Purified Water
- Reduced Contaminant Exposure: The primary benefit is the significant reduction of harmful substances. Purification processes effectively remove heavy metals, bacteria, viruses, and chemicals like chlorine and lead, which may be present in some tap water.
- Better Taste and Odor: By stripping out impurities, purified water often has a cleaner, more neutral taste and is free of the chemical odors sometimes associated with tap water. This can encourage increased hydration.
- Safer for Vulnerable Individuals: Purified water is often recommended for infants, pregnant women, and people with compromised immune systems, who may be more susceptible to waterborne pathogens. Some brands sell specially purified distilled water for babies.
- Promotes Detoxification: With its high purity, purified water can assist the body's natural detoxification processes by helping to flush out waste products.
The Potential Drawbacks
- Lack of Essential Minerals: The most common criticism is that many purification methods, particularly distillation and some RO systems, remove beneficial minerals like calcium, magnesium, and potassium. Over time, relying solely on mineral-deficient water may lead to a mineral imbalance if not supplemented by diet.
- Flat Taste: The absence of minerals can give the water a bland or flat taste, which some people find unappealing. This can be a minor deterrent to drinking sufficient water throughout the day.
- Potential Environmental Impact: Bottled purified water contributes to plastic waste. Home purification systems, especially RO, can also generate wastewater, raising environmental concerns.
Purified vs. Other Types of Water: A Comparison
To make the best choice for your health and taste, it's helpful to understand the differences between purified water and other common options.
| Feature | Purified Water | Tap Water | Bottled Water | Spring Water |
|---|---|---|---|---|
| Source | Various (often municipal tap water) | Public municipal source | Various (can be purified, spring, etc.) | Underground spring |
| Treatment | Extensive treatment (RO, distillation) | Disinfection and basic filtration | Depends on the label | Naturally filtered, but still requires safety testing |
| TDS Level | Very low (under 10 ppm) | Varies widely by location | Varies; purified bottled water is low | Varies; generally higher than purified |
| Mineral Content | Low to non-existent (can be added back) | Varies; can contain beneficial minerals | Varies by brand and type | Contains naturally occurring minerals |
| Safety | Very safe; treated to remove most contaminants | Generally safe in most developed countries, but can have trace contaminants | Safe, but quality depends on the source and brand | Generally safe, but can be susceptible to contamination from source |
| Taste | Often described as neutral or flat | Varies widely; can have chlorinated taste | Varies by brand and mineral content | Refreshing, and mineral taste can be present |
Making an Informed Decision
The choice of whether to drink purified water depends on your specific circumstances, health priorities, and personal preferences. If you live in an area with a reliable public water system, tap water may be a safe and economical choice, though some may opt for basic filtration to improve taste. However, if your local tap water quality is questionable, or if you have specific health concerns, purified water can provide added peace of mind.
For those concerned about the mineral content removed during purification, several options exist. Many home reverse osmosis systems now include a remineralization stage to add healthy minerals back into the water. Alternatively, you can ensure a balanced diet rich in minerals to compensate for those lacking in your drinking water.
Conclusion
Yes, purified water is drinkable and is generally considered a very safe option for hydration due to the removal of harmful contaminants. The rigorous purification processes, such as reverse osmosis and distillation, ensure a high level of purity, which is especially beneficial for those in areas with questionable tap water quality or with specific health concerns. While the loss of minerals can be a consideration, it is not a significant health risk for most people, and there are straightforward solutions to address this concern. By weighing the benefits of purity against the drawbacks of mineral loss, individuals can confidently choose the best drinking water for their household. For those considering home systems, researching specific products and testing local water quality can help make the most informed choice. For further reading on water quality standards, the World Health Organization offers extensive guidelines.
