Ancient Indian wisdom that drinking water should be stored in brass vessels for good health has now been proved scientifically.
Microbiologists say water stored in brass containers could help combat many water-borne diseases. In developing countries, such containers should be used rather than their cheaper alternatives, plastic containers, researchers said.
Water-borne diseases remain a serious threat in many poor regions of the world, with around 2 million children dying each year from diarrhoea. Efforts to provide safe drinking water have had difficulty reaching remote areas.
Even in places with basic water-purification systems, people often opt for riskier wells under trees because the water is cooler, 'Nature' magazine quoted Rob Reed, who led the research, as saying.
It said on a recent trip to India, Reed, a microbiologist at Northumbria University in Newcastle upon Tyne, United Kingdom, witnessed villagers doing exactly this.
But he also heard an interesting piece of local wisdom: people believe that traditional brass water containers offer some protection against sickness. The idea, Nature added, intrigued Reed, who was in Asia investigating the anti-bacterial effects of sunlight on water.
He has now found that bacteria are indeed less likely to thrive in brass water pots than in earthenware or plastic ones. "It's one of the traditional ideas of water treatment and we were able to find a microbiological basis for it," he was quoted as saying.
Reed, with his colleagues Puja Tandon and Sanjay Chhibber, carried out two series of experiments, 'Nature' reported.
In Britain, the researchers filled brass and earthenware vessels with a diluted culture of Escherichia coli bacteria, which can cause illnesses such as dysentery. They then counted the surviving bacteria after 6, 24 and 48 hours. A similar test was carried out in India using naturally contaminated water.
The amount of live E coli in the brass vessels dropped dramatically over time, and after 48 hours they fell to undetectable levels, Reed told the Society for General Microbiology's meeting this week in Edinburgh, UK.
The key to the result is copper, which can disrupt biological systems, Reed explained. The element interferes with the membranes and enzymes of cells; for bacteria, this can mean death.
Pots made of brass, an alloy of copper and zinc, shed copper particles into the water they contain. The amounts that circulate into the brass water vessels could not harm humans, Reed added.
Even a person drinking 10 litres of such water in a single day would take in less than the daily-recommended dose of copper or zinc, Nature quoted the researchers as saying.
Brass water pots also easily outperformed plastic ones, the researchers discovered. Plastic, Reed was quoted as saying, did not inactivate the bacteria. But many people in developing nations use plastic drinking vessels, because they view them as more modern.