A $3 life-saving straw

A Danish company has come up with a clever invention it hopes will slash the death toll from water-borne diseases which claim some 6,000 lives a day in developing nations.

The Lifestraw is designed to make dangerous water drinkable. The plastic tube has seven filters which remove at least 99.99 percent of many parasites and bacteria from water, according to a report in the New York Times.

Vestergaard Frandsen, the textile company behind the invention, is already developing a toddler version of the tube which will be squeezable.

The Lifestraw can be worn on the neck, lasts a year and costs as little as $3 to manufacture. Some 70,000 have already been handed out to survivors of last year's earthquake in Kashmir.

It is less effective against viruses, and it doesn't filter out metals like arsenic. But in villages where the only water source is a filthy pond it could prove a lifesaver.