Water-Pure and safe?

A recent report claiming that most water purifiers in India do not completely eliminate water- borne viruses like Hepatitis E has aroused concern. But experts say that the chemical poisoning caused by prolonged use of water purifiers is a greater health threat. We check the facts

IF THERE'S one thing we Indians should be afraid of, it's drinking the water in our own country. Like it or not, the reality is that the water that comes out of our taps is laden with chemicals and microorganisms. One casual sip of unprocessed water can result in an episode of typhoid, jaundice or amoebic dysentery. Despite our awareness of the consequences of drinking ' impure' water, most of us are confused about how we should process water to make it safe and healthy for drinking.

It's this very confusion that manufacturers of water purifiers cash in on. There are half a dozen of branded players such as Eureka Forbes, Hindustan Unilever, Ion Exchange India, Usha Shriram Brita, Tata Chemicals and Kent RO System competing with each other for the biggest share in the market.

Every brand of water purifier claims to be better than its competitor. " Don't get swayed by marketing gimmicks. Buy a water purifier based on your needs and the quality of water in your area," says virologist Dr A K Prasad.

One way to keep your water contaminant-free is to boil it. " Boiling water is an ideal way to remove both microbes and viruses, which most purifiers don't do," says Dr Narendra Saini, consultant, Global Hygiene Council.

The trouble is that today's hectic lifestyle doesn't allow the luxury of time needed to boil water. Also, a concern raised by experts is that though boiling frees water of microbial impurities, it cannot completely remove hazardous pesticides such as lindane, malathion, solvents, etc. Therefore, to protect yourself and your family from water- borne diseases, water purifiers have become inevitable.

Nowadays, most water purifiers in the market run on reverse osmosis (RO), ultra- violet (UV) treatment and filtration or chemical purification. Here we help you in finding a water purifier that suits your needs.

CHEMICAL BASED PURIFIERS

The cheapest of the lot, storage water purifiers are becoming hot selling items as they do not require electricity or running water to operate and don't pinch the purse. In fact, last year Tata launched a storage water purifier 'Swach' priced at Rs 999. However, despite their advantages these storage water purifiers have run into controversies because of the chemicals they rely on to disinfect water. According to experts, there is an overdose of these. The residues of these chemicals are toxic and could cause chemical poisoning in the long run, which is becoming a concern in the developing world where many deaths have been reported from it.

Some months ago, Healthy You Foundation, a consumer health organisation, raised concerns over storage water purifiers which use an overdose of chemicals such as chlorine to kill bacteria and viruses. All the five popular brands which were studied in its report failed to disclose the form of chemicals used and the residues of chemicals the purification process leaves behind in their product to consumers.

"Some of the brands use chemicals which aren't meant for disinfecting drinking water whereas others use the right chemicals but in doses much higher than necessary," says Bejon Mishra of Healthy You Foundation.

Experts say that there is no absolute way to determine the safety of storage water purifiers as most companies don't disclose the chemicals used in the process. For instance, the popular brand PureIt has been accused of using a form of chlorine known as TCCA which is used worldwide predominantly for sanitising swimming pools and is not approved as drinking water disinfectant in a water purifier.

YOU SHOULD KNOW

One way to ensure if the purifier is capable of removing chemicals, which were used in the purification process is to check the taste of water after the filtration.

Nowadays purifiers come with ' auto shut off ' feature which means it gets switched off when the chemical which disinfects the water finishes.

However, what most brands won't tell you is the expiry date of the ' polisher' which washes off the toxic dosage of chemicals and its residues. " Get your polisher changed in time as it protects you from toxic residuals of the chemicals," says an industry expert.

Although chemical- based water purifiers such as PureIt, AquaSure and Swach claim to kill viruses, the same can't be said about purifiers such as Kent Gold which use non- chemical filtration technology such as hollow fibre based filtration technology. " Such technologies wouldn't pose a chemical safety issue as the underlying technology does not use germ- killing chemicals but at the same time it won't protect you from viruses either," says Mishra.

ELECTRIC WATER PURIFIERS

THE more expensive the water purifier, the better it is, or so most of us believe. Many Indians are going for high- end RO and UV based water purifiers without considering the quality of water in the area they reside in.

Both RO and UV based purification systems have their own benefits and downsides and it's best to figure out whether they are likely to suit your requirements.

REVERSE OSMOSIS

Reverse osmosis purifies water by using pressure to force water through a membrane that retains the contaminants on one side and allows pure water to pass to the other side. The high quality semi permeable membrane ensures higher purification of water by trapping 99 per cent impurities and dissolved solids, including salt. " RO is the only purification system which removes hardness as well as total dissolved solids from your drinking water," says an industry expert.

However, this form of filtration process works best where the water is hard or salty in taste.

Also, RO is a slow process and requires more time to purify the water. It wastes a lot of water while it is running. Typically, it wastes nearly four litres of water to produce one litre of pure water.

So, it can be a bad choice for areas where the supply of water is unpredictable.

According to experts, another concern with RO technology is that a lot of essential minerals in water get lost in the purification process. Drinking RO water for a longer period may even lead to a deficiency of natural minerals.

Also, it reduces the pH levels of water which can cause imbalances in the body.

YOU SHOULD KNOW

RO is suitable for areas where the water is hard and saline or where water is sourced from bore wells or deep tube wells.

Experts advise the use of RO systems only where Total Dissolved Solids ( TDS) levels are above 500 mg per litre. Best is to get the quality of water in your area tested by sending it to a laboratory such as Delhi Water & General Test Lab.

Though advanced and efficient, RO purifiers are expensive and require maintenance. Their filters have to be changed to avoid growth of bacteria. So, buy them if it suits your pocket.

The semi permeable membrane used in a reverse osmosis purifier wears off fast if it is of inferior quality. So, choose a brand that is covered by an adequate warranty agreement.

UV PURIFIERS

THE most popular in India, UV system uses UV light to cleanse bacteria and germs without altering the taste of water. The biggest advantage of UV system is that it doesn't introduce any toxic byproducts and doesn't change the chemical composition of water. However, it is essential to choose UV system with an effective carbon filtration. This is because UV system only cleanses biological contaminants and not heavy metals, pesticides, chlorine and other chemical contaminants.

YOU SHOULD KNOW

A UV system is not a good choice in areas with salty or turbid water. It is only meant for places where the water is treated to a certain extent before it reaches homes or where the source of water is a river or lake.

This is because UV system is not good at removing dissolved solids.

Buy UV system with activated carbon or other filtration method.

DO THIS

Fibre is the secret to losing weight without going hungry. A recent study says that those who increased their daily fibre intake from 12 grams to 24 absorbed 90 calories lesser per day than those who ate the same amount of food but less fibre. Eating a bowl of oats for breakfast is one way of upping your fibre.