Different Types of Bottled Water
Bottled water that is labeled drinking water is water that has been partially purified, with its minerals allowed to remain, or it is water that has been thoroughly purified (completely demineralized) and then had minerals replaced to improve taste.
Although these minerals are added for taste, they are beneficial for health as well. This brings up a question: Are the few kinds of minerals that are re-added to bottled water as beneficial as the wider diversity of naturally occurring minerals that were in the water prior to treatment? No one knows for sure. But what is known for sure is that the added minerals are better than no minerals.
Also, adding minerals to drinking water makes it much less aggressive than purified water, so there is less likelihood of toxic chemicals leaching from containers into the water.
Purified water in itself will not harm you, even though minerals in water are definitely beneficial However, there is a problem specific to bottled purified water. Purified water has had all of it's foreign constituents (which are mostly minerals) removed. This is not a natural state. In the natural state, water contains many different kinds of minerals. Once purified, water will try to return to its natural state by reacting chemically with the material it contacts. Because of this tendency, purified water is "aggressive" water.
When purified water is placed in plastic bottles, it tends to leach out any chemicals in the plastic that are loosely bonded. These chemicals then enter the water (in minuscule amounts). The longer the purified water remains in a plastic bottle, and the higher it's temperature, the greater the chance of chemicals entering the water.
While there is no overriding evidence to prove that this is harmful, the long term effect of these chemicals is unknown. Some studies have shown a link between chemicals leached from plastic water bottles and disorders of the human immune system, but this is far from conclusive.
In my opinion, based upon research I have surveyed, the "aggressiveness" of purified water may cause long term health problems. Because of this, I recommend that you do not buy purified water in plastic bottles.
Specialty water includes water products with added flavors and/or carbonation, such as lemon flavored sparkling water. Some of these products use water from naturally occurring springs and some use tap water.
Usually sold in small containers, these specialty waters are legally categorized as beverages - that is, it is assumed that, like beer or juice, they will be consumed only occasionally and not daily. Because of this, specialty waters come under a set of regulations that are less stringent than those for drinking water. For occasional use, specialty water products are probably no more or less dangerous than any other bottled beverage.
Natural Source Water
Natural source bottled water includes all those water products whose source is claimed to be naturally occurring spring or aquifer (underground reservoir). The problem with these products in general, is that naturally occurring water is not always healthy or safe water, even though it generally contains a high level of beneficial minerals.
The water from some spas, for example, has been found to contain abnormally high levels of radioactivity; other spring waters have been shown to contain high amounts of toxic organic chemicals and toxic heavy metals, such as lead and cadmium. Even prestige brands of spring water have occasionally been found to contain pollutants.
While natural spring water bottlers regularly test their water for several common pollutants, they generally do not test for a wide range of possible pollutants. While most natural source water is safe most of the time, there is no foolproof way to know if a particular brand is safe at any particular time without having it tested.
Also see Facts about Distilled Water