Summer temperatures and water-borne diseases such as hepatitis, typhoid, cholera and gastroenteritis go hand in hand. So besides maintaining good hygiene, it is also important to monitor and maintain the quality of drinking water to prevent these diseases.

Drinking water sources

The source of drinking water supply at home is either surface water or groundwater. Unfortunately, most of these sources are not safe for drinking without proper treatment due to the presence of microbial and chemical pollutants. Toxic chemicals and harmful bacteria pollute water sources, thereby causing sickness and also exposing us to long-term health consequences such as liver and kidney damage.

The Water Works Departments in cities treats the water before supplying it but the water comes in contact with pathogens and certain chemicals during the transportation process through the distribution network. This means that the water needs to be tested and treated at the point of use as well. For testing the water, simple low-cost kits are available in the market and for treating the water, various water filters are also available.

Water purification at home

A good water filter at home is the only way to ensure the quality and safety of drinking water but all filters have their own advantages and limitations.

There are different methods available to purify water at home. Some are listed below along with their pros and cons:

1. Boiling

• Kills germs but does not remove heavy metals and minerals
• Method is not fuel-efficient
• Chances of microbial recontamination if water is stored for a long time

2. Candle filters

• Inexpensive
• Can remove bacteria, protozoa, microbial cysts and suspended impurities
• Requires regular maintainance
• Simple and unsophisticated method,  so people do not wish to buy it

3. UV filters

• Purify water by deactivating the bacteria but dead organisms still remain

4. Reverse Osmosis (RO) filters

• Said to be the most efficient of all
• Can remove 90-99% of all contaminants in water
• Popularity steadily grown over the years

Of the ones mentioned above, RO filters are more popular among urban residents, so let's have a closer look at its pros and cons.

Efficiency of RO filters

Studies have confirmed that RO systems remove unhealthy contaminants present in water. Unfortunately, along with removing unwanted chemicals, microbes and compounds, they also remove a significant portion of the minerals found in water, especially calcium and magnesium. These two elements are among the seven major dietary elements required by our body for stronger bones, teeth and normal muscular and nerve functions.

Problems linked with RO water

Reverse osmosis was developed as a water treatment method over 40 years ago. The process was used primarily to de-salinate water but later on it was used in home filters. There are many problem linked with drinking RO water:

• The water is demineralized and drinking de-mineralized water (water devoid of essential minerals) is not healthy. A few of the health risks include gastrointestinal problems, bone density issues, joint conditions, and cardiovascular diseases.
• Removing the naturally occurring minerals also leaves the water tasteless. One may add some liquid ionic minerals to the RO drinking water. However, doing so will not be as beneficial as drinking water that contains minerals naturally.
• Prolonged use of RO water (for several months or years) reduces the body’s immunity and can make you fall sick more often.
• Removing the minerals makes the water acidic and drinking acidic water on a regular basis might cause acidosis in the body, which is considered an underlying cause of most degenerative diseases.
• RO produces more wastewater than purified water, meaning for every litre of RO purified water, a higher quantity of wastewater is generated.

Water benefits health 

Drinking the right amount of the right type of water improves every function in the body and even slows down the aging process. It is said that our body can absorb up to 30% of essential elements from the water that we drink. So it is very important for our long term health that we drink that water which is not devoid of at least the essential elements like calcium and magnesium.

If your health is a top priority and you don’t want to be drinking de-mineralized water, invest in a water filter that best suits your needs. The aim should be to minimize microbial and chemical load in water. 

What you can do

Testing the water on a fortnightly basis will tell you the level of different components including the presence of bacteria in water. If these components are within the permissible limits set by the Bureau of Indian Standards, then for your own satisfaction you can make use of a simple water purifier like a candle filter or a silver nano technology based filter.

Simpler and low cost technologies might work better for majority of the people in India. RO water should be consumed only when you do not have an alternative, for example when you are travelling or when you visit a new place and you are not sure about the water quality.

Home grown solutions

It has been found that a handful of tulsi leaves can decontaminate about 20 litres of water. The solar water disinfection method (SODIS) is also a simple procedure to disinfect drinking water. Contaminated water is filled in a transparent PET-bottle or glass bottle and exposed to the sun for 6 hours. During this time, the UV-radiation of the sun kills the pathogens in the water.

These renewed water treatment options could provide India’s poorest people an opportunity to remove contaminants from their drinking water without any side effects. Whether it is tulsi, tomato peels, bio-sand filter or copper water purifier, more research is needed to identify and validate their effectiveness and to popularize them.

Future strategy

Some water filter manufacturing companies are distributing their RO filters in rural areas under their CSR initiative to provide safe drinking water. Are they really concerned about the health of the people in the long run or is it only their marketing strategy?

What is needed is a water filter which can decide what to remove and what to retain in water, depending upon the situation and the components of the water in a particular area. Companies should invest in research, manufacturing and marketing of safe and cost-effective products.

However, till such products are available, there is no need to panic. Just conserve water, be informed and stay healthy!

The author is with Peoples’ Science Institute, Dehradun and the opinions expressed here are her own.