Bottled drinking water has become quite commonplace nowadays, but is drinking it healthier than water from the tap?
WITHOUT clean, safe, drinking water, a human being can only survive for a few days before dying.
Water forms, on average, about 60% of our body composition.
It performs various invaluable functions, including helping to maintain body temperature, forming the bulk of our blood, and serving as a medium to transport nutrients and wastes around our body.
Human beings lose water on a daily basis through processes like urinating, sweating and breathing, among others.
Therefore, it is essential that these water losses be replaced in order to keep the body working well, and to maintain the proper balance of water within the human body.
This is mainly achieved through drinking sufficient quantities of water every day. (See Adequate amounts)
It’s in the pipes
While Malaysians do receive safe drinking water through their taps, there is also a huge demand for bottled drinking water, as can be seen by the numerous shelves of such bottles in local hypermarkets and supermarkets.
According to Associate Professor Dr Azrina Azlan, this could be due to public perception that water from particular taps emits a certain odour or tastes a peculiar way that is not palatable.
The nutritionist from Universiti Putra Malaysia’s Faculty of Medicine and Health Sciences had previously led a study comparing the mineral content of tap water, bottled drinking water and mineral water in Peninsular Malaysia.
She says: “From surveys, I found that some people mention that tap water can sometimes taste or smell a particular way. But that is their personal perception.
“Based on our study, the level of the selected minerals were generally below the permitted levels. So, in terms of safety, tap water in Malaysia is safe.”
While there were a couple of tap water samples that had certain elements above the permitted standard, Assoc Prof Azrina opines that this was likely due to the older pipes in the area, rather than the tap water itself.
Prof Datuk Dr Mohd Jamil Maah from Universiti Malaya’s Faculty of Science also believes that any problems with tap water is likely to be caused by the pipes that deliver the water from the treatment plants, rather than the treatment process itself.
As one of the consultants who helped the Health Ministry develop the Drinking Water Quality Index in 2008, Prof Jamil says that the treatment process of tap water is regularly monitored according to international water quality standards.
The professor of chemistry says: “What comes out from the water treatment plant is clean, what comes to the community depends on the pipes, which are installed by various sources, depending on how each state handles it.”
He adds that nowadays, many people usually filter the water they receive at home. This process usually gets rid of any sediments or larger physical materials that might have accumulated in the water on its way to the community from the treatment plant.
“The pipe from the source can be several kilometres long. Sometimes, the water may be stagnant at certain spots, so there might be sand or moss there, which can be carried along by the water.”
Prof Jamil adds that the public should also be aware that some taps in their house, like the kitchen taps, are directly linked to the pipe system, whereas other taps like the bathroom ones, are connected to the house’s own water tank.
“We shouldn’t always blame the authorities, we also have to ask ourselves how often do we clean out the tangki (tank) in our own houses? You never know what might have gotten into it,” he says.
And while treated water in Malaysia is safe enough to drink straight from the tap, Assoc Prof Azrina says that as an extra precaution, tap water should be boiled before consumption to ensure that all the microorganisms in it have been killed off.
Why we pay more
So, why the need to pay extra money for bottled water, which is significantly more costly than tap water? (See Price comparison)
Sometimes, it is just the convenience of picking up a bottle at the supermarket when you are out and thirsty, rather than having to think ahead and take the trouble of boiling water and pouring it into a tumbler, which you then have to carry around everywhere.
As Assoc Prof Azrina says: “Bottled water is easily available everywhere, and quite affordable, so it is handy.”
Some people also buy the bottled water with an eye towards reusing the plastic bottle to carry around water, as it is generally cheaper than a water tumbler.
However, local environmental organisations have strongly advised against this act as they claim that chemical leaching from the bottle can contaminate the water within if reused.
Consumers Association of Penang president S.M. Mohamed Idris said at a press conference in Nov 2009 that such bottles were made for one-time use only and would not stand up to repeated wear, dishwater treatment, direct sunlight, high temperatures or rough handling.
“Consumers should not refill the plastic bottle with tap water. Studies show that when subjected to stress tests, the bottles are more likely to leach plastic materials into the water the longer the bottles are reused,” he said.
Of course, as Assoc Prof Azrina points out, in times of emergency like floods, bottled water is an essential source of clean, safe water, as sanitation and water treatment processes might be compromised.
Mineral water healthy?
Most people tend to buy bottled mineral water with the vague idea that it is “healthier” than regular tap water.
Mineral water bottles usually display nutrition information panels that show the levels of certain minerals like potassium, sodium, magnesium, and calcium, that the water contains.
Usually obtained from running water sources located underground, this type of water picks up these minerals from the rocks it flows over.
Both Assoc Prof Azrina and Prof Jamil agree that such minerals are essential to our health, and mineral water is a viable alternative source for those elements.
However, Assoc Prof Azrina also points out that water is not the primary source of these minerals for our body.
According to the 2010 Malaysian Dietary Guidelines: “Eating a variety of foods daily as guided by the Malaysian Food Pyramid should provide all the nutrients needed by the body.
“Therefore, supplements are not necessary for most individuals.”
However, it does add that “supplements may be needed to meet specific nutrient requirements such as during convalescence, in pregnant and lactating women, and for the elderly.”
The Guidelines also provide advice on how much water should be drunk daily in order to meet the average body’s needs. (See What to drink)
Both mineral water bottles and distilled water bottles use coloured bottle caps – usually blue or green – as they originate from sources other than tap water. Bottles that contain water, which originate from tap water, have white caps.
All water sources – whether from rivers that go through water treatment plants to become tap water, or underground aquifers – have to be approved by the Health Ministry.
Approval and monitoring of these sources have to abide by the standards and permitted levels of certain heavy metals, elements and bacteria, as laid out in the Food Act 1983 and Food Regulations 1985.
Just pure water
Distilled water, as Prof Jamil explains, should strictly be water that has been heated until it becomes water vapour, and then cooled or recondensed back into liquid water.
This process usually removes all contaminants, as well as any dissolved minerals, in it, resulting in pure water.
However, he says that he has been to certain factories where the distillation is done through a series of resin barriers, which “trap” any contaminants and minerals, and remove them from the water.
The quality of distilled water produced from such a process, of course, depends on the maintenance of the resin barriers, as the more saturated it becomes with the “trapped” material, the less efficient it becomes.
Similarly, reverse osmosis is another method through which pure water, without any minerals or other materials, is produced.
Says Prof Jamil: “Water passes through membranes under pressure, and the membranes will filter out all the salts.”
However, unlike distilled drinking water, which usually comes from underground sources, the source for reverse osmosis water is usually treated tap water.
While it might seem strange that people are willing to pay such a huge price difference for water that comes from essentially the same source, Assoc Prof Azrina says: “Because it has been treated, there is no odour or flavour; that is why some people think it is better than tap water.”
And despite the price difference, bottled water – particularly those from local sources – is still generally quite affordable for most people.
So, while there may not be any significant health benefits in drinking bottled water of any sort, it is, admittedly, a convenient and affordable option for most people.
And it is definitely better to drink more plain water than other beverages containing sugar or caffeine, or not drink any water at all.