New Device Cleans Water With Light - Saves Lives In Developing Countries

An off-shoot of Berkeley Lab's research into fluorescent lighting could prove to be a life-saving gift to the children of developing countries. More than 400 children die every hour as a result of water supplies being contaminated with such diseases as cholera, typhoid, and dysentery. Berkeley Lab scientists have developed a simple device that uses the same ultraviolet radiation (UV light) produced in fluorescent lamps to disinfect water. This device, which is a stainless steel chamber about the size of a microwave oven, can be fitted directly into the plumbing of a water source such as a community hand pump. As water passes through the chamber, it is bathed in UV light, which kills viruses, molds, and other pathogens by inactivating their DNA.

The system can disinfect water at a rate of four gallons per minute (similar to the flow from a typical bathtub spout in the United States) at a cost of pennies per ton. It is currently being field-tested in India, where recent cholera epidemics from contaminated well water have killed thousands of children.

"The device has tremendous potential to save lives," says physicist Ashok Gadgil, a researcher in the Lab's Energy and Environment Division who is developing the device. "It gives communities in developing countries a central place for collecting disinfected water." Last fall, Lab researchers shipped devices to the Virgin Islands for disaster relief in the wake of devastating hurricanes that left much of St. Thomas and neighboring islands without safe drinking water.

As an added benefit, the use of these UV devices could replace the common practice in developing countries of boiling water over wood-burning stoves, which contributes to the problem of deforestation.