Monitoring water through a snake's eyes( Although most Americans take the saf...)

Although most Americans take the safety of their drinking water for granted, that ordinary tap water could become deadly within minutes, says Prof. Abraham Katzir of Tel Aviv University's School of Physics and Astronomy.

To combat the threat of contamination due to industrial spillage, natural disaster or sabotage, the physicist has developed a new system to monitor the safety of a building or community's water supply in real time.

Modifying special fibers developed in his Tel Aviv University lab, Prof. Katzir can detect "colors" in the infrared spectrum which distinguish between pure and contaminated water. Not visible to the naked eye, this spectrum is normally only seen by certain animals, like snakes or vampire bats, to track down prey. Connected to a commercial infrared spectrometer, the fibers serve as sensors that can detect and notify authorities immediately if a contaminant has entered a water reservoir, system, building or pipeline.

In the lab, the fiberoptic system detected poisons such as pesticides in amounts well below the World Health Organization safety threshold. Preliminary field experiments have already been done at several European sites, and the results were reported recently in the Journal of Applied Spectroscopy.

The Colors of Danger

Once in use, the sensor system would be one of the first real-time water monitors in the United States to provide protection from chemoterrorism attacks ― a threat to which U.S. water supplies are particularly susceptible. "It's unlikely that someone will poison the water supply in Afghanistan," says Prof. Katzir, "but America is in grave danger and needs to arm itself against chemical threats to its drinking water.

"With our naked eyes we can't distinguish between pure water and water that contains a small amount of alcohol or acetone. They're all clear. We can't do it even with a spectrophotometer, which measures visible colors," expl
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