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,"
explains Prof. Katzir. "But we can clearly distinguish between liquids
using an infrared spectrometer which can distinguish between 'colors' in
the invisible infrared spectrum."
Such an instrument can be used to detect hazardous chemicals,
pollutants and threats in the water, "seeing" water in the same way as a
snake does. The special fiber sensors make it possible to monitor the
quality of water in a remote location, such as a lake, a river, or a
pipeline, and detect trace amounts of contaminants in real time, adds
Prof. Katzir. Water management executives in Florida's Everglades and
officials in Germany are among those who have expressed an interest in
using the technology.
Skyscrapers in New York City a Likely Point of Attack
Toxic materials are readily available as pesticides or herbicides in
the agriculture industry, and can be harmful if consumed even in
concentrations as low as few parts per million," says Prof. Katzir.
Cities like New York are especially susceptible to a chemoterrorist
threat. With many skyscrapers holding water reserves on the top of the
building, a terrorist only needs to introduce poison into a tank to wreak
havoc. "A terrorist wouldn't have to kill tens of thousands of people.
Only 50 deaths — as horrible as that would be — would cause nationwide
panic."
Currently, water authorities in America test water reservoirs usually
once every day or two, with no system in place to detect chemical threats
instantaneously. "This new system can cut millions of dollars from the
cost of testing water manually." The fiber sensors developed by Prof.
Katzir are made of insoluble, non-toxic, and biocompatible materials. "You
can eat them and nothing will happen to you," he notes.
Prof. Katzir's determination to fight terrorism through science has a
personal side as well. His father, world-renowned scientist Prof. Aharon
Katzir, was assassinated by the Japanese Red Army in a terror attack in
1972. "I am trying to walk in his footsteps by doing applied research that
can be a practical tool in an important battle. This system can be ready
for use in less than a year."
SOURCE: American Friends of Tel Aviv University