Tap water or bottled water?
According to a study by the University of Patras, water supply networks in cities are safe!
Despite the extremely high price of bottled water compared to tap water, in recent years their worldwide demand has increased dramatically due to the common perception that the water supply network is not as safe as it could be.
The huge increase in interest in bottled water has contributed significantly to the need for proper hydration before and after physical activity, the proposed healthy lifestyles and effective bottling companies’ promotional campaigns.
The increasing pollution of surface and underground water resources has resulted in degradation of tap water and has given rise to the creation of large bottled water companies. Setting up a water bottling business is relatively low cost and trading in bottled water is very profitable, with very good investment prospects.
However, with the development of water purification technology, there are cases where the water of the water supply system is as good or better than bottled water, such as the water of New York City, Munich and Patras.
There are several types of bottled water: (a) natural mineral water comes from groundwater containing a constant level of metals and trace elements; (b) spring water comes from underground aquifers from (c) purified water comes from surface or groundwater, which has been treated to be suitable for public consumption, (d) artesian water ( artesian water) is water derived from a from a well, which passes through a water layer where the piezometric level of water is higher than the top of the water layer, (e) sparkling water which, after relative treatment and possible addition of carbon dioxide, contains the same percentage of carbon dioxide it originally had at source and (f) well water derived from underground aquifers.
Tap water can be contaminated by various chemical, microbial and natural sources of pollution. Some infectious agents can be more easily controlled in bottled water than in tap water, which flows through the distribution system pipes. However, some substances may prove more dangerous in bottled water than tap water, because bottled water is stored for quite long periods in bottles and at higher temperatures than water distributed through the water supply network.
The water is bottled in plastic or glass bottles. However, the plastic bottles are made of PET (polyethylene terephthalate). For PET production, 90% of producers use the antimony trioxide catalyst, which is considered by the World Health Organization as a potential carcinogen. Also, the majority of plastic bottles are not recycled and end up in landfills where they remain unbroken for several decades.
Natural waters contain various inorganic and organic constituents, which may be dissolved or suspended. The specifications for the quality of bottled water are the same as those for drinking water. The sum of divalent cations, mainly calcium and magnesium, causes water hardness. A certain amount of hardness disappears if you boil water.
The term hardness is well known because it is often used to characterize natural waters that do not foam sufficiently for washing.
This is due to the multivalent cations present in the water, which react with the stearic acid content of the soap to form insoluble salts, which do not allow good foam to be washed. Also, the term hardness denotes water which upon boiling creates a precipitate of calcium carbonate which is commonly observed in household utensils (e.g., pots) and in hot water pipes.
The most common hardness units are mg / L equivalent calcium carbonate (CaCO3). The waters are classified on the basis of their total hardness in soft (0-75 mg / L CaCO3), moderate (75-150 mg / L CaCO3), hard (150-300 mg / L CaCO3) and very hard (> 300 mg / L CaCO3).
Although many have argued that hard water can aggravate various diseases (eg colic, hypertension), these effects are uncertain. Studies have also suggested that hard water could have a beneficial effect on heart disease because of the calcium it contains. This conclusion is very controversial because hard water is associated with high concentrations of total soluble solids, which are considered to be beneficial against heart disease.
Therefore, there is no specification that imposes an acceptable maximum for water hardness.
The bottled water on their label includes the typical components of chemical analyzes along with the conductivity, pH and total soluble solids values.
This information is characteristic of water quality, which is not necessarily understood by the average consumer. The prices of the various bottled waters circulating in the Greek trade vary considerably. Most often the price of bottled water is representative of their quality, but not always.
Most of the bottled water (Greek and foreign) widely circulated in the Greek market was carefully examined and their hardness was calculated based on the chemical analysis data shown on the labels.
It was noted that the values of the standard ingredients and the hardness of the 37 bottled waters tested showed substantial fluctuations and volatility. Most of the bottled water is hard and some are very hard. Also, as shown by other studies, the hardness of the bottled water is directly related to the conductivity and concentration of total soluble solids.
Bottled water is essential for some activities and uses, but clean water at a fairly affordable price is a basic right for everyone. By protecting rivers and streams, we can help public utilities deliver good quality drinking water at an affordable price while helping to reduce the demand for bottled water.
