Sunday, March 02, 2008

Travelers who don’t trust the water from a mountain stream or a hotel-room faucet have often used chemicals or filters to purify it. Now they have a high-tech option as well: swirl the water with a portable, lightweight wand that beams rays of ultraviolet light.

The wand can clean up a quart of water that is clear — but could harbor stomach-wrecking microorganisms — in 90 seconds. The high-frequency light damages the DNA of bacteria, viruses and protozoa in the water like giardia and cryptosporidium so they can’t reproduce and create havoc.

To make the disinfection process easier for users to monitor, one new device on the market, the SteriPen JourneyLCD($129.95) has a liquid-crystal display that shows a countdown during purification (48 seconds for 16 ounces, 90 seconds for 32 ounces) and a smiley face at the end to signal that the job is done.

The device, which weighs a bit less than 5 ounces, including two disposable batteries. The batteries will last for about 100 treatments before they need to be replaced. The lamp that creates the ultraviolet light, which has a wavelength of 254 nanometers, is good for 10,000 treatments — about 2,500 gallons of water — said Miles Maiden, inventor of the SteriPen and the chief executive of Hydro-Photon.