In December 1992, an outbreak of a new and dangerous strain of cholera began in southeastern India. Within months it had spread into neighboring countries, killing up to 10,000 people. The tragedy inspired Ashok Gadgil, an Indian-born scientist working at the Lawrence Berkeley National Laboratory in California, to look for a new way to purify drinking water. Using science no more complex than the ultraviolet light emitted by an unshielded fluorescent lamp, he built a simple, effective, and inexpensive water disinfection system. Dozens of these systems are now installed around the world.
An approach tailored to developing countries
After the Bengal cholera outbreak, Gadgil and one of his students devised a basic but highly effective water purification system for India and other relatively poor countries. "At the bare bones, using the simplest engineering, we could disinfect water for half a cent per ton. That's shockingly cheap. You could disinfect water for one person, a full year's drinking supply, for a couple of cents."